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A look at Garmin’s new ANT+ Speed & Cadence magnet-less sensors


(** Update: These sensors have since been updated. Check out the newest generation Garmin Speed and Cadence Sensor V2**)

While these sensors were announced a month ago at the same time as the Edge 1000, photographic information about them has been harder to come by than that of little green men in Roswell, NM.  There were rough sketches released at launch, but otherwise nothing of use.  Thankfully, I now have units in my possession and am able to answer a bunch of the questions folks have been shooting my way about them.

So while my Edge 1000 review is still forthcoming (I just recently got a final production unit with final software), I figured I’d dive into the sensors since those are a bit easier to talk through.

The first thing to know is that unlike Garmin’s past GSC-10 Speed/Cadence Combo sensor, these are two separate sensors.  One sensor for speed, and one sensor for cadence.  The two don’t talk to each other, and don’t have any dependencies on each other.  It’s two separate products, though Garmin does offer a bundle where they just stick the two products in the same box and you save a bit of cash.  Let’s dive into them individually in more detail:

The Cadence Sensor:


The cadence sensor has two basic pieces: The sensor and the rubber band.  Within the package there are three rubber bands for different size crank arms.  I found that on my bike I needed the medium sized band, as the small one was too small and has very little elasticity.  There is no magnet here.  It simply uses an internal accelerometer to determine circular rotations.


From there you’re apply it to the non-drive side of the crank arm (that’s the side without your gears).  If you apply it to the other side, the entire setup will last approximately half a revolution before being sheared off and conveniently removed for you.


The rubber band is pretty ingenious in that it’s got three channels that keep it from flopping around off-center.  Further, the unit itself has a rubber backing so it won’t slide anywhere.


After getting it all configured, it’s time to head on for a ride.  I first started with an indoor ride.  Indoor rides are the easiest things for any cycling product, as it removes bad road conditions which can often cause troubles.

Below, I rode across a bunch of cadence values from the 50’s all the way up to the 120’s.  As you can see, up until about 120RPM, things are perfectly fine.


I’ll be looking at the higher cadence ranges over the next few weeks, as well as the lower ranges.  Most units have a high/low range for acceptable cadence, and those are areas I want to dig into a bit more.

Finally, let’s look at a short city ride I did, including a nice long mostly cobble-filled section.  I use this same section all the time for doing testing, since it’s easy for things to come up here.  In this case I’ve truncated the data a bit to just focus on the roughest section of the road.  Further, I removed out the stopped periods with typical city traffic, thus leaving basically the actual pedaling portions.


In the above, orange is the new Garmin magnet-less sensor, while blue is a magnet sensor, and grey is Garmin Vector.

What you see is that while there is a tiny bit of noise (just like indoors) – overall it still tracks fairly well, especially the accelerations.  And while it appears there might be a 1-second delay on some of the quicker accelerations from zero, that’s hard to quantify due to a lot of factors involved in the transmission and capture process – even with everything in sync.

Lastly, just for reference, I’ve added the order of precedence for cadence senors as shown on Garmin devices (it can differ in other vendors):

1. Power meter sending torque and cadence (e.g. Vector, SRM, Quarq)
2. Standalone cadence sensor (or combo speed/cadence sensor)
3. Power meter sending power values and cadence (e.g. Power2Max, Rotor)

There is no way to change this order on any devices on the market I’m aware of, except a few apps such as the Wahoo Fitness app.

The Speed Sensor:


The speed sensor is a single unit that requires no additional rubber bands.  It does however actually sit inside a little rubber casing that includes the rubber band portion built into it with lots of elasticity:



The elasticity of the band is impressive.  It both fit around a typical wheel hub, as well as my PowerTap hub, which is diameter-wise huge:


It’s really that simple to install – very easy.

So let’s look at some data.  This first piece was taken indoors on a trainer ride of mine.  In theory this would be about as perfect as the data should look – since the wattage was controlled and thus the speed tends to be fairly ‘clean’.

The first chart is of raw data from the WASP data logger, which captures all the data at the full resolution (up to about 4-times a second for most ANT+ devices).  Below is not actually showing speed, but rather wheel RPM.  That’s just the way the data gets spit out in this case from the logger.  By doing so I remove any concern about proper wheel size values.

As you can see, the grey track is the new Garmin sensor, while there is a blue and orange track hidden behind it all is the old-school speed magnet sensors (one as part of a combo sensor, and one as part of a speed-only magnet sensor).


Of course, those two trusty sensors are hard to see with all the craziness of the Garmin sensor laying on top of them.  So let me just remove the Garmin sensor from the picture to make it clear:


As you can see, those two sensors were very close together.  The little part in the middle where there’s variation is where I was doing one-legged drills, thus the speed isn’t as constant, because I’m not as constant in pedaling there.  Otherwise, it’s incredibly precise.

But, does that really mean anything?  Meaning – does that funkiness matter at the end of the day?  Well, let’s start with two graphs.  First up is from the Edge 1000 showing the speed data being fed to it from the new Garmin speed sensor.  As you can see, it’s smoothed a little bit.  That’s partly because Garmin Connect does some smoothing, and partly because the data capture rate is lower (only once per second) – which naturally cleans things up.


(Note: You’ll see a gap above, that’s where I stopped and calibrated power meters – it’s removed from the higher quality WASP data to make it easier to compare for other tests I was doing)

But now let’s look at data captured from another Edge unit that was connected to one of the older magnet based speed sensors:


Ahh…much cleaner!

But again, what’s the end resultant on distance, or speed?  Well, for speed the units actually displayed very close the entire time.  It’s just not that visible to the human eye versus the graphs.  As for the distances, here’s the total from both units:



Totals in text:

New Sensor: 28.24KM (17.54mi)

Old Sensor: 27.98KM (17.39mi)

A difference of: .9%

Now, one thing to consider in the above difference number is that those are from Edge units, which are using different calibration values (both based on automatic configuration).  The new cadence sensor had an automatic configuration of 2097, versus my others having 2088.  Thus, that’s a difference of 0.4% in and themselves.  So if we go ahead and subtract that it could be as little as half a percent (assuming linear).  So the actual difference could be:

Potential difference range: .5%-.9%

Again, like I noted above – I’ll be getting more examples as part of my Edge 1000 review – including seeing what happens if I override the automatic configurations on both and set to the same values.

Next, a brief look at the same outdoor cobbles section that I noted earlier, as part of my short outdoor ride.  Here’s the speed between the different sensors.  Note again we’re looking at RPM of the wheel and not the actual speed:


(Edit/Update/Note: Garmin believes that the noisiness of the speed sensor I’m seeing is due to placing it on a PowerTap wheel, which they believe is introducing interference.  They suggested instead putting it on another wheel.  In doing that, I’m seeing much better results – which I’ll summarize in my Edge 1000 In-Depth Review.)

Just like everywhere else we see the same noisiness of the speed sensor.  While the data isn’t clean, it’s in the ballpark, and one has to keep in mind that wheel revolutions is a slightly different metric than straight speed.  Further though, the speed sensor is of less value if outdoors where GPS is most often used in a typical outdoor configuration, though, the speed sensor would override the GPS for Garmin units.  That wouldn’t be necessarily true though for all ANT+ units.  Here’s the order of precedence for Garmin units on the speed sensor:

1. Power meter sending torque and speed (e.g. PowerTap). In this case wheel speed is needed to compute power.
2. Speed sensor
3. GPS

Note that unlike running footpod’s, there is no method to change which sensor (or GPS) to use on a Garmin unit for cycling speed.

So would I recommend the speed sensor from a data standpoint?  For most riders, they realistically won’t likely even notice the noise.  Ultimately it’s giving you the basically same speed (albeit with a bit of noise that’s barely noticeable), and it’s giving you basically the same distance.  But really for most folks would use GPS outside anyway, so it’s really just indoor training where you might be using some sort of app that utilizes speed.

But there are some use cases where I wouldn’t recommend it.  For example, if doing aero testing (such as with Alphamantis), this speed sensor would be a nightmare and skew the data too much.  Same goes for any other scenario that relies on incredibly clean and high fidelity speed sensor data.  If you’ve never put those words together in the same sentence before, then you likely don’t fall into that camp.  Also of note is that I haven’t done any mountain biking.  While the cobbles I do have can throw a wrench in things, so can rocks and stumps.  So just keep that in mind if you’re looking to go on trails instead.

Like anything else, it appears to be a balance between convenience and accuracy.  If you want super-high accuracy – go with the magnet.  But for most folks, it’ll likely be a wash.

Compatibility with units:


Now it’s important to note that because the two sensors don’t use the ‘combo’ ANT+ profile that some devices don’t support them.  Mostly older devices.  These days almost everything major on the market supports the three core profiles of: Speed-only, Cadence-only and Speed/Cadence combo.  To refresh, here’s how those three profiles are applied in real-life:

ANT+ Speed-only: The new magnet-less speed sensor
ANT+ Cadence-only: The new magnet-less cadence sensor
ANT+ Speed & Cadence Combo: The older GSC-10 combo sensor

Got it?  Ok, good, let’s talk compatibility.  Below is a chart I’ve put together after manually verifying compatibility with each sensor type.  If there are more down the line that others are able to validate I can easily add them to the chart, but I wanted to keep it to things I’ve physically validated rather than just assumptions.

Updated (twice): One final thing to note: Some older Garmin units only support concurrently connecting to EITHER the speed-only sensor or the cadence-only sensor (or a combo sensor).  Basically, the pairing menu only allows you to connect to one sensor in that category.  I’ll try and get this added into the table, but it’s going to take a bit more time since I’m travelling. I’ve confirmed that the Edge 500/510/800/810/1000 all are fine, as is the FR910XT, Fenix2.  The vast majority of non-Garmin units support it just fine since those companies often sold the single-profile sensors (whereas Garmin never did).  On your unit, you’re looking for the menu option that says “Speed and Cadence Sensors”, as a separate line from Speed/Cadence sensor and Speed-only and Cadence-only sensors.  So if you have four categories to choose from, you’re good. Three categories – then you’re limited on concurrent sensors.

ANT+ Speed and Cadence Sensor Compatibility Matrix

Product NameANT+ Cadence-only SensorANT+ Speed-only SensorANT+ Speed & Cadence Combo Sensor
Garmin Edge 200NoNoNo
Garmin Edge 500YesYesYes
Garmin Edge 510YesYesYes
Garmin Edge 705NoNoYes
Garmin Edge 800YesYesYes
Garmin Edge 810YesYesYes
Garmin Edge 1000YesYesYes
Garmin FenixNoNoYes
Garmin Fenix2/2SEYesYesYes
Garmin Fenix3YesYesYes
Garmin Forerunner 10NoNoNo
Garmin Forerunner 15NoNoNo
Garmin Forerunner 60NoNoYes
Garmin Forerunner 70NoNoYes
Garmin Forerunner 305NoNoYes
Garmin Forerunner 310XTYesYesYes
Garmin Forerunner 405NoNoYes
Garmin Forerunner 410NoNoYes
Garmin Forerunner 610NonNoYes
Garmin Forerunner 620YesYesYes
Garmin Forerunner 910XTYesYesYes
Garmin Forerunner 920XTYesYesYes
Garmin TactixYesYesYes
Garmin TouringNoNoNo
Garmin Touring ProNoNoNo
Garmin VIRBNoNoNo
Garmin VIRB EliteYesNoYes
Garmin VivoactiveYesYesYes
Garmin VivofitYesYesYes
Garmin Vivofit2YesYesYes
Magellan SwitchYesYesYes
Magellan Switch UpYesYesYes
Mio Cyclo 505NoNoYes
Motorola MotoactvYesYesYes
O-Synce Navi2CoachYesYesYes
Polar products (any/all)NoNoNo
PowerTap JouleYesYesYes
PowerTap Joule 2.0YesYesYes
PowerTap Joule 3.0YesYesYes
PowerTap Joule GPSYesYesYes
Suunto AmbitYesYesYes
Suunto Ambit2YesYesYes
Suunto Ambit2 SYesYesYes
Suunto Ambit2 RNoNoNo
Suunto Ambit3 (all models)NoNoNo
Timex Cycle Trainer 2.0MixedYesYes
Timex Global TrainerMixedYesYes
TomTom Products (any/all)NoNoNo
Wahoo RFLKT+YesYesYes

Note that you can also use the ANT+ directory to validate compatibility as well.  This has the handy benefit that they’ve done the work on the validation piece, so they’ll likely cover other devices than what I’ve covered above (which are the most popular ones out there).

Here’s the link to all the devices currently compatible with the new cadence sensor.  And here’s the link for the speed sensor compatibility.  And, for completeness, here’s the table of the sensors in question with prices:

Garmin Cadence-Only ANT+ Sensor (magnet-less)
Garmin Speed & Cadence ANT+ Sensor bundle (magnet-less)
Garmin Speed-Only ANT+ Sensor (magnet-less)



I’m not seeing any major issues yet with the sensors, either indoors or outdoors.  Though, I’ll dive into more detailed testing and comparisons as part of my Edge 1000 review and see if something sneaks up – especially around edge cases (high/low cadence, rougher sections of road, etc…).  This mostly serves as as stop-gap to stem the flow of questions.

Would I recommend you buy the new sensors?  Well, that depends a little bit on whether you have sensors today.  My feeling is that if you already have perfectly functional ANT+ speed and/or cadence sensors today and they work just fine with your bike setup – then I’d probably hold off.  Why’s that?

Well, companies like Wahoo and others have clearly stated they plan to deliver dual ANT+ & Bluetooth Smart sensors by the end of the year.  In fact, in checking with them yesterday, Wahoo will be shipping an updated version of their Wahoo RPM magnet-less sensor in just four weeks (same $49 price), which will be dual ANT+/Bluetooth Smart, and also include a new shoe clip (so you can easily wear it at the gym on spin or exercise bikes, etc….).  And they’ve got a firmware update in the works to get higher accuracy while worn on the shoe (for both current and future RPM models).

This new RPM will do the exact same thing as Garmin’s cadence sensor – except it’ll broadcast on two frequencies instead of one.  They shipped out a version of the new unit yesterday to me, so I’ll be able to start testing it side by side with the Garmin pods over the next few weeks.

Now, to Garmin’s credit here their cadence pod mounting system is far better than Wahoo’s current pod design, as far as portability goes.  And I did confirm that Wahoo’s current pod mounting system will be retained for at least the June version.

While we’re at it, Wahoo does still have plans for an updated Blue SC Speed/Cadence combo sensor later in the year (dual-ANT+/BLE), and are determining whether there will be enough demand for a speed-only model as well.  Lastly, I don’t expect Wahoo to be the only game in town come the fall with products typically introduced at Eurobike and Interbike.

So to that end, while I like Garmin’s new sensors and wouldn’t have any immediate issues with recommending them, what I’ll be doing is getting one of each of the Garmin units purely for test purposes – but I won’t update all my bikes to the new sensors.  I prefer instead the ability to easily get access to both protocols – though, that may be because I’m often testing devices from both camps.  So look at your situation and figure out whether having dual matters to you or not.  If not, you can save a bit of cash ($10), and if so, just wait a few weeks to see how things play out.

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Garmin Cadence Sensor V2 – Competitive Cyclist
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For European/Australian/New Zealand readers, you can also pickup the unit via Wiggle at the links below, which helps support the site too!

Garmin Cadence Sensor (EU/UK/AU/NZ – Wiggle)
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Thanks for reading! And as always, feel free to post comments or questions in the comments section below, I’ll be happy to try and answer them as quickly as possible.

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  1. Hi Rey, The speed sensor that you attach to the hub, could you use it on a wheel like HED H3?

    • Unfortunately my H3’s are in a storage unit at the moment, so I’m not quite sure honestly. Probably won’t be able to get them out till end of month. That said, I might be able to fake it by using two spokes on a regular wheel to simulate the same angle/position. Can try it this weekend when I get back home.

    • ivo

      hey ray!

      i hope i don’t ask this question again (couldn’t find anything here within the 450 posts), but did you ever try to use the speed sonsor on your HED? just got the edge 1000 bundle with these new sonsors but i have a pair of xentis mark 1 on front and back so no wheel hub 🙁 does it work just to put the speed sonsor on a “big spoke” or another place? if not… which “speed-only” sonsor you would recommend for the edge 1000 (in combination with the garmin magnet-less cadence sonsor)?

      thank you in advance for your help!

    • Still in storage, but some other reader noted it wouldn’t work sideways unfortunately.

      So, the best bet at this point is something like the Wahoo BlueSCv2 (dual ANT+/BLE), and then using a magnet through a ziptie on the wheel itself. I can’t remember the exact $3 magnet offhand, but I know if you search for HED3 wheel magnet, there’s some good examples. It’s basically the combination I have on mine.

    • ivo

      oh what a pity. i thought i could avoid the magnet on my wheelset. anyway… thank you very much for your help! by the way… thank you as well for your amazing blog!! my absolutely “decision-helper” for all my sports-gadgets 🙂

  2. Keiths

    28.24 / 27.98 = 1.009

    is .009 variation, or .9% variation.

  3. Hanafiah

    How about forerunner 610? Thanks.

  4. Thank you for this review. I guess that this way, the cadence sensor is more reliable.

    Unfortunately, I’m not a huge fan of the wheel tube cadence sensor, but if it does the job… I guess we can fix it on the front wheel too, no ?

    • The speed sensor yes, but not the cadence sensor since it would be measuring the wrong thing.

    • Yep sorry, I meant the speed sensor, not the cadence sensor, of course 😉

    • Is it possible the speed sensor will work better on a larger-diameter hub than smaller? Just thinking that, if it’s an accelerometer, the greater swing and longer period of time between positive and negative accelerations might quiet out some of the noise.

    • Possibly, though, the PowerTap is about as big as you get. Conversely, they think some of the electronics in the PT hub may have disturbed things. In a test I did on Sunday, it was definitely a bit cleaner with just a regular wheel hub (no PT). I’ll keep poking at it.

    • Mr Nofish

      At constant speed, the angular velocity is also constant so the time for a revolution is always the same, regardless of the hub size, unless there is slipping between the sensor and the hub.

      The only difference is that on a bigger hub the velocity of the sensor is higher because it has to cover a bigger distance in the same time. The same holds true for the centripetal acceleration.

      Since the sensor sees the sum of g plus whatever accelerations it is subjected to (i.e. noise), a smaller hub might actually be better – but I suspect this makes no difference in practice.

    • Mr Nofish

      Ray, you could also try moving it to the front wheel,

    • Yes, it’s on my list of things to try out as well. As noted somewhere, things seemed a bit cleaner on a non-PT wheel.

  5. Bart

    Hi Ray,

    you mentioned that these things see circular motion to determine RPM. How do they work on horizontal linear motion? I’m looking for a solution to track my indoor rower’s strokes per minute. That is a 70cm movement back and forth in the order of 25-40 strokes per minute. Think the cadence unit can pick it up?

    • Scott Buchanan

      Footpod should work

    • hannahba

      @Bart: Finally, someone on the same mission …

      I took my old Kettler rower (magnetic break) apart to find out how it works and tried all kinds of sensors (Garmin S&C, Garmin Footpod, Ipod with various apps) in different positions (wheel, wheelhouse, moving seat, seat moving towards one point, holding sensor in hand … nothing really works.

      So, yes, Ray, would this work on an indoor rower?

    • hannahba

      @Scott Buchanan: Have you tried it? How and where did you position it?

    • Bart

      Tried a nike+ sports footpod to track something – nope.
      Tried a garmin ant+ footpod in several positions on the rower: no movement or very erratic signal.
      Tried mounting pods (cadence or rpm) on the rotor – works somewhat, but fixing them is pure hell as that little rotor spins at quite high rpm and reverses direction every few seconds throwing the sensor either off or confusing it completely.

      Basically, what I want to track is my stroke cadence as that is determining my effort (the resistance setting is the other important setting, but that is a manual switch – and can be captured in a combination of strokes and heart rate) and regularity. And it should not be too difficult, as my rower has a little display showing the stroke and rowing speed/distance. If only those sensors were ant-compatible…

      Any good suggestion is welcome (besides investing in a Waterrower – and there the ant part is heartrate only). It needs to work on a FluidRower E-316 😉

    • Sai To

      You can tape any cadence sensor (magnetic type) around the middle section of the seat rail and glue/tape a magnet on the seat post. They should be positioned in a way that they passes each other closely and around the sensor mark (do not place the sensor too close to the front or back). Note that you may need to place the sensor vertically as oppose to horizontally when you installed on a bike.
      With that setup you will get a cadence number that is double of the strokes per minute.

    • hannahba

      Took a look at your FluidRower E-316 … nice.

      Mine is an old Kettler and as it is still working as it should (maintenance free) I am not willing to invest in a new one. Every stroke hits a little metal piece, which is then translated to an electric signal for the display. I had hoped to simulate that, but alas, did not work either.

      After everything else had failed I am currently doing this: I run Wahoo Fitness (Rowing) on my iPod4 (HRM is a Viiiiva) attached to the handle using a Breffo Spiderpodium and press on “Round” every 100 strokes.

      Afterwards, I use FitFileRepair tool to import the .tcx file, check/manipulate the data and export it to .hrm file which I can analyze in Polar PPP4 and Excel (have a separate file to calculate average cadence per round, etc. with some telling Charts).

      A lot of manual steps but that´s how it works for me.

    • hannahba

      @Sai To: Thanks for your comment.

      I have tried that and unfortunately, there are too many magnetic parts under the seat that keep pulling the magnet in all directions. Also, the seat is too far away from the rail. I would have to make changes to the seat and by doing so be adding weight. And, it would get difficult to get to the sensors if need be without taking the rower apart again.

    • Sai To

      What is the model of your rower?

    • hannahba

      @ Sai To: Pre 2004 Kettler Coach.

    • Sai To



      I did a quick test on my rower using a Wahoo cadence/speed sensor it seem to work, your rower may be a bit different but the concept is the same:

      link to saitosports.blogspot.ca

      Hope this help.

    • Sai To


      Found a problem with that Wahoo sensor, it will “wakeup” only when the speed sensor is being triggered. Not sure if a cadence only sensor exists.

    • hannahba

      Thanks for the explanation and the photos, that is a very good idea. Setting the wheel circumference was another problem I have had.

      Re. the doubled cadence: I will try to manipulate the data via the FitFileRepair tool, perhaps a simple Division across all records will do the trick.

      Cadence only sensors do exist (according to Ray), will look into that.

      Too bad I cannot test it right now as I am on a longer term project away from home but when I did test it, I will report back to you.

      Thanks again, Hannahba

      (I tried to reply to your blog but don´t have a corresponding profile to do so.)

  6. Urs

    Hi Rey
    Can the sensor be used on a Cervelo P3C? The P3C has a really small clearance between frame and crank. Just bought the Garmin GSC-10 and can’t mount on mine. :-/

    • I did all my testing on a P3C. 🙂

    • Ocelot

      Urs, depending on the cranks you’re using, i’ve had good luck mounting the magnet on the side rather than the back.

    • Bruce

      If the magnet is the clearance problem you can get round magnets that will stick to the inside of your pedal axle. I had to do this with my cross bike due to low clearance.

      Search amazon for pedal magnet and you’ll see some options.

    • Ted H

      magnet on the end of the pedal works great. I do that just so that I have a nice clean looking crank arm without a ziptie on it (for the garmin magnet).

  7. likepend1

    Hey Ray!

    thanks for the quick-look at the new magnetless sensors!
    One quick question: battery?? CR i assume (the speed sensor – pictures show that you can change it yourself, does this also apply to the cadence sensor?)

    • Johan

      On the Amazon page, it states “1 CR2 batteries required. (included)”. So giving it’s a CR2 battery, I would bet on it to be replaceable.

    • likepend1

      thx for the hint Johan, although CR2 batteries seem to be “pretty” big (in terms of the size of the sensor). think they ment coin cell sized ones.

  8. Rick

    Regarding the speed sensor, you say “…But really for most folks your GPS is going to override it anyway, …”

    Is this correct for the Garmin Edge line? My understanding at least up through the 800, was that the Edge first looked for a speed sensor and used that if found only defaulting back to GPS data if no speed sensor was found. Not the other way around. Can you clarify this?

    • Sorry, good catch. Here’s the overview of order of preference for GPS units:

      1. Power meter sending torque and cadence (e.g. Vector, SRM, Quarq)
      2. Cadence sensor
      3. Power meter sending power values and cadence (e.g. Power2Max, Rotor)

      1. Power meter sending torque and speed (e.g. PowerTap). In this case wheel speed is needed to compute power.
      2. Speed sensor
      3. GPS

    • Macrophotofly

      I have a powertap on my bike already. Do I really need any speed or cadence sensors in addition?
      I have the existing garmin magnet-based speed and cadence sensor on the bike (+ Garmin 800 as a headunit) and if it isn’t really needed then I’d be glad to remove it (and rely on the Powertap numbers if they are accurate).

    • Definitely not speed. And generally not cadence. In most cases the PowerTap is accurate for most folks for cadence.

      The areas it suffers a bit on are higher cadences (i.e. above ~150RPM), as well as sometimes the very brief transition period between going from a very high cadence to a lower cadence it’ll improperly register cadence. But that’s usually only a second or two.

    • Mr Nofish

      This comment:

      “But really for most folks would use GPS outside anyway, so it’s really just indoor training where you might be using some sort of app that utilizes speed.”

      struck me as odd. With some occasional exceptions, if someone in my Strava circle uses a Garmin they also use sensors the vast majority of the time. I think most average Joes just stick to a bike or maybe two and those get equipped with sensors and that’s it.

    • I guess my point there was that traditionally people bought the combo sensor mostly because they wanted cadence, and speed sorta came along with it. Now, you’ve got a choice (well, you always had a choice but they were off peoples radar). So, to that end, if you don’t use speed indoors on a trainer, then you’re likely better in most cases with GPS outside anyway.

    • Mr Nofish

      I see where you’re coming from, and it’s definitely possible things will change now that Garmin’s sensors have become separate, at least for those who never use a trainer.

      Then again, maybe I’m misunderstanding you, but I’d say GPS speed is more convenient, not better: as you showed in your posts, traditional speed sensors provide slightly more accurate speed/distance and cleaner data.

      IME, speed data from the sensor also has no drop-outs while GPS speed/position does (this, however, might be some bug in my Garmin’s firmware)

    • Ulrik

      Just to be clear – if the speed sensor is connected to the fenix3, GPS won’t be used to measure speed?

    • Paul S

      Yes, exactly. Speed/distance is computed from wheel rotations. The Fenix will still record GPS points, but won’t use them for speed/distance.

    • What happens when speed sensor disconnects for a while and I ‘m still running?
      Does the unit use GPS data instead?
      Generally, does it record GPS data at all? (and not show them if sensor available) ?

  9. Axcel

    How about forerunner 610, please?

  10. Rohan

    Hi Ray, any plans for some mountain biking comparisons? Garmin Connect shows my GSC10 cadence spiking to over 200RPM while i’m riding my trail bike, which I assume is the pedal bouncing around in front of the magnet (when not actually pedalling). I also expect that the magnets and sensors can get out of alignment when the rear suspension is moving around. I was hoping magnet-less would be an improvement for mountain biking – but it looks like you expect this would be worse?

    • It’s unlikely I’ll be able to show mountain biking, but if something comes up where I have the chance – I’ll definitely include it.

    • Ted H

      If you backpedal while mountain biking, which I do to get get ready to climb or move my pedals to prevent striking ground, stumps… you will get 200rpm cadence… the GSC10 sensor doesn’t know which direction you are pedaling, it just computes the time between one magnet contact to the next contact. But maybe the accelerometer based sensor is smarter? Simple test. bike to stop and then backpedal…

  11. I have used for a few weeks now. The comparison chart on the site shows difference’s between your chart.
    The fenix 2 is compatible. link to buy.garmin.com

    • Yup, I have the Fenix2 compatible above in my chart.

      The other items on their chart is incorrect, they’re incorrectly using the SPD/CAD combo sensor as the basis for their database pull. I tested many of them they said work, it simply doesn’t work with most older Forerunner units (i.e. FR60/70/305).

    • jetdog9

      Be aware that at this point (current software 4.40) the Fenix 2 uses zero average cadence and there is no setting to change to non-zero average cadence like there is with many other devices. Wherever they design/test these things, hills must not exist.

  12. Eli

    Is the firmware on the sensors updatable?

  13. tom

    This looks very clean imo. When using several bikes, the cadence sensor has a huge benefit on `old` models that work with tiewraps, right? Ray, you mention that you `won`t update all your bikes to new sensors` but in general you would only need one that you could swap between your bikes, right?

    • Definitely true. But, for me (personally), I like have the flexibility of having sensors on different bikes for testing. But yes, for most you could just move it around (though, there could/would be implications on that in the speed sensor wheel size configuration).

  14. Mayhem

    If Wahoo wanted to make a magnet-less speed only sensor, certainly they should be able to simply develop an alternate firmware package for the RPM hardware? Given that the firmware is user upgradable, selling more of same hardware and letting the users choose how to deploy it must make financial sense.

  15. Gert Jan

    What’s the benefit of using a speed sensor with edge 810 with GPS measured speed?

    • It would depend on your typical riding scenarios. It can be useful for mountain cyclists who may be in twisty terrain that doesn’t have good GPS coverage. Also useful for routes that have long tunnels or periods without GPS coverage.

  16. Doug

    Hi Ray,
    Is there any indication about changes to this sensor that might be addressing data dropouts from power meters such as Stages and Vector to certain units? e.g. dual sensor broadcast conflicting with power meter broadcast?

    • No, there’s no conflicting between sensors (never seen that in ANT+ between ANT+ sensors, though WiFi does seem to occasionally have impacts).

      For what I believe your addressing which is some (primarily) power meters that are crank based having issues with signal to the FR910XT for some people, I’m not sure if this will be a problem as well. I’m unable to replicate that issue with my setup, but it appears that it’s heavily dependent on position/frame/body/etc being blockers.

  17. Marc Michals

    Hi Ray… Thanks again. This is perfect for my dad’s Electra his crank arm was too far forward for the 800’s original sensor to work. He’s going to love it. Thanks again for all you do!!!!!!!!!!!!!!!!!

  18. Would that work with the Garmin Oregon series? The magnet-based sensors work.

    • It’s not so much due to being magnetless, as it is due to using the speed-only and cadence-only profiles.

      In looking at the ANT+ directory, it doesn’t list support, which matches my understanding that those units only have combo-sensor support. I don’t have those units on hand, so it’s hard for me to validate that.

    • Craig

      Yes, it probably won’t work. It seems the ‘outdoor’ Garmins (Etrex 30, Dakota 20, Oregon, Foretrex 401) only work with a combo sensor. But they ignore the speed data from the sensor, and always use GPS for speed.

      I have tested a Bontrager cadence sensor with a few of these, it didn’t work. Rather annoying, as the cadence only sensor is neater and cheaper than the combo sensor.

    • DanyRunner

      I purchase the Oregon 600, and disappointing enough it does not work. I never looked into this before I made the purchase but the free candence sensor is certainly NOT working. Why, why why???

    • I have a Oregon 600 and have been researching this. It appears the Oregon 600 will not work with the speed sensor, however, will work with the cadence sensor. There was a bug with some version of the Oregon software that caused it to not see the cadence sensors. Version 2.8-3.1 would not work. Older versions, 2.7, and newer versions will work.

      Mine has version 4.6. To find out, open Setup and then About.

    • I just got the magnet-less cadence sensor and it will not work with my Oregon 600. It kind of looks like there are no cadence sensor that will work with it.
      link to buy.garmin.com

    • Andrew Miller

      It looks like the Garmin Touch 35 is the only Garmin non-biking GPS to work with this. So now I have to decide whether to get the Oregon 600 and the older combined sensor, or a Touch 35 with this sensor…

    • danadam

      Both sensors work on my Oregon 600t with the latest (5.00) firmware.

    • Stefan

      I have not tested it, but from the garmin changelog:

      Changes made from version 4.80 to 4.90:
      Added support for Bike Speed Sensor
      Added support for Bike Cadence Sensor
      Fixed issue with saved track stats precision

  19. pete

    How does the speed sensor work?
    If it just measures RPM how does it know your wheel size – is what programmable somehow? Or does it have to be paired with a GPS unit so it can calibrate itself from that – in which case what’s the point if you already have a speed measuring device on the bike?

    • Adam R

      You can input a wheel size on the GPS device, or some auto-calibrate based on GPS at the start of the ride. The benefit is more accurate distance where there is poor GPS reception, or where there are frequent switchback turns. It also (in my experience) gives much more up-to-date speed. Using GPS for speed is very slow to show accelerations and decelerations.

  20. Adam R

    Thanks for the info Ray.
    Can you tell us how much the sensors weigh. I am contemplating changing my gsc-10 for the speed sensor (use Vectors, so I don’t need the cadence part), but there is little point if the weight is the same.
    I have been reluctant to go without a speed sensor because I have found GPS instant speed very slow to respond to actual speed changes, and I worry (foolishly) about the two times a year or so I go through a long tunnel.

  21. Paul Reed

    Thanks for all the info, Ray. Great job, as usual.

    Don’t know anything about the tech in this device. Any limitations regarding wheel choice? (i.e. Carbon discs.)

    • On a disk wheel, it would come down a little bit to whether there was space on the hub to wrap the rubber band portion of the sensor around. Most discs wouldn’t have that space unfortunately.

    • Hefin

      Would be interested to know if this would still measure wheel speed if taped to the side of a solid disc wheel. Could file down the hook on the case and pop it into the valve hole area on my Corima disc.

  22. Pilot

    FWIW. These sensors work by detecting the direction of gravity going around in a circle as the wheel or crank rotates. No gravity = no cadence or speed, which is not likely a problem, but an upshot is they won’t detect cadence or wheel rotations while catching air, or riding your trainer on the ISS.

    • Patrick Myers

      Thank you!! As a professional BMX vert rider that does a little astronauting on the side, these are important things I hadn’t considered. I guess I’ll stick to the GSC-10.

  23. Dom

    Any idea yet whether the Forerunner 620’s bike mode is likely to support these? (Or, indeed, any speed/cadence sensor?)

    • They’ve confirmed yesterday that the FR620 bike mode update is still on track for this spring, and they’re getting me detailed implementation information by the middle of next week. As part of that I should have clarity on which sensor types they’re supporting. Previously they committed to feature parity with the FR610 bike mode. But, I’d be surprised if they didn’t support the new sensors. We’ll see…

    • No bike mode for FR220, I assume? 🙁

    • Correct, that’s currently my understanding.

    • Roger

      i’m waiting the 620 improvement (the newest firmware 2.7 doesn’t allow the compatibility)… and i’m waiting to buy the speed/cadence sensor. it is delaying very much!

      If I had known the release of Edge 1000, I had not bought the Forerruner 620.

  24. Nicholas Fournier

    So, a quick tangential question about the data that Garmin displays. Since I have a powertap, does the above suggest that the powertap speed data is what gets displayed on a Garmin 500? As for cadence, does that come from the powertap or the GSC-10 (the powertap estimates cadence, but doesn’t seem to do so all that well).


    • Tim

      My Edge 500 seems to use the GSC-10 for Cadence when it’s present, only falls back to PowerTap cadence when the GSC-10 is missing.

      In fact I just noted this last night as I forgot to switch my bike profile for my ride. Man that PowerTap cadence data is jumpy and inaccurate at times (compared to GSC-10 at least)!

    • Correct, with a PowerTap your speed data would come from the PT. Whereas your cadence data would come from the GSC-10 (because PT cadence data is considered less trusted than the individual sensor).

  25. Turn The Damn Cranks

    The old school Garmin combo sensor is a problem on my mountain bike because it picks up speed but not cadence, no matter how I tweak the set-up. I use an Edge 500 to capture the data. Can I keep using it for speed while also using the new cadence sensor? In other words, will the Edge 500 read both the combo sensor and the cadence-only sensor at the same time?


  26. I think you may me missing one point in the recs on the speed sensor. While it does appear to be slightly less accurate than the traditional one, it remains vastly more accurate to having a speed sensor that gets ever so slightly bumped during a ride and ends up happily recording zeros. That doesn’t happen to me very often but it does happen, and its a real PITA when it does especially since my non-GPS head unit (I keep a $99 cycleops on the bike for an easy long-battery readout while using my 910XT to record) will shut itself down if it thinks you’re not moving, losing my cadence and HR displays.

    Great review as always; I think I’ll take your recommendation and wait a month or so but I’m definitely grabbing a pair of magnetless sensors before IMUK this summer.

    • Don’t know why I feel compelled to edit, but I realized that the PowerTap Joule hasn’t been CycleOps branded in a while now. Old habits die hard I guess.

    • Yup, absolutely on not getting knocked. One of the things I really love about The Girl’s Duotrap setup in her Speed Concept.

    • I have to second the duotrap. I had the gsc-10 on my road bike but since I moved to a Madone and shelled out the cash for what I think should be an included sensor I’ve had zero drop outs. I don’t know if it’s patented but seriously a good idea that others should copy.

    • Karl BIlleter

      This happened to me yesterday . My speed sensor had slipped without me noticing for a while. Went for a climb in national park with a couple of 20% pinches and I was “stopped” for a minute or two. I guess it was too slow for sketchy GPS reception. Also couldn’t hit start and keep climbing 🙂

  27. Christian Glupker

    This past week somebody stole my GS10 Garmin sensor off my mountain bike. They even took the crank magnet and wheel magnet. They just left cut zip ties. With these new items I wouldn’t leave them attached all the time. However it does sound like they are easy to install so maybe not a big deal.

  28. Randy

    Your second chart – the one with links to product pages – seems to have some issues with the column headings.

    Any idea what kind of battery life we’re looking at? Are these things constantly broadcasting?

  29. Mark

    In the two graphs comparing the magnet-less cadence sensor with Vector and the Bontrager sensor, it’s curious that there is any difference at all between the magnet-less sensor and Vector. I would have thought (incorrectly, as it turns out) that they both use exactly the same technology to measure cadence.

  30. Rob

    Disappointing my FR70 won’t support these. Nothing more irritating as having to get off the bike and adjust the sensor because I knocked it.

  31. David

    I like how clean the setup is. With my current magnet based Garmin setup the physical structure of the crank arm makes it hard to get a precise alignment with the magnet and while it works 95% of the time on occasion things get skewed (in particular if I trail riding) and I have to adjust it. This would seem to solve anything and I agree, the .4-.9% variations and lag are unnoticeable and meaningless when riding outdoors with a GPS based unit to measure total distance, I can only see the higher “error” of the magnet-less units being an issue when needing (but do you really?) exact distance on an indoor trainer.

    I like it.

  32. MAGNUS

    Good read thanks for the info… I just got into Tri, and still fairly new to running, and I wish I had found your site before buying most of my gear/tech. At the end of the day, what I bought works for me just fine, and I’m happy. Just wish I had put more thought into researching what was available, or on the horizon, before buying something.

    Again, thanks. Great site.

  33. Sean

    Can you post how much the speed sensor weighs? I would like to do away with my GSC-10 since I have a Quarq, and I don’t really care for the look of the magnet mounted on the spoke, nor the GSC-10’s vulnerability to getting knocked by my foot.

  34. Zen

    Thank you Ray for the excellent review! I’d like to get this new sensor for my indoor spinning bike (link to amazon.com) do you know if the speed sensor can be installed securely on the wheel? If the sensor isn’t too large, maybe I can attach it?

    • That’d be tight. Looking at the up-close photo of the wheel hub, I think it might sit semi-lopsided – and be prone to sliding off. Could actually hold, but really hard to say when you get it up to full speed.

  35. wayne

    Are the batteries user replaceable? What type of batteries are used?

    Thanks for all the work Ray!

    • They use standard CR2032 coin cell batteries. You can replace them, and the batteries normally cost about $2-3 in the US (or far less if you buy packs online). On average it’ll last about 1-2 years.

  36. The bumping thing has been pointed out, but I’d also add that especially when riding the mountain bike, a GSC-10 can be bumped to an even WORSE state than losing data. How can that be? Simple. To me, if you bump one so much that you get no pings and it shuts things off, at least you’re likely to notice it shut it off and can fix it. However, a Garmin Edge 800 won’t shut off, it will simply switch to GPS data only in that case. For a mountain biker, that could be worse since I’d rather notice and fix than get bad data, which is what’s going to happen. Or there’s an even worse scenario possible. If a GSC-10 gets bumped where it only OCCASIONALLY gets the ping instead of every wheel revolution, you’ll get VERY bad data. And you may not notice it’s happening depending on what fields on your head unit you are paying attention to.

    I’ve had this happen. Folks have hacked some tools to help strip out bad sensor data and recalculate things based on the GPS data alone, but it’s hacky and doesn’t get you 100% valid data again. And it’s a pain to do.

    Two things for Ray: First, maybe I missed it, but any mention of battery life on these new sensors compared to a GSC-10? Or any alert when batteries are failing or have failed other than the sensor going dark?

    Second, I’ve made the offer before, but if you want an official reviewer for MTB specific things, I’m willing. I have the capability to log multiple sets of sensors on a single ride (own an Edge 800, 810, Fenix2, 620, 310XT, …). I ride multiple times per week, too.

    I would LOVE to move to a setup like this instead of the more fragile GSC-10, but I fear the current firmware state and bumpiness of MTB may throw the data off too much. Wouldn’t mind testing it if results were going to get published, though. I’m happy to use the same criteria of “test the free stuff, return and buy my own”, too.


  37. Ben

    I love your prudence with endorsements. I ordered this from Clever Training. It’s a *no brainer.*

    I’m sick of readjusting the speed sensor on my chain stay after rough car rides, I hate the big ugly, filthy, black thing on my chain stay. I hate really tightening something up on the spokes of my pricey carbon wheels.

    I can’t WAIT to clip off those stupid zip ties and install this speed sensor. Garmin has hired a smart person; their mounting ingenuity is awesome and improving the whole industry.

  38. And of course the battery question is mostly answered in a post while I was typing. Still wondering if we’ll ever get any kind of alert that sensor batteries are dying before it actually happens…


    • Hmm, not sure if it sends a battery alert. Many other devices do (i.e. power meters).

    • Vincent Ludenhoff

      Yep it does. My Edge 1000 gives me a notification on the sensor battery level running empty. I did an other 250K on the old battery, after receiving the first notification. No problem. So plenty of time to score an new battery.

  39. Bayron

    Have you heard if this is gonna be compatible with fr620?

  40. Robin

    Ray, according to the email I got from Garmin Support, the new sensors should work together on the 705. Has Garmin told you differently?

    • I tried it on Sunday, no luck. It only knows of combo sensors. ANT+ database confirms that. Fairly certain my unit is/was up to date.

    • Jeff

      It’s amazing, the box and online literature all claim it will work with the 705. I have the latest firmware on my 705 but it will NOT pair either a speed or cadence sensor.

  41. Fred

    Greetings Ray,

    Could you please check links for this item in your table:
    Garmin Speed & Cadence ANT+ Sensor bundle (magnet-less)
    I get two 404s and one link that works but seemingly goes to the wrong product.

    Thank you!

    • Ahh, weird. Well, those ‘More info’ links basically just point back to this page (‘More Info’ links in all charts simply point to my most relevant post on the subject). All fixed now!

  42. Swuzz

    Hi – Just wondering if these might wotk with an iBike Newton?
    I have one extra user profile available if I get an extra speed/cadence set for it.

    • I think it does, since both the earlier gen iBike’s support speed-only and cadence-only sensors, I’d be really surprised if they removed that feature in the Newton (travelling at the moment so can’t check on my unit for certain).

  43. trickycoolj

    This would have been a perfect solution for me on last year’s Seattle to Portland. My speed magnet decided to not work in the parking lot at the start line and the entire first day’s century I only had cadence and no speed/distance! Of course I have also since upgraded to a Garmin 500 from the Bontrager Node so at least now I’ll have GPS data as a fallback for this year’s STP.

  44. Tobias

    Wow, thanks a lot for this pretty cool description. As I have a 310XT my question from the very beginning of your Text was: “will it fit to my FR??” and thanks to the great table you made, I got my answer 🙂
    Thanks a lot!

    Greetings from Hamburg

  45. Anders Majland

    I have the GSC-10 on my road and mtb and the bontrager combo on the bmx. Both the mtb and bmx sensors get knocked out of position. So I’ve now ordered the magnet-less and will try it on the bmx first since that is where i have the most issues.

    Ordered it from Clever Training trough ebay because of easier custom handling to Europe. A direct parcel would add a $30 fee to the post for handling Customs and VAT. So no discount for me and no kickback to the site on this one. Could’nt find it on Amazon.de or Amazon.co.uk

    Well let you know how it works in a bumpy environment – i.e bmx track 🙂

  46. BartW

    I read the article yesterday and found it strange a difference in (total) distance occurred. Thinking about it tonight i would really be interested on how this can happen with modern electronics with use (i think) the newest MEMS sensor IC’s.
    I can’t imagine the new speed sensor counts the rotation false. It is very easy to make a hysteresis based on an 360 degree angle so the number or rotations can be counted 100% correct. (No wheel bump creates a 90 degree rotation or anything near)(this sensor could even give multiple pulses per wheel rotation if needed).
    So next remains the software, if it uses the rpm of the new sensor (which has much more noise) and directly calculates the distance and rounds it in a too low resolution this things can happen and can be corrected by software.
    So i’m very interested if the error is in the sensor itself (magnetic sensor pulses rotation sensor) or the registration unit (rounding errors).

    • Paul S

      As Ray pointed out, it could also be calibration error, having the wrong wheel circumference, since he took the data on two separate units. So I wouldn’t sweat one test. Still hoping for the email from CT soon, and then I’ll be able to do my own tests. (They really should have had some way to join earlier pre orders to our VIP accounts 🙂 )

  47. adam lewis

    I wonder if there is some over smoothing going on with the magnet like sensors that we have all become accustomed to? The current set of sensors have no info of what happens in between the magnet passing and the next pass. Of course at speeds this is a fraction of a second but when coming to a quick stop the sensor has to somehow decide how long to wait until it confirms that the wheel is no longer moving. Thus it needs some smoothing / lag effect.

    I read the details on a kickstarter version of this which in essence said the sensor measures movement and so can measure speed (or movement) at any point of the wheel turn. Thus it can be 100% sure the exact moment the speed is zero. Again as you say I think the rpm is only broadcast at once per second but could there be an increase in accuracy in the new sensor that is creating the ‘noise’ possibly as a result of only being able to publish this ‘more accurate’ speed once per second?

    • Taeho Jang

      Interesting idea. What if the new sensors were tested in constant speed? Would there still be ‘rumbling’?

    • In most cases for my trainer workouts I’m applying a constant power and a constant cadence, as a result – the speed for usually upwards of 5-minute sections is constant.

      Garmin has an interesting theory they sent over tonight that they think the PowerTap hub electronics/magnet may be interfering with speed sensor a little bit causing the noise I see. So, I’ll give it a shot when I return for this weekend and see what happens on a regular wheel (or, just my front wheel).

    • Hi Ray, I know I’m digging up an old thread here, but is there a consensus on how a Powertap hub affects the speed sensor? Should I just put it on the front wheel to be safe? I’ve got one in the mail, and it’ll be going on a PT wheel, since my old GSC-10 died!

  48. Patrick Brochu

    Thanks for the review Ray, as always it is really helpful. What is the width of the speed sensor? Trying to figure out if it will work on my disc wheels.

  49. Rob

    I know the matrix shows the FR60 and FR70 as only supporting combo sensors, but the GARMIN page for the new sensors shows the FR60 and FR70 as compatible. Also their FR70 page shows the new sensors as an applicable accessory?

    But then again, It also shows the FR305, FR410, FR610, and Edge 705, so clearly Garmin doesn’t understand their own offerings…

    • They’re wrong. Simple as that. I’ll bring it to their attention to get corrected. I suspect it’s just a case of them accidentally tagging “Speed/Cadence Combo Compatible” instead of Speed-only and Cadence-only compatible.

    • Rob

      Hi Ray,

      I don’t want to continue to harp on about low end, outdated equipment, but I still like my FR70….so, not sure if you’ve brought this up with Garmin yet, but even when I contact them directly I am get conflicting answers.

      When I first contacted them to ask, they said no it won’t work, and no they don’t plan on releasing new software. When I asked why their own web page lists support, mainly as a courtesy to them so they don’t have to process returns, they responded again saying sorry we were wrong, the FR70 does support the new sensors, no software upgrade is required.

      They then continued to provide me step by step instructions on how to get it working, but its the standard instructions, nothing new or special.

      Is the 310XT the cheapest option that does support individual speed and cadence sensors?


    • Yeah, I’ve brought it up as well. No idea why it’s taking them this long to fix the site.

      As for cheapest option, yup, the FR310XT would be it.

  50. Keith

    Will the speed sensor hold on a Chris King r45 rear hub with non-uniform diameter?

    • I don’t know there to be honest.

    • Scott

      It holds, just tried it, even though I’m using it for my front Chris King hub. Garmin’s product documentation even mentions asymmetrical hubs.

    • Ted W

      Asymmetrical Hubs. I was just looking at getting this, and I believe that perhaps rear wheel is asymmetrical. THought to be honest, I never heard that phrase until today, and never even notice my axle on my rear tire. Its thinner in diametert on one side an in smoothed/rounded sort of what, it get larger in diameter as it gets closer to the rear sprockets. (forgive my lack of technical bike lingo). I have alx320 on the rear. Found a picture that shows it. Would the speed sensor work on this. is this what garmin considers asymmetrical
      link to img27.olx.pl

    • Justin

      hey keith/ted- i’ve been using the speed sensor on my rear r45 for ~6 months. been totally fine, but looks a bit funky off-centered on the rear hub. based on the other comments, i’m just moving it to the front hub.

    • Ted W

      On my training the speed sensor has worked fine. I dont recall seeing other comment. If I were to use it on the road, I dont see an issue with moving it to the front, unless the rubber bandwas stretched. for now, on the training, its find on the back, and of course it needs to be there for a trainer

  51. Darwin

    My local REI has the cadence sensor in stock.

  52. Mr Nofish

    Thanks for the post, I was mildly excited about these new sensors, not sure I still am now: it’s nice that they can’t be bumped out of position like traditional ones (but that’s rare on my road bikes, plus my Edge 500 does not turn this into a bigger deal than necessary), there’s no clutter on the chainstay and they’re more portable, but I’m not sure the positives exceed the negatives, at least for me.

    On a sidenote, this sentence:

    “From there you’re apply it to the non-drive side of the crank arm (that’s the side without your gears).”

    the way you wanted it to write, I suppose was: “From there you apply it to the non-drive side crank-arm (or maybe:) the non-drive side of the crankset”

    The real problem however is that IMO it is overcomplicated in a bad way: if you think there’s people reading who won’t know exactly what the non-drive side of the crankset might be, why not avoid that?

    IMO the part between parentheses feels a little condescending, like you’re taking a slight pause to talk to a slow child. Why not simply say the left crankarm ? I don’t think there’s many singles out there where the drivetrain is not on the right side, it’s short and anybody should be able to understand, regardless of their level.

    • Because I learned the hard way in my original Stages power meter posts that people don’t know which side the “left crank arm” is. Folks ask: Is that the side when on the bike, or facing the bike?

      Thus, by including the piece in the parenthesis, it makes it really clear it’s the side without the gears. The common terminology is always drive-side and non-drive side. I did the parenthesis specifically because of past learning’s and to simplify. But, since I write for all manner of people at both ends of the spectrum, I try and keep it as clear cut as possible while taking into account having to re-answer questions approximately 28.5 times on each review post for questions I would have once thought were obvious. 😉

    • Mr Nofish

      Hrmmm I guess that might explain the stupid amount of salmoning I am confronted with every day… But I’ve got an easy fix, just ignore them and concentrate on something more productive than explaining 28 times and a half which side of any vehicle is the left one!

      I’m sure other commenters can take care of it: not exactly a question you need to have a Stages PM (or whatever sensor) on hand to answer 😉

      (PS: don’t forget to fix the sentence)

    • Jim

      And while I usually know something like what the drive and non-drive sides are, I absolutely appreciate Ray just making it crystal clear!

  53. dECEIT70

    I just lost the magnet that was glued and zip-tied (!) to my left crank-arm,… err… to my non-drive side,… err… you get the idea.

    I know buying a new magnet would be cheaper, but since i’m not really using the speed infos from my GSC-10 combo, and i find it to be and ugly thing on my beautiful TT bike and Zipp wheel, i’ll consider buying the magnetless one…

    I’ll have to check if that fits on my crank… (you know? The left-sided one… when on the bike…)

  54. Stuart Brown

    As a non-head unit user recording all my rides on my iPhone, I have a Wahoo Blue SC. I’m holding on for a cheaper (less than Edge 810 money) head unit that works with all my Bluetooth smart sensors.

    My big issue with the Blue SC is the crank magnet is so damn hard to get on and off a crank (especially since BB troubles have meant lots of crank swapping and the Blue SC unit itself is not stable on my very rounded chain stays and frequently gets knocked.

    Obviously my iPhone records speed via GPs in lieu of a computer with GPS (so I would have one of the two). Are there any BT cadence sensors that mount like the Garmin? I really like the flexibility of the mounting, I don’t really like the zip tie mounting of the Wahoo RPM which has put me off buying on. Are there any other options?

    • Yeah, definitely go with the rare earth magnets. It’s what I use on some of my bikes where I don’t have Vector installed. Zero problems, increda-cheap.

  55. n8udd

    Hi Ray,

    With my current GSC10 I quite frequently get spikes when coasting down hill (where the magnet sits along side the sensor).

    If the new cadence sensor works on accelerometers, I’m guessing that it should eliminate this issue?

  56. I love the thought of using this with my Fenix2 when I’m on the road and just have a spin bike available to me. Obviously I wouldn’t be able to get speed data still but to have some sort of metric would be great and cadence is probably more important anyway. I might wait for Wahoo if only because I can see myself forgetting this on the bike and would rather have it on my shoe.

  57. AAG


    A couple of questions regarding the Wahoo RPM. Do you know if they will be keeping the form factor the same? I recently purchased one to stick in my sock when riding a stationary or doing a spin class. No need for the ANT+, but the firmware update and the shoe mount could be attractive.

    It would be terrific to see Wahoo launch a dual band stride sensor. I feel a little self conscience right now with my ANT+ one one one shoe and Speed_cell on the other.

  58. Ken G


    “While we’re at it, Wahoo does still have plans for an updated Blue SC Speed/Cadence combo sensor later in the year (dual-ANT+/BLE), and are determining whether there will be enough demand for a speed-only model as well. ”

    How can I register my interest in a separate Wahoo speed sensor? As a non-traditional bike rider (Rans V-Rex recumbent), the combo SC sensors don’t cut it for me…



  59. Adam

    Could the hub-based speed sensor address the funky speed computation on the KICKR/GSC-10/TrainerRoad/Strava combination? To be clear, i’m not sure whether the speed inflation is from the GSC-10 given there is no backwheel, the KICKR, TrainerRoad, or Strava when you upload the trainer TCX file.

    • Hmm, I’m not sure to be honest. I haven’t uploaded any files from TR to Strava. :-/

    • Adam

      so according to the TrainerRoad guys, the KICKR speed data isn’t useful in ERG mode. I’m looking into whether i can strip it when i upload to Strava. I use Strava as my data hub.

  60. Your photo shows the speed sensor on the rear hub, any reason it couldn’t be on the front hub? I live in Southern California and never need to ride my bike on the trainer. 🙂

  61. JeromeC

    The cadence sensor, do you think it would work on spinning bikes if it was tied to a shoe the same way as a Garmin running pod? In other words, could one walk in and out of a spinning class carrying is/her own sensor?

    • Hmm, not sure. I’ll give it a shot.

    • Ted H

      Unless there is a clearance issue between the crank arms the spinner bike frame, you could just strap the cadence sensor on the spinner bike… just don’t forget to take it with you afterwards…

    • as

      Did you ever try the Garmin cadence sensor in a spin class? I would love to get that vs. the Wahoo, for a number of reasons, but I am curious to see whether it would actually work.

  62. JagadeeshP

    Will this work with Garmin Forerunner 610? I saw the answer to a previous question that said no. So I suspect the data given at the Garmin webpage on “Compatible Devices” tab is incorrect. Is that so?

    • Correct, it will not. The Garmin page is incorrect.

    • Filipe

      Hi, I just bought this on amazon, I received exactly what you have in the first picture of the page, the three bands and two sensors, and I can´t pair it with my Forerunner 610… anyone already went through this problem and can help me before I sell this to buy a GSC 10? Thanks…

    • No, there’s no method to get it to work with the FR610. It’s not compatible there (see the compatibility table in this post).

  63. Antonyb

    DCRainmaker your are the only source of truth !!!
    A getting to the new sensors and looking at the charts above I still cannot tell if my garmin 800 will work it’s both speed and cadence sensors at the same time.

    The chart impels it’s one or the other but not both at the same time. ?? Only the 1000 will do that. ?

    Is that correct ?

    In which case is there a work around or does this mean that only one sensor is worth buying ? I cannot work put how to auto detect the different sensors.

    Thanks in advance t

    • Yup, that’s correct. I had updated the ‘only one at a time piece’ a few days ago as I noticed it myself when I went to try and pair both. The challenge is that the older units only allow you to pair ‘one’ of that category (speed/cadence/combo sensors).

      I think whether it’s worth buying comes down to whether or not you’ll use speed and cadence indoors. If not, I’d hold off until other combo sensors come out.

    • Paul S

      My speed and cadence combo arrived from Clever Training today. I had a little trouble getting the speed sensor on my Cannondale Lefty front hub, but I did finally manage to reach through the spokes and stretch it enough to catch the latch. Otherwise, installation was uneventful, except I was never able to find the LED that’s supposed to be on the cadence sensor and is suppose to light when it starts. The LED on the speed sensor was obvious.

      I can confirm that both sensors will pair, at the same time, with an Edge 800. It took a little “button” pressing (the UI is not obvious), but I eventually found the “Speed and Cadence” button, and both paired after I found it. I was wearing my Fenix 1 so I tried that with no luck. It wouldn’t pair with the cadence sensor (didn’t try the speed).

      So my first actual ride with it will be Thursday or Friday (depending on how much rain we get in the next two days, I may want to let the mountains dry out for another day). I’ll let you know…

    • Mark

      Paul, can you please explain in detail how you managed to connect both? I’ve an 800 since last year and it doesn’t allow me to connect the two at once neither seperate.

      Thanks in advance!

    • Paul S

      I’m not sure I can, since they’re connected now and the “buttons” have changed. It went something like choose the bike profile, select ANT+ Speed/Cadence, select Bike Sensors and choose “Yes”. It didn’t connect at that point, since it was looking for a combo sensor, but I think that a “Sensor Details” button appeared at that point. Selecting it gave me a choice, one of which was “Speed and Cadence” (note, not “Speed/Cadence”). Then I could pair each sensor individually. Both worked at that point, I could see the cadence in the cadence field, and a much-too-high speed in the speed field (because the default wheel circumference is 18 meters for some reason).

      I haven’t yet actually used them. It was too wet today (I got rained on during my road bike ride this morning). Tomorrow the 6th stage of the Trans-Sylvania Epic occurs in my neck of the woods, but I may still go because I can probably manage to avoid their course (which they put online), at least when they’re going to be there. If not, first use will be this weekend.

    • What Paul described is correct. The key is “Speed and Cadence” vs “Speed/Cadence”. The second is the old-school combo sensors, versus the newer separated sensors.

    • Mr Nofish

      FTR I just checked on Edge 500 running v3.3 and there is a “Speed and Cadence Sensor” menu entry that lets you pair two sensors (two ID boxes) unlike “Spd/Cad”.

      So it was all just a misunderstanding?

    • Yes, as long as there is a separate entry for that, then you’re good. Or, in the case of the FR910XT, you can select multiple check-boxes. Whereas some older Garmin units won’t allow you to.

    • Paul S

      Here is the track as collected by the Edge 800, and, for reference, here is the track recorded by my Fenix, with GPS speed/distance (3D on, WAAS on).

      The only glitch occurred at the beginning. On Tuesday I had put in a manual calibration number (2070 mm) that was much closer to being correct for a 26×2.1 mountain bike tire than the 18000 mm that the Edge defaulted to, but then I told it automatically calibrate. So naturally for the first km it used 18000 mm (so I had a spike of 79 mph), so it overestimated distance/average speed/etc. Once it auto calibrated (to 2060 mm) it behaved very well. It also seems to have dropped the cadence reading for the first minute. I’ll have to check my VIRB video later to see if it’s also missing the cadence for the first minute.

      The big difference from using GPS speed was on the climbs. Usually my 800 on a climb would wobble back and forth +/- 2 mph around the correct value at slow speeds, so it was not very useful. With the sensor, it was very steady, closely tracking the speed shown by my CatEye with the usual magnetic sensor. The speed graph looks good; most of those little spikes are real. One other thing I’m going to watch for is that I don’t remember ever not seeing a number in the grade field. A bug/feature of the 800 is that for too low speeds (and I’m very good at going that slow), it won’t compute a value for the grade. I don’t know why a speed/distance sensor would change that, but maybe it does.

      Anyway, the first use, aside from the calibration glitch, seems to have gone well.

  64. KiwiGirl

    Hi. I’m after a cadence sensor for my spin bike and this looks just perfect. Are they for sale yet and, if not, do you know when they are expected to be?

    • They’re available today, and have been out in the market for about a month.

    • KiwiGirl

      Thanks for that. I’ve searched and searched online and I can’t find them available anywhere. Do you know anywhere that sells them online? I’m in NZ and I can’t find one locally.
      Thanks so much!

  65. Carlo

    Hi Ray,

    I was thinking about buying EDGE 810 + new magnetless sensor, because I don’t exactly like the older GSC-10 combo sensor. I read the issue of speed inaccuracy (which could be caused by some “interferences”), but I also read your final statement:

    “With all Garmins that do support the speed-only or cadence-only sensors, you’re only able to concurrently connect to EITHER the speed-only sensor or the cadence-only sensor (or a combo sensor). You can’t connect to both the speed-only and cadence-only sensor on Garmin units (except the Edge 1000). Basically, the pairing menu only allows you to connect to one sensor in that category (again, except the Edge 1000).”

    Do you think that with a software update also the 810 will have the possibility to connect to both the speed-only and the cadence-only sensors?

    Thank you very much for your answer.

    Your reviews are great.

    • I’ve confirmed the 810 does actually have said capability today. You just need to scroll down a bit more in the menu to choose ‘Speed and Cadence sensors’ and it’ll allow you to pair them separately. Enjoy!

  66. Mr Nofish

    I would hope this capability gets added to old models as well, epecially since they’re still being sold.

    Unless there’s some obscure limitation I’m missing here? even though the vast majority uses a combo sensor, I can’t see any reason why someone couldn’t end up with two separate sensors of the traditional variety.

  67. Carlo

    Ciao Ray,

    I like novelties (like the new speed / cadence sensors) but I do like more accuracy.

    In this sense, do you confirm your statement: “If you want super-high accuracy – go with the magnet?”



    • Carlo

      Hi Ray,

      can you confirm that If you want super-high accuracy – the magnet is the best choice?



    • Paul S

      What do you mean by “super high accuracy”? These things count rotations, so there’s a natural minimum of about 2 meters (circumference of the wheel) for the accuracy they can obtain. After that, it’s all a matter of how well they count rotations. The reed switches in the magnetic sensors are old technology, so they probably do a good job, but I don’t know if even Ray 🙂 has actually tested how well they do. So probably the magnetic sensors will count more accurately, but that remains to be seen. (And if the magnet gets knocked out of alignment, which one is going to do a better job then?) In either case, you don’t use them for surveying.

      And does the difference between, say 25.7 miles and 25.93 miles (numbers taken from my Sunday mountain bike ride) really matter to you? It doesn’t to me, it was the same ride no matter what the sensors say.

    • In general, I’d be fine recommending the sensor for anyone who’s not doing aerodynamic testing ala what I noted above.

      Some of the variation I was initially seeing does indeed seem to be related to the PowerTap wheel. But I’ve got a bunch of tests I’m doing this weekend to 100% validate that.

    • Mr Nofish

      I’m waiting for Ray’s tests but the charts he’s posted so far would seem to indicate that while the accelerometer sensors might have a comparable accuracy to traditional ones, they’re not as precise.

      If that turns out to be the case, then there’s another scenario where traditional sensors might be better: on a trainer, trying to keeping your speed constant (e.g. virtual power) is easier if speed isn’t jumping all over the place because of the sensor.

    • Paul S

      Yeah, but on a trainer there shouldn’t be any extra accelerations, so the accelerometer based sensor should be very precise. I realized that under ideal conditions the new sensor might be able to do better than a magnetic sensor since it should be able to detect fractions of a revolution, unlike a magnetic sensor. (But I have no idea what algorithm they’re using, so it may not be able to work like that.)

      The normal case, though, of a sensor attached to a hub that’s getting all sorts of extra accelerations from the road (and in the case of a mountain bike, that’s on the wrong side of the suspension) is the real test. Looking at the output of the accelerometer in my VIRB during mountain bike rides was a real eye opener, and that’s on the soft side of the suspension.

  68. Cleve Waterman

    I have one Edge 1000 for two different bikes. The second set of magnet-less speed&cadence sensors is in the mail. Will I have to create another “Activity Profile” for the second bike or can I just have two speed and two cadence sensors on one Activity Profile?

    • Cleve Waterman

      I was wrong. The sensors are connected independent of the Activity Profile. I hope I can have multiple speed and cadence sensors assigned to one Edge 1000, otherwise switching bikes will be a pain.

    • Yes, you can have multiple bikes worth of sensors paired in the Edge 1000. I have…uhhh…a lot of sensors paired right now (probably about 5-6 bikes worth if you were to evenly divide them up).

  69. Sorry if dumb question – new to GPS (currently using PowerTap and normal yellow CPU for power/speed/cadence etc). Looking to upgrade bike and hence all other bits.
    If I go Vector Pedals and Garmin 1000 – do I still need a speed sensor or is this covered off in the Vector Pedal (as I assume the cadence is as well).
    PS: thanks for all your testing and reviews it has helped me greatly in spec’ing up my new build.
    Baum Cubano / Enve 3.4 (CK R45’s) / Enve Post, Stem, 2.0 Forks / Record / Garmin Vector / Garmin 1000

    • With the Edge 1000 and Vector, you don’t need any sensors while outdoors. Cadence will come from Vector, and speed will come from GPS.

      It’s only if you wanted speed indoors that you’d want some sort of separate speed-only sensor.

    • But how accurate is speed from GPS – i.e. looking at say a 12 sec sprint (I do lots of crits) – on the power tap I can get every second – thoughts ???

    • 12-seconds you should be fine with GPS for a sprint. You’ll see slight lag in the first couple of seconds but then it typically evens out. Ultimately, it won’t be as precise for instant feedback as a separate sensor, but you can try it out first and then add a sensor later if need be.

  70. Raul

    Hi Ray, the preference orders were new to me. I’ve always thought the sensor values were not used until GPS was down.
    Resumé pour le velo: even when the PT wheel is in my bike the Edge will report the GSC-10’s cadence value?
    And the speed comes from the PT and with another wheel from the GSC-10?
    Funny thing: the wheel size is calculated from GPS measuring! Looks like a circle!
    I had a look at my indoortrainings and the speeds are quite low, at least 5 k slower than outside!

    On the 310XT I think I thought (?) that the ‘GPS’ setting was to instruct the device on how to calibrate the pod……..

  71. Anne Raduns

    Can you tell me if I can use the magnet-less cadence sensor with a Stages power meter crank arm. I have the Dura-Ace 9000 left crank arm. There doesn’t look like there is enough room from the end of the compartment to the end of the crank to put the sensor. So, I would have to strap it on to the compartment area. Will this effect the stages meter? Any insight would be appreciated.

    • You should have enough space to put it between the compartment and the portion of the crank that connects to your bike. But, I’m travelling at the moment and can’t verify that 100%. Plus, there is a small factor that depends on your specific bike frame and having enough clearance that close to the bike frame.

    • Mark

      If you have a Stages power meter, then you don’t need a separate cadence sensor at all. The Stages power meter provides the cadence measurement.
      link to stagescycling.com

    • Scott

      Mark: you do if you’re using something like the Powerbeam Pro which you’d use for power and speed. Stages sends cadence as part of the power data but it doesn’t send it separately as a cadence only profile so when using something like Virtual Training on the iPad or a computer, you get no cadence.

      Anne: I just mounted the cadence sensor to my Cannondale Hollowgram with Stages arm and it fits perfectly.

  72. Pat

    At first when I saw this, I thought it was a retrograde step to have 2 seperate units.
    One reason I changed from Polar to Garmin, was ther all in one unit to track speed and cadence.
    I used to have terrible trouble keeping the Polar cadence consistant, it was aways moving out of the required small distance, and in the end I stopped using it.

    So I have always found the old GSC-10 unit a little marvel – hardly any issues, until recently.

    About a week ago, my cadence suddenly to count double, so I thought I must be in some Matrix film with me thinking I was only going 100rpm; but in reality I was like a hamster on speed according to the Edge.
    What had happened, was I broke a spoke, and this spoke was the one with the little speed magnet on it.
    The bike shop replaced the spoke, and put the magnet, where they aproximaely thought it went.

    Well it was a few mm to close to the main GSC-10 unit, and the “cadence” brain started to pick that magent up as well as the pedal one.- so doubling the cadence.
    It took me quite a while to suss it out; but all is well again.

    So apart from this all in one units still rock.
    Although I still use an Edge 705 so these new fangled things wont work on that anyway….

  73. David

    Well I have used the new Garmin Speed & Cadence magnet-less sensors for a few days now and I wanted to chime in with my view as a complete un-serious bike rider that tools around on a Trek DS (dual sport) on everything from suburban streets, to groomed railway trails, and even some mild single track. I focus more on running but as a gadget geek I have an Edge 510 on my bike and used the all-in-one Garmin Speed & Cadence sensor with the zip tie attachments and magnets…

    I had the magnet on the spokes, the magnet on crank, and the Garmin sensor itself sitting on a unstable bed of rubber on the chainstay all with little zip ties or screws. It didn’t look bad but WOW… the new system? I love it! I cut off all my old sensors and magnets and I installed the magnet-less sensors in UNDER 2 MINUTES! Rock solid, low profile and essentially invisible compared to my old sensors. They are rock solid too with much more clearance from moving parts. I have no problem with this being 2 parts vs. an all-in one as frankly the sensors are so quick to put on and so invisible on the bike there is no practical downside to two pieces other than I suppose if you are moving them bike to bike all the time. I was ALWAYS fighting a proper alignment of my sensors with the magnet system and often, in particular on trail rides, a sensor might get bumped slightly out of position and lose for example my cadence. It was very always “fiddly” and annoying… this fixed all of it and has been perfect on various rides on all terrain over the past few days.

    Finally I want to address the .5-.9% accuracy difference vs. the old magnet system. First you have to assume the magnet is more accurate, maybe it wasn’t? But let’s assume this new system really is less accurate to the tune of less than 1%… what does that really mean to an “average” bike user? First off remember when it comes to the speed sensor it is being used 99% of the time to show you your speed but NOT being used to figure distance. Your GPS handles that… so the .5-.9% error is what you are seeing on screen at a given time, NOT translating across an entire ride and messing up your distance which is being calculated by GPS anyway! Of course if you are in a tunnel or under heavy tree cover then that part of a ride will revert to using the speed sensor for distance but likely that is such a small part of your overall ride that a .9% error on that little part will add up to an infinitesimal overall error across the ride. The only time the potential error matters at all is indoors on a trainer, but again many of us DON’T use our bikes on trainers and even if we do a .5-.9% error doesn’t mean enough to matter vs. the issues with older magnet based systems. As for “lag” I perhaps see a slight, slight bit in cadence and speed, ie. perhaps the numbers update on my Edge 510 screen .5 seconds slower than with the magnet based system but again from a ride and data standpoint it is meaningless if it takes .5 seconds longer to show I am riding a 90 cadence vs. 85.

    I love the new Garmin system and I think they did a great job. I think for 95% of folks this is the proper choice vs. magnet if buying a new speed and cadence package. If you already have a magnet sensor package and it isn’t giving you much trouble then this too me is a more dubious value BUT it is a fun little purchase for $70-ish that cleans up your bike nicely and feels like the future.

    I haven’t been a fan of many Garmin products lately, but this is a winner.

    • Paul S

      No, when you have a speed sensor, it’s used for both speed and distance. The GPS is a bystander; it shows you where you are, but the Edge does not use GPS for speed or distance (aside from initial calibration if you ask for it) when there’s a speed sensor available. Distance is simply (number of rotations) x (circumference of the wheel). Something that’s accurate to 2 m is better than something that’s accurate to 3-10 and varies, has occasional glitches and sometimes loses satellites altogether.

    • David Corsi

      I was unaware of that Paul, so with the speed sensor GPS is only used for auto wheel size calibration and position track for a map review later? If so like you said the speed sensor is likely more accurate than GPS anyway but perhaps less accurate than the old magnet based speed sensor… That does make an issue if you want as accurate a distance as possible but Again at least for me the difference in accuracy of .4-.9 is well worth it for the clean and rock solid install. Thanks for the feedback.

    • Paul S

      That, and if your device supports it, real time navigation. It needs to know where you are to navigate.

      It’s not at all clear to me that the accelerometer based sensors will be less accurate. As I said earlier, under ideal conditions an accelerometer should be able to tell where in the rotation a wheel is, where a magnetic sensor with only one sensor can only count whole rotations. Under real world conditions, however, it remains to be seen which is more accurate, or whether that matters in the end. There’s a mathematical technique called a Fourier transform that Garmin might be using, which is good at pulling periodic signals out of noisy data. But I have no idea what they actually do. The accuracy might be limited in the end by the ANT+ profile; if the sensor is required to transmit integer RPM’s, then it won’t matter if it could do better than that.

      But I agree with your point about not asking for unnecessary accuracy. For example, from today’s ride, my CatEye said 28.88, the Edge 800 using a GSC-10 said 29.12 (and therefore so do Garmin Connect and Training Center), RubiTrack, which I’ve got set to recalculate the distance from the GPS track, says 29.29, RunKeeper, which also recalculates, says 29.26. I’m not bothered by the differences.

  74. TriAmateur

    Hi Ray (and anyone else who can help),

    Thanks as always for the great info. I picked up a 910xt during the sale last week with a HR monitor, and am now looking to add at least a cadence sensor and possibly a speed sensor as well. I’m pretty amateurish with using metrics more advanced than current speed (I used a reliable FR 205 for about 6 years).

    I’m a little confused. My assumption is that GPS would be better than a speed sensor, so I was surprised to read that the speed sensor is utilized by default other than initial calibration at the start of a ride. Can you comment on why the sensor is used instead of a GPS?

    Additionally, I’m doing purely road biking with this unit, and I don’t plan to be out in the rain with it (though of course you never know). Would you recommend getting just the new cadence sensor, pulling the trigger and getting both the new cadence and speed sensor (or a similar product from another brand), or just saving some cash and getting the reliable-when-not-wet GSC-10?


    • Mark

      Because the speed sensor will be far more accurate than GPS at measuring both speed and distance; provided that the speed sensor is properly calibrated with wheel circumference. And the best way to measure wheel circumference is the roll-out method.

    • Paul S

      Who told you that the GSC-10 wasn’t reliable when wet? I’ve had mine for several years now. I don’t voluntarily ride in the rain, but it happens (last time last Thursday; stupid weather.com) and mine have been wet often. In the winter, meltwater and whatever that junk that PennDOT throws down on the roads have been splashed up on my GSC-10 lots of times. The only trouble I’ve had with my GSC-10’s have been the loss of two cadence magnets (simply dropped off while riding) and one speed magnet misalignment caused by a stick.

      If you’re talking about a normal road bike with standard geometry/tubes, then whether you get a GSC-10 or the new sensors depends on how much $35 means to you, because the GSC-10 can always be found discounted at places like amazon.com. I got both of mine from there for under $30. As David says above, the installation of the new sensors is easy, and there’s nothing to align. But the GSC-10 isn’t that hard to get installed/aligned. No one yet knows if the new sensors will have any long term problems because they haven’t been out very long.

    • TriAmateur

      The lack of water resistance for the GSC-10 seems to be the one negative comment that repeatedly pops up on a number of websites like Amazon.com, so while I have no personal experience with it, and I do take online reviews with a large grain of salt, I have to assume that there’s a decent possibility it’s a real problem.

      I am talking about a completely normal road bike, so I can’t imagine installation of either system would pose any challenges. I’d consider dropping the extra $30 or so on the new pair of sensors, but only if there’s reliable evidence that it’s more accurate.

      Based on the graphs in Ray’s post, it seems to me that the newer, non-magnet sensors result in significantly more noise, which I have to assume leads to less accuracy. Perhaps I’m reading that wrong, though. What are the advantages to spending $70 on the new, non-magnet system over spending half that on the old GSC-10?

    • For the speed sensor portion Garmin believes that the noisiness of the speed sensor I’m seeing is due to placing it on a PowerTap wheel, which they believe is introducing interference. They suggested instead putting it on another wheel. In doing that, I’m seeing much better results – which I’ll summarize in my Edge 1000 In-Depth Review

    • Mr Nofish

      Noise issue notwithstanding, keep in mind you don’t *have* to buy the GSC-10 sensor if you don’t want to. Anything that is ANT+ compatible will work.

      In Europe the Garmin solution is much more expensive (and overpriced IMO, at roughly 60€), so I bought a set from another manufacturer for a little more than half that sum, I have ridden under squalls (although not deliberately) and I’ve never had a trouble.

      For the same reason I never bought the Garmin heartstrap but another one that is way cheaper (it’s the O’Synce but different brand) and I never experienced all the trouble users with the Garmin premium strap seem to complain all the time about.

    • TriAmateur

      I had considered getting something from a different manufacturer, but actually can’t find anything cheaper than the GSC-10, at about $37.

  75. Tom S

    Has anyone had trouble getting the cadence sensor to wake up? I can’t get the green LCD lights to come on.
    Check the battery and it was in good condition.

  76. Ted H

    while I am waiting (saving $$) to buy my Power2max… I tried to pair my Edge 500 to the new speed sensor and the GSC10 (for the cadence only). I can’t seem to make that combination work… I didn’t buy the new cadence sensor because the P2Max will provide cadence info. Any ideas?

    • Scott

      It’s because the GSC10 sends its data as a combo cadence/speed sensor, it doesn’t send the data as two distinct profiles: cadence and speed.

      Like wise, Quarq and Stages meters send their cadence as part of the power profile and you can’t get the cadence out separately. Search above for my name and you’ll see I touch on this when using a Powerbeam Pro.

  77. Roger

    is it comp. with ENDOMONDO (Android) in a ANT+ comp Smartphone?

    Sadly, GSC™ 10 SPEED/CADENCE BIKE SENSOR is the only option in thisisant website 🙁 and I wish to belive that’s an update issue.

  78. Steven Knapp

    Any issues with dropouts on any of the watches with these sensors? I’d think the same issues that plague pedal/crank power meters and the 910XT might be at play here?

  79. Paul S

    Ray, I wanted to ask about the Fenix/Fenix 2. I was unsuccessful in trying to pair my Fenix 1 to the new sensors. Fenix 1 has only a “Bike Spd/Cad” selection in the ANT+ Sensors, and nothing else shows up when you select it, so I suppose that it’s not surprising that it doesn’t work. I think your table (which you repeat in your Edge 1000 full review) should read “No/No/Yes” for the Fenix 1. But the thisisant.com compatibility link that you link to above also doesn’t mention Fenix 2 as compatible. Have you successfully linked your Fenix 2 to the new sensors?

  80. claywalk

    Hi, I recently purchased the speed sensor to go with my 510. I currently have it on the front hub but would like to move it to the rear. will it function with the same accuracy? also – do I need to rollout my wheel rotation distance and enter that info manually? Many thanks.

    • Yes, it’ll work just fine in the rear (assuming no PowerTap hub). No need to roll-out, simply take the wheel circumference on the tire and cross-check the manual for value to enter. Or, use automatic GPS configuration (default).

    • claywalk

      thank you & thanks for all the info on your site.

  81. Mr Nofish

    Well unlike Ray, I only have experience with just one Edge unit, but I would recommend against using the in-built calibration – it would be OK if it wasn’t super-accurate, but what’s worse is its inconsistency.

    Using one of the many tables out there is probably better than leaving it on auto. E.g. 700×23 is 2097 mm. Sheldon Brown has one if you want to check it out, use Group F for Garmin units.

    link to sheldonbrown.com

    Or you can try one of the other methods he suggests.

  82. Markus

    Hi Ray,

    if I want to have a sensor for indoor cycling in a Gym. Is this the way to go? Or is there an alternative available?

    Many thanks

    • For a crank arm, this is definitely a solid way to go. But again, given the Wahoo RPM v2 comes with a new little show pod for the gym (i.e. to wear while spin biking), and given it transmits both ANT+ and Bluetooth Smart, it just seems the way to go.

      I generally favor flexibility, and it has a ton of flexibility.

    • Markus

      Thanks for this information. Then I will most probably wait for the Wahoo RPM. Do you plan to do a short review for the Wahoo RPM v2?

    • Yup, a short review of the RPM v2 is definitely planned. If they release next week I’ll likely aim for the week after.

    • Pierre

      Yes, I tried switching it with the battery of my old sensor (which works for sure) and even a new battery. I was using the GSC 10 before. I haven’t tried to put it on the front wheel. I feel it’s just broken…

    • I’d agree, it sounds like a bum sensor. I’d just ring up Garmin support and they’ll simply ship you a new one (you should be able to do a cross-ship to make life easier).

    • J K Brennan

      My GSC-10 just died last week, tried new battery and got a red light but no green. Tried a couple more new batteries and now I get no lights. My 500 still works as it finds other folks’ sensors when I ride near them (now I just turned it off). Question is, is there any status on the RPM v2? Sounds like they were about to release last month but haven’t seen it yet. Maybe they decided to kill off the v2 before release and are going to create an “RPM v3” that does Bluetooth, Ant+, and has the easy mounting rubber bands with no magnets? I’m thinking I should just get a GSC-10 since it looks like their prices are dropping (as Garmin clears out inventory for their new magnetless version to replace it?) and I’ll get the “RPM v3” when I next upgrade my head unit.

    • They started shipping about 10 days ago.

  83. Scott

    I put the new cadence and speed sensors on my bike which also has a Power2Max power meter. My Edge 800 connected up with both of them with no problem. However when I tried to connect my Edge 500, it would find the cadence sensor but not the speed sensor. After trying multiple restarts and battery changes, I finally tried turning off the power meter on the 500 and the speed sensor came right up. I went back and turned the the power meter back on and now everything seem to be working ok. I suspect the power meter was interfering with the speed sensor somehow but not sure but I hope I don’t have to go through this routine every time I use. Anyone else have a problem like this?

    • Pierre

      I can’t detect the speed sensor either, but I don’t have any power meter. Despite the cadence sensor, I have nothing else on this bike.

      It’s still not working, not matter what I’m trying. What can I try to make it work?

    • On the Edge 500 – I assume you’re on the latest firmware update.

      Further, did you change the search checkbox to be speed-only (or cadence-only)?

    • Pierre

      I forgot to mention I am using the fenix 2. And yes, I’m searching for speed only.

      Just so we’re clear, I can use the these cadence and the speed sensors at the same time, right?

      Thanks for your time.

    • Pierre

      And I should add that the LED is not even green or red when it’s moving or when I’m searching for it with my watch. This is weird. I had no problem with the cadence sensor.

    • Oh, that sounds like the battery is dead. Which, I would agree is annoying for a brand new product. Have you tried swapping it with the other sensor just to see?

  84. I had issues with the magnetless speed sensor giving zeroes now and then resulting in false auto start/stops.
    Moving the speed sensor from the back to the front wheel solved the issue.
    I reported this on the Garmin forum

  85. dries

    hi Ray (or others), do you think these sensors work well with the Bryton Rider 50?
    and how about calibration of the speedsensor: do i manually have to enter a wheelsize, or is there automatic calibration of this sensor or on the bryton rider?

  86. Ira

    In my Garmin 800 how can I configure the old combo Speed/cadence sensor just to do cadence and use GPS for speed. Last week on a century ride I lost the magnet and manually switched to GPS for speed/distance but in doing so shut off the cadence sensor. Thanks.

    • Paul S

      Can’t be done. However, although I’ve never experienced it myself, I’ve seen people write that after a short period of time, the 800 will realize that it’s not getting speed info and switch to using GPS distance/speed. So you might just try leaving the speed magnet off and see what your 800 does. But even better, just go out and buy another magnet and restore the speed sensor.

  87. Allie

    I’m a wheelchair user and (thus) a handbike user. On a handbike the crankset is not located near the wheel so a combo approach to magnetised speed/cadence sensors will not work. As I frequently put my handbike on a roller, I need sensors that are independent of GPS and use a discrete cadence sensor and speed sensor. Bontrager Interchange ANT+ digital sensors might be an option but I have a feeling that the new Garmin magnetless sensors might be just what I’m looking for. Can anyone see any potential problems? I’d be grateful for any comments or suggestions.
    Thanks, Allie.

  88. Geert Vansweevelt

    Do you have any idea on the thickness of the cadence sensor as I’ve got little space between my crankarm and my chainstay. 🙁

  89. I’d just like to add that a couple of comments and pose a questions: this solution will be better for mountain bikes at least, the old solution was a bit vulnerable there. Also with disk wheels on the back you should be able to pit the speed sensor on the front? if you run disk/tri spoke may be more difficult.

    but as a question, does this mean we should be able to use the foot pod as a cadence sensor on the bike?

    There have been a few times when I have been travelling, doing brics, one of my devices has been in for a service (replacing screens / flooded forerunners *groan*) or using someone esle’s bike and just have the edge or just my forerunner and its a bit disappointing that I cannot use the edge for a run and get foot pod data, or use the footpod with the bike on a bric when I take my cheap bike without a fixed sensor that I can tie up in a park and not worrry about…

    • Paul S

      The speed sensor will work on either hub.

      No to the footpod question. The answer is basically here. As I understand it, each ANT+ sensor is using a specific profile, and in order for a receiver to pair and understand what it’s sending, the receiver has to know about that profile. So the footpod is not using the “bike cadence” profile, so an Edge can’t understand what it’s sending. Garmin could conceivably fix that, but the Edge is a cycling GPS, so why would they? Fenix 2, according to Ray’s table above, could use both, even at the same time. But it wouldn’t interpret the footpod data as “bike cadence”.

  90. Steph004


    Is the Wahoo RPM working right now with the Polar V800?
    For foot pod in running?
    For cadence when cycling?


    • Sorta. For cycling it’ll give cadence but the V800 incorrectly thinks it’s a spd/cad combo sensor and overrides GPS with the 0 value from the spd component.

      For running, it’s not a running sensor so it won’t work there.

  91. Travs

    The speed sensor is too wide to mount on a pair of Mavic Crossmax SL that I have on my Lefty equipped Cannondale Taurine. 🙁
    Wish they had made it possible to mount with some sort of adapter.

    • dries

      I have mounted the speed sensor on my Cannondale Lefty (fun works) front wheel.
      was no problem (except a bit thight, but the rubber can flex a lot)

  92. Scott

    Just purchased the Garmin Speed and Sensor package. I just wanted to let others know that I have had only 50% success pairing the sensors with a Timex Cycle Trainer. The speed sensor paired fine, but I cannot get the cadence sensor to pair. I ride a handcycle and was hoping the cadence sensor would be a nice solution.

    • Duckie

      I purchased the Garmin Speed and Sensor package for the Timex Global Trainer. The speed sensor paired but I haven’t been able to get the cadence sensor to pair. Did you manage to get a solution?

  93. Michael

    I recently upgraded from a Garmin Edge 200 to an 800, didn’t care for the new features on the 810 and 1000. I specifically bought the unit standalone so I could buy these new wireless sensors.

    Just picked them up today and followed the instructions though they aren’t helpful at all! It simply does not say how to ‘turn on’ the wireless sensors to pair to my Edge. I know how too activate the wireless settings on the device and search yet it isn’t finding the sensors, so I assume there has to be a way to activate or trigger them for pairing too. Any advice?

    • You don’t need to turn them on, but rather just spin the bike wheel (or crank arm). On the Edge 800 though, make sure you’re searching for a speed sensor or a cadence sensor, but not a Speed/Cadence combo sensor. It’s a different option.

    • Michael

      Thank you for the advice! I just tried the way you advised and was able to pair the cadence sensor but could not figure out how to get the speed sensor connect. If I choose cadence only, it works no problem. Speed only does not pair, nor could I figure out how to use both together since you mentioned to not use the combo option.

      Also to note there are four options that I see on my Edge 800… spd/cad, speed only, cadence only, and speed & cadence.

    • So you’ll want to be in the one for “Speed & Cadence”, which is pairing the two sensors individually.

    • Michael

      Thank you once again! Here’s what I did differently… I played with the solo options again and only cadence seemed to pick up, in about ten seconds after I activated the search. After trying the same with speed only, nothing worked. I then chose the ‘speed & cadence’ option, physically held the Edge near the rear wheel and sensor, and after about 45 seconds the speed sensor finally connected to the Edge.

      I’m hoping that was a one time delayed pair and not every time before I ride that I must wait that long for each to sync up.

  94. Peter

    Hi Ray,
    Is it possible to use the traditional sensor gc 10 on one bike and the new combo on another bike?

    • Paul S

      But… it depends on whether or not the receiver you’re using can handle the separate speed and cadence sensors (see Ray’s table above). If you’re using something like a Fenix 2 or a VIRB Elite, you’ll have to re-pair the sensors each time you switch. For something like an Edge 800? Just remember to switch bike profiles. I have a separate GSC-10 on my road and touring bikes, and the new sensors on my mountain bike, and it all works well with my 800.

  95. Peter

    Your research is great . will wahoo or another company produce a speedsensor too? The garmin speedsensor looks nice, but the wahoo cadence sensor looks much nicer.

  96. Tom

    When will these be available in Europe? Can’t seem to find them anywhere…

  97. Sam Lewis

    So with the speed sensor
    It will calculate speed n distance indoors?
    But when outdoors the sensor will override the gps for speed and distance too
    Am thinking of getting a stages power metre that will do cadence too if I’m right so want a speed distance sensor for indoors on the turbo
    Cheers sam

  98. Sam Lewis

    And distance indoors too is that right
    But when outdoors does it override the gps speed/distance

  99. Michael

    Hey Ray, thank you for helping me get the sensors set up last week. The instructions weren’t helpful at all. I debated on getting the cadence only sensor though my LBS talked me into getting the combo unit because “why not?”. I don’t use a trainer so I just took it as a more accurate way to track my speed.

    Except my findings so far is that it isn’t. At all. The first time I used it, my speed seemed to be much lower than usual, on average. The second time I used it, numerous times through my ride my Edge would auto pause while traveling at over 20mph because the speed sensor was showing 0mph on screen! Over one stretch of bridge it was a symphony of beeps from the auto-pause, auto-start sounds.

    I just raced over the weekend and specifically shut off the speed sensor using cadence only because I didn’t want to risk having any of my data skewed. Could you provide any insight?

    • I assume you calibrated it? If so – what’s the calibration value? (It should be roughly in the 2096 range, +/- perhaps 30).

      Failing that, it may be a case of a bad sensor – or potentially a bad connection, but that seems unlikely.

    • Mr Nofish

      You might be interested in my comment #216.

    • Indeed, that lookup table is pretty solid. Here’s the link to NoFish’s comment #216 (since comment numbers are dynamic): link to dcrainmaker.com

    • Mr Nofish

      Thanks Ray, I was looking for a comment link but couldn’t find one.

    • No worries. To link to a comment simply hover over the date/timestamp, which links directly to an individual comment (and keeps the link permanently).

    • Michael

      Not sure how you mean by calibrating it… it did it automatically within a few minutes of my first ride.

      I have the sensor strapped on the hub of my rear wheel, specifically Reynolds Strike 66mm on a 700×23 tire. Under “wheel size” on my Edge settings it shows “automatic 2093mm”.

      What concerns me not only is the speed seeming to be very low, but the auto-pausing showing 0mph randomly on a ride, primarily when I’m going faster than slower.

    • Calibrating in this scenario I was referring to specifying a wheelsize. The 2093 sounds quite normal though and inline. Given what you’re seeing, I’m going to guess the sensor is defective. Even a signal dropout wouldn’t typically result in that. You could try (outdoors) putting it on the front wheel and see if the issues disappears (as that would indicate signal dropout).

  100. fuel98rider

    I received the new cadence and speed sensor to put on my full suspension mountain bike. I’ve had the older GSC-10 on it for many years, and just dealt with the fact that the magnet would eventually get knocked out of alignment, or the sensor would get whacked, and I would have to stop and fix. Sometimes I would notice it quickly, other times it might not be until the end of the ride. Either way, your speed and distance data gets hosed. These new sensors eliminate that need.

    Spent this past weekend in NC, pre-riding for ORAMM with the new sensors. These new sensors do an admiral job of keeping the speed and distance updating through the dozens of switchbacks, and are definitely accurate. Two weeks prior, I rode the same course, with the same bike, except for the GSC-10 on the bike. Distance was 49.61 for the new sensor, and 50.1 for the GSC-10. For me, that’s well within the range I would expect, and have no issues with its accuracy. Cadence measures well, and matched my cadence on the 9 mile climb from before. With all of the mud, water, and overgrown trails I rode on, not having to worry about the sensors being knocked out of alignment at all is a welcome relief mentally.

    The one thing I would suggest for anyone using these is to scrap the idea of using the gps to figure wheel size. Use the ERTO number on the tire, plug it into one of the many online calculators, and then set it manually on the gps. I use this one which yields good results: link to berkshiresports.org
    Many of the charts listed when doing a google search will get you in the ballpark, but not the exact number. For tires that have no correct size listed (say a 29×2.2), or are undersized (any Conti mtb tire), using the ERTO number is much more precise and will yield higher accuracy for distance.
    I’m happy with them, and will be ordering another pair for my hardtail mtb.

  101. Tim

    Hi DCRainmaker

    I have recently purchased the new Garmin cadence sensor for my Garmin 800 (which is also new to me). They do not seem to be talking to each other, so I am in need of help.

    I suspect the battery may be flat…..is there a way to tell this? If I take the battery out and put back in again a green light flashes and a red light flashes and then nothing.

    How do I know if the GE800 has recognised the cadence sensor?

    Sorry about the basic questions, still trying to get my head around the GE800!

    • If you look in the sensors menu, it will show connected or not. If it goes connected but then drops out after a minute or two, then that’s probably the case. Else, in the Edge 800 you may be trying to pair it as a speed/cadence combo sensor as opposed to just a cadence sensor.

    • Paul S

      Yeah, but if I remember when I paired my 800, you have to do it that way. It’s another case of hidden UI. First you select speed/cadence from the right bike profile, and start trying to pair. It fails, of course, but if you then go back and choose speed/cadence, a new menu item will appear, something like “Sensor Details”. Choose that, and you get a choice which includes “Speed and Cadence”, which is the one you want if you have both sensors. I think there’s an individual “Cadence” selection if that’s all you have, too. Now with everything paired, when I choose Speed/Cadence -> Sensor Details, on my mountain bike it shows the separate speed and cadence sensors, while on my road and touring bikes it shows their individual GSC-10’s.

      My cadence sensor works fine, but it usually takes about 40 spins of the crank before it pairs with my 800 initially. After it pairs, it stays connected even through long descents with zero cadence or stops. I’ve never been able to find the light on my cadence sensor, but on both speed and cadence sensor they’re suppose to flash the first few rotations before going dark.

    • Tim

      Done!…….Thanks very much for your help.

  102. Steph004

    Hi Ray and others!

    Is this combo working with the Viiiiva HRM transmitter?
    Will I be able to have data on my iPhone with the 4iiii ? It was working with the old Ant+ speed and cadence but i will prefers to have it magnet-less and with this kind of “quick and easy” attach.


  103. Alex

    Hey there.
    I just picked up the cadence sensor to go along with my XT310

    I can’t for the life of my get these things to pair.
    I have the latest version of software on the XT310.
    I go to Settings -> Bike Settings -> Bike 1 -> ANT+ Spd/Cad -> (check bike sensor is present) -> More -> (check cad Sensor). Wont pair.
    Try to go back on menu and ‘restart scan’, it just goes out one menu again.

    Any ideas anyone?

  104. Jason B

    I am thinking about buying these speed and cadence sensor to be paired with my iBike Newton power meter. It seems like this would work since they are ANT+, but my concern is if any calibration needs to be done with the speed sensor. Can anyone confirm if I will get correct readings pairing these sensors up with a non Garmin unit? Thanks.

    • It works with non-Garmin devices just fine. Past iBike units have supported speed-only and cadence-only sensors, but I’m unclear if the Newton supports it.

    • Jason B

      Thank you for the quick response. I figured that it would work, and you are correct in that the Newton supports separate sensors. Thanks again.

  105. Any hints on when Wahoo is going to make the BTLE/ANT speed sensor available?

    • They haven’t committed to a speed-only sensor, they’re still deciding if there’s a market. As for the cadence-only sensor, that’s out now. And for a combo sensor (speed/cadence), they’re saying later this year.

  106. Navnit Ranjan

    HI Rey,

    I have fr620 and thinking to go for ANT+ SPEED & CADENCE COMBO.
    Are they compatible Rey?


  107. Jonas Decraene

    Hello Ray,

    Have you been able to confirm these new Garmin magnetless speed and cadence sensors do work with the Mio Cyclo 505?

    I have bought these for my Cyclo 505, but despite a couple of tries I have not been able to get the Mio to detect these sensors. I also tried removing and putting back the battery of the speed sensor without any result.

    Now I don’t know if
    a) I’m doing something wrong
    b) my brand new sensors are DOA
    c) the bug-ridden Mio v4.0 firmware is causing the problems detecting the sensors

    The messages from Mio are also ambiguous and confusing. On the MioShare homepage the details for the upcoming v4.1 firmware update mention a better detection for ‘some sensors’, while a Mio representative replied to me on the Facebook page they won’t be adding any ‘functionality’ and the update shouldn’t make any difference towards my problem.

    Do you know something more about this?

    Thanks in advance!


    • My 4.1 unit arrives within the next 24 hours (they swapped out mine so I don’t have one in front of me at the moment). My guess is that it’s not correctly handling the longer sensor ID’s that the new Garmin sensors use (6-digit vs 5-digit).

    • Jonas Decraene

      Thanks for the quick reply!

      Very curious about your findings!

    • Jonas Decraene

      Hi Ray,

      I hope I don’t sound impatient, but did you have any luck connecting the Garmin magnetless sensors to the Mio Cyclo 505 after the v4.1 update? Or am I asking too soon? It’s mainly because I would like to know if I should use the small time frame I have left for returning them…


    • It doesn’t appear to work/pair for me. That said, things could change of course before final release. I’ve sent over a note to them asking about it.

    • Jonas Decraene

      Ok, thanks for checking! Think I’ll hold on to them for now, although it doesn’t seem very promising. Hope it’ll work, or either Wahoo decides to develop a magnetless speed sensor (as their TICKR works perfectly with the Mio) …

    • Tim K

      It doesn’t work on my 4.1 Cyclo either and the Ant+ website shows its only compatible with the basic Cyclo in the smaller case, not the 305/505 series.

      I’m going to try and run them through my Viiiiva HRM which can bridge to Bluetooth Smart in the hope that it then appears as a combo device.

      It’s a real shame if Mio doesn’t include these profiles as I cant fit the combo sensors on my carbon fibre mountain bike. After all their issues and other bugs I’ve found with the format of the gpx data, wheel size etc I’m very tempted to switch to Garmin

    • Tim K

      So it partially worked. Both sensors picked up through the Viiiiva but huge dropouts in the data

    • Which, mostly makes sense because the Viiiiva round-robins the data to devices that don’t fully support the Viiiiva API (most devices).

    • DafLJ

      I’m interested in any outcome to this as well. I’ve got a Mio Cyclo 505 but I’m really not keen on the speed/cadence sensor that comes with it, although I’m happy with the unit and prefer it to my old Garmin.

      These sensors are much cleaner than the Mio supplied ones, and I’d really like to run them together – but until there’s some confirmation that they work I’ll hold off on purchasing them.

  108. ML

    Just got the cadence sensor to try with a Timex Cycle Trainer. Wish I had seen Scott’s post before I ordered it. I can’t get the Cycle Trainer to recognize the cadence sensor, so I guess it’s just not compatible and I doubt Timex will upgrade the firmware. DC Rainmaker – I know you have both products, have you tried to pair them together?

    • Interesting, I wonder if that’s having an issue with the longer sensor ID’s that some sensors can be used. I’ll try and dig it up.

    • ML

      Thanks, curious to see what you find (i.e. if you can get it to work). I really want a magnet-free setup and was hoping to use GPS for speed and a cadence sensor like the new garmin. I guess the other option would be to wait until the Wahoo RPM is easier to get.

  109. Jesse

    Hey there, I’m still new to road cycling and keep coming across your site. Awesome posts, keep it up!
    I have a question….

    I have a Trek Madone 3.1 that has the SpeedTrap mount built into the fork. I’d like to use the Bontrager SpeedTrap for speed and this new Garmin sensor for Cadence only. I’ll be connecting to a Garmin Edge 500. Will I have any issues, or is an ANT+ sensor an ANT+ sensor?

    • Mr Nofish

      Jesse, definitely the latter. In general, everything that is ANT+ certified should work with anything that is ANT+, but there are certain exceptions.

      The Edge 500 should have no trouble handling your choice of sensors anyway.

    • Jesse

      Awesome, thanks! I got the cadence sensor just need to order the SpeedTrap now 🙂

  110. Daniel Gray

    My sensors arrived this morning. Had a quick ride before heading out for the day and had no problems with calibration or set up. First impressions are very good and I’m glad that I found all the information I needed here before tracking them down. I got a very good deal on both from a guy on eBay and couldn’t be happier!

    Thanks DCRainmaker for your ever informative website.

  111. Doug H.

    I have a Garmin 800 with the latest software loaded. I am using the new magnet-less cadence and speed sensor with “speed and cadence” selected on the 800. It finds the sensors because they will blink and then go steady on the main page and drop the sensor ID number on the appropriate page. The issue is there is no data being provided for speed or cadence or even from my Heart Rate Monitor (HRM) in the display fields. Any suggestions on how to rectify this problem and please keep up the superb job of making us all informed consumers/athletes!!!

  112. Jip

    Thanks for this detailed write-up for this new sensorkit. I installed and used mine yesterday for the first time. Despite it working almost perfect I noticed something odd. On my 150km ride a hade 2-3 times the unit auto-paused and continued recording. So the unit stopped and within a split seconed continued again.
    To be honest there is hardly any time/distance lost but I can’t figure out how this happend. It happend on very differend spots on the course, all without obvious sources that count interupt the connection.

    Have any experiences with this aswell?

    • I don’t believe the Garmin Edge units actually use the speed sensor for Auto Pause, but rather only GPS. Thus, if you got into a brief moment where the GPS thought you paused (totally normal on a 150KM ride), I could see how that happens.

    • Mr Nofish

      As usual I can only speak for my lowly 500, but the Edge will auto-pause whenever the speed falls below a certain threshold (that can be set manually or left on auto).

      If the speed sensor stops transmitting (because it runs out of juice, or maybe you knocked it off), it will autopause until you either restore the sensor functionality, OR disable the speed sensor from the menu.

      That said I have seen occasionally the same problem with a conventional speed/cad combo, and I’ve never figured out the cause. It might be disruption of ANT+ communication, but in that case it should be affecting other sensors as well.

    • Jip

      Thanks for your reply. Today during my 25km commute ride to my work it happend twice again. Funny thing on all of my previous rides (10000+km) it only happend when I drove through some long tunnels. So despite it might be caused by the GPS, it doesn’t happen if I don’t use the sensors? Any suggestions?

    • Hmm, I don’t really have any great suggestions there to be honest. I don’t tend to use Auto Pause, so I don’t have a ton of experience in troubleshooting it that much. Sorry!

      You may want to check out the Garmin Forums, as sometimes the Garmin cycling folks stop by there and may have some ideas.

    • Mr Nofish

      Jip, with GPS alone you might experience a different set of problems (e.g. in tunnels or if there’s more or less dense foliage, plus I keep finding small jumps in my recordings when examined in a program like Golden Cheetah).

      Some random ideas:
      try moving the sensor to the other wheel.
      Reset the head unit and pair the sensor again.
      Reset the sensor by installing the cell with reverse polarity for a few seconds.

    • Mr Nofish

      Concerning my previous comment about ANT+ disruption and heart rate, today I went out for a ride without my ANT+ transmitter. Brought along my old Polar RS200sd instead which uses a digital, coded transmitter (the T31) which my Garmin quite obviously does not pick up.

      Around 30 km in, my Edge 500 suddenly finds the heart rate sensor and displays a rate, losing the signal shortly afterwards. I thought maybe my transmitter ended up in my back pockets somehow and woke up because of sweat wetting it. But no: later I found the transmitter back at home – so whatever the Edge picked up couldn’t have possibly been it.

      TL;DR it’s possible we simply don’t notice interference at the heart rate level as often as it happens with speed or cadence – due to differences in how the head unit handles different sensors and the effects of said interference.

    • Paul S

      Did you get close to someone else wearing a HRM? A few weeks ago, my 800 paired with a passing power meter for about a minute, even though I have power firmly set to off on all of my profiles. Kind of annoying.

    • Mr Nofish

      Nobody was close, I was in a rural area, the only building an out of town graveyard – I’ve spotted runners before in that area, and there might have been a mountain biker where I couldn’t see it.

      That should rule out another ANT+ signal but, even though ANT+ is not supposed to have a lot of range, the Edge once picked up my speed sensor on a different floor, and today was a windy day too.

      The units shouldn’t be actively looking for new sensors unless you tell them, imagine that happen in a race…

  113. T Elliott

    Regretfully, in the two months I have had the new cadence and speed sensors I have had nothing, but trouble keeping the two devices connected to my 810. I have found no reliability as far as hoping to keep consistent data from my rides. I am in the process of trying to exchange both units and more likely will go with a refund. I have had the units quit working before rides, during rides and once they loose connection my 810 will not pair with either no matter what I try and I have tried everything. Thankfully with GPS speed sensors are not needed unless you are on a trainer so I am more than happy to use my GCS10 units for indoor use. The cadence sensor works for a few rides then quits then repeats the process. I have changed the battery twice in two months since it seems to be the only thing that temporarily remedies the pairing issues. The inconveinence of messing with a device during a workout is maddening and I have actually had to take the cadence sensor off the crank arm and remove the battery to try and get it working. This pretty much kills a good workout. I love the idea of the cadence sensor not needing a GCS10 unit to get data and the clean look, but I am really hoping there will be other alternatives in the near future from another manufacturer. As a side note I have had the same problems with Garmins HRM, but not nearly as much. There is always the possiblitiy of my 810 unit being the problem, but when I don’t seem to get any consistency with any of Garmins products it is really hard to figure out the root of the problem.

  114. Jerrod

    Ray – have you heard whether these magnetless sensors might be incorporated into the Performance Bundle set?

    As a soon-to-be first-time Garmin owner, my options are to buy the Edge 510 $399 bundle with the old speed/cadence sensors, or to spend a whopping $509 for the device-only 510, adding the HRM, out-front mount, and new sensors a la carte.

    This seems a bit silly.

    • Hmm, good question. I’ll ask.

    • Jerrod


      I’ve sent an email to their customer support. I don’t expect to hear much, really, but if I do, I’ll report back.

    • Jerrod

      I’m sure you have better contacts than the standard e-mail support group, but just for reference, here’s what they’ve said:

      “At this time we do not have anything slated to change in the bundle packs for the Edge 510. I do apologize for any inconvenience that this may cause. There could be something that is possible released in the future just not at this time. We here in the support center do read your submission and they are archived for review but do strongly recommend that if you have an idea or suggestion for improvement that you submit it directly to our engineers and design team. You can do this by visiting link to garmin.com and submitting your idea.”

      Basically exactly what I’d expected, but hey – I’ve registered my suggestion.

      I’m really in no hurry to switch from my current setup (logging to phone w/ Strava + BlueSC + Polar H7, no HUD) to a Garmin bundle, but whenever this 510 bundle is modernized — or the 510 itself eventually replaced — I’ll make the jump.

    • Mr Nofish

      I don’t think they ever upgraded any bundle in the past, so I wouldn’t hold my breath – even new models have been released with older accessories when the new ones were already available, e.g. the FR15 comes with the old, old style HR band.

      Anyway, where did you get your pricing info from? A quick amazon.com search brought up the bare unit at $330 and the bundle at $400. The latter obviously offers more bang for the buck, but it makes sense to me that the bare unit would cost less, not more.

    • Jerrod

      Thanks for the reply. Yes, I suspect it’s silly to wait.

      As for the pricing, the $500+ number I threw out there assumes a first-time buyer wants to build a magnet-less bundle a la carte, to be feature-complete versus the $400 Performance Bundle:

      $329 Garmin 510 only
      + $69 magnet-less speed and cadence
      + $39 out-front mount
      + $69 HRM

      Sure, I could get a cheaper mount, and sell off my existing BT HRM and BlueSC to offset the a la carte build.

      But, I suppose I’m trying to find an excuse to convince myself to wait a while longer on a Garmin upgrade. I really need to just get out and ride more often / harder / faster / longer before it’s truly justified. All of this is just my rabid geekery getting ahead of my actual athleticism.


  115. philip j

    Only just discovered this. Great review, thanks

  116. Mike

    I have experienced a lot of “noise” or fluctuation with the speed sensor when riding outside. Guess it is coming from power lines and the such. Never had issues with my cateye setup. Would think garmin would have a way to reduce this occurence. Ideas or personal experience with this Rey?

    • Any chance it’s on a PowerTap wheel? Also, any change it’s a touch bit loose?

      In doing a LOT of riding with them, I’m not seeing anything really visible as long as it’s not on a PowerTap wheel.

    • Mike

      It is not on a powertap but it is being used with vector. Don’t experience any issues indoors and only in certain areas where I ride. In fact, it is in the exact same areas that I experience the interference every time. On a large loop ride it is always by a certain row of light posts. And this last weekend at the same portion of the out and back portion of a tri. Sensor fits tight and flush to the hub.

    • Yeah, definitely no issues with Vector cross-interference (at least for me on multiple bikes).

      That is very odd on those light posts. I wonder if there’s something run under the ground there power-wise. Strange.

    • Nick Ioannou

      I have experienced speed fluctuations when suspended on a bridge – eg Anzac and Iron Cove bridge. However it works well on Pyrmont bridge. The fluctuations I see are by about 10kph where it would read 25, then 35, back to 27 upto 37 etc….

      I wonder how this magentless speed sensor works – does it require the earth’s magnetic field which is too far when up on a bridge or is it interference from the bridge/metal structures?

    • Robin


      The magnetless speed sensor works off of an accelerometer, not magnetic fields. It’s possible that the accelerometer detected motion in those bridges.

  117. Arnaldo Ferreira

    Hi, I`ve just bought the magnetless sensor to use with my garmin edge 500 and with my suntoo ambit2, I`ve no problems with pairing it with the ambit2 but I can not pair with the edge. I`ve already changed the sensor from ANT+ Speed/Cadence to ANT+ Speed ANT+ Cadence, but it can`t pair, do you have any sugestion?

  118. Mischa Pasternak


    I have been out of the loop with cycling for many years, so when gearing up again (pun intended), a lot of time has been spent here on your site as part of my research. The time spent was lengthy, but very well worth it.

    I have an ’04 Trek 2300 that I picked up on eBay while overseas in 2006-2007 for a song. Just over $900 with shipping. It’s a big frame, I am 6’6″ and the seller had upgraded to a Madone, hence the great deal! But due to injuries, had not put more than a hundred miles on it until this season.

    So I am now the proud owner of a Garmin Edge 810 with these magnet-less sensors, and a PowerTap. Absolutely amazing all around so far! I am not a huge data junkie, but for me, ease of use, accuracy and reliability are a must.

    Thank you for the detailed reviews and ongoing discussions afterward. Not only did I end up buying more items, but truthfully did it all very healthy margin below my expected budget with far more features. Makes those purely brainless, fun or totally unplanned excursions into useful gauges! Never thought I’d feel like I had the quality and information that high end pros do.

    Keep up the great work!

  119. Jon Moro

    Do the new cadence and speed sensors work on a Cateye Stealth 50? This is Ant+ says they should but I’ve been having trouble getting the computer to actually display speed and cadence from the sensors…They both pair up to my Stealth 50 just fine, however I can’t seem to get the sensors to actually pick up my speed or cadence from the sensors.

    • Matt Hunt

      Did you have any luck getting these to display speed and cadence on your Cateye Stealth 50? I’m having the same problem. Pairing worked, but the data isn’t displaying

    • Any chance you have to specify a wheelsize first?

    • Matt Hunt

      Unfortunately, wheel size was set already, so that’s not it, but thanks for the suggestion!

      I think I’m going to give up on it and return the Garmin sensors. Will probably get the Wahoo dual ANT+/BLE instead.

  120. Deon


    I bought myself a new Suunto Ambit 2 S and a set of these.

    I cannot get them to pair. Probably because I am doing something stupid.

    I installed both and attempted to pair as a bike POD. On first attempt it failed, thereafter success. Turns out I can only read the speed.

    I have tried everything I can think of, including removing the speed sensor. With only the cadence sensor nothing pairs. The cadence sensor does flash when I reinsert the battery and when I rotate it after its switch off period.

    Sorry to bug you for support, but you seem to be the most knowledgeable guy on this matter in the world!

    Thanks in advance!

    • Renato


      were you able to get these paired eventually? I just bought the ambit 2s and am shopping for cadence/speed sensors and this one came up as being compatible

    • AListair

      Renato (and Deon?),

      I’m awaiting arrival of my Suunto 2 s and wondering what you have found with regard to cadence/speed sensors. I’m leaning toward going with the tried and tested Garmin GSC 10 (albeit with a modification I’ve seen people discuss: a small, super powerful magnet on the crank instead of the zip tied unit).



  121. Ray Taylor

    Hate to rain in the love fest .. This is the worst possible upgrade. The cadence sensors works well. The speed sensor mounted correctly on the rear wheel hub is anything but impressive unless anyone believes that the PB downhill speed went from 71.1km/hr to 91.8 km/hr! I wouldn’t want to be on my bike at that speed. Wildly fluctuating values once it passes 50km/hr very very crappy product.

    Being returned tomorrow … GSC-10 to be re-installed pronto (to be paired with the new Edge 510

    • Did you double check wheel circumference value? Otherwise, given your the first person I’ve heard from otherwise with an issue – I’d ring up Garmin support to troubleshoot.

    • DC

      I’ve had the new speed sensor on for a couple of weeks and paired with the Garmin 510 it has worked great… Until this morning after I updated the 510 software from 3.10 to 3.20. Now the speed readout jumps all over the place. 32km/h and second later it’s 18km/h and back up to 28km/h in a matter of seconds. It worked fine before the update. Contacting Garmin now!

  122. John B

    I thought I saw one of these speed sensors lying on the road with a snapped band during the Gran Fondo Banff.

  123. Craig D

    Will the new cadence or speed sensor work with Garmints ANT+ Adapter or Wahoo’s adapter, as I’d like to use one of these on my ipad, but want to make sure that they will place nicely together first.

    • mike

      Yes it will work with the wahoo sensor. I use the wahoo phone case with built in adapter for my bike computer. It is paired with vector pedals for power and cadence and the stand alone speed sensor. One of the advantages of the sensor is you can move it to the back wheel for the trainer and the front wheel if you have a disk. However you need to make sure your hub is wide enough to fit it on the hub in a horizontal position. This is not a problem in the front but could be in the back. Just depends on your wheel.

    • Craig D

      Appreciate the reply.
      I’d prefer to use the Garmin option as I have a gift certificate that can be used for it, and I imagine it should work if the Wahoo does. I’d like to use it to plug in to my ipad and then use traineroad or cycleops virtual trainer for indoor workouts over the fall and winter.

    • Mike

      I believe ray mentioned somewhere that the garmin ant+ key only worked with garmin connect? Search around if this is true and you want to use a different software.

    • Craig D

      Very useful information to know, and also correct, as stated here:

      link to dcrainmaker.com

      Looks like Wahoo it is, which I am thankful to know in advance of making a wasted purchase!

    • Correct, don’t buy the Garmin key. Buy the Wahoo one. The Wahoo app is fully compatible with these sensors. Apps beyond that will vary by app (many are).

  124. Ricky Aquino

    Have you heard about any clearance issues with the cadence sensor? I have a felt B16 w/ a Sram Red crankset and I have clearance issues using the GSC-10 along with the ziptie magnet provided. I’m hoping this will solve my clearance problem!

  125. Jacov

    Might be worth noting, that if you would like to pair the speed sensor only (Looks alot cleaner and ‘pro’ than the old ones), that you would have to switch the ‘About’ section to ‘Speed only’ when choosing to pair.

    I had the hardest time trying to figure out why it wouldn’t pair (I use the vectors which calculate cadence, ergo, only the speed sensor)
    Great review as always Ray!

  126. joerg

    I bought the new garmin speed and cadense sensors to use with my Garmin edge 510 I am able to pair them and my devise finds them one by one but I am only able to use one at the time , meaning I only can use speed or cadense I am not able to use them together , does anyone knows what could be the problem

    Thank you very much for getting back to me


  127. Danky

    Hey, I’m having the same issue as Joerg above! Just picked up my speed / cadence set and they look cool and are very easy to pair… individually on my Edge 800. Is there some magic trick need to pair both at the same time? A reasonably long search online finds no information on this at all 🙁

    Cheers in advance


    • Paul S

      They certainly pair with an Edge 800, since mine work with my 800. What are you telling it to pair with? You should be choosing “Speed and Cadence”, not “Speed/Cadence”. You may have to go back and look again at the menu entries, since Garmin is fond of hidden UI and changes the UI behind your back. As I recall, I had to choose “Speed/Cadence”, let it fail, and then going back suddenly “Speed and Cadence” was an option.

    • Danky


      Thanks so much Paul S… that’s just gone and worked immediately! It’s sooooo easy when you know how 🙂

      Many thanks indeed


  128. Frank Tucker

    I tried to make these stand appart garmin speed and cadence sensors work with the cateye stealth 50 and they don’t want to work. Anyone able to get these to work together?

  129. Tarak Abu Adam


    Will this combo set work with the Bontrager Node 2.1? And which HR monitor would you recommend if I were to get this combo to go along with Node 2.1?

    BTW great website! And thanks for the insight. Keep up the awesome work.

  130. vonnman

    Hi Ray,

    Couldn’t get any other info on these except on your site, hope you can help. I got both speed & cadence sensors, installed them on my bike & paired them with my Fenix2. I got the cadence sensor to send me data already but it seems the speed sensor (even if it’s connected & paired to my Fenix2) is not sending any data at all. I used them on my bike trainer and my mileage was zero after a session.

    I also noticed that the cadence sensor will stop working if you stop giving you data if you stop pedalling and resume. When I resumed, i had to give it a little tap to let it start sending data again hehe!


    • Did you calibrate the speed sensor with a wheel size? Also, did you change on the Fenix2 the mode to indoor so it uses the sensor?

    • vonnman

      oh… didn’t do both. Thanks Ray!!!

      I just paired the sensor and chose Bike mode (not indoor). Didn’t mind the indoor mode since this was not present with the 910xt.

      Appreciate your advise! 🙂

  131. hopester

    I recently bought the cadence sensor and had trouble getting it to switch on. Here is a little tip to get it to sync straight away.

    Less is more 😉 If you rotate the crank slowly (say 25rpm), the sensor switches on every time within 2-3 revs. If you jump on your bike and take off at high rpm or spin the cranks backward at speed before getting on, it can take ages to wake up.

    • vonnman

      thanks for this tip @hopester, I think this is what happened to me. Got on the trainer, spun for a bout 20mins, got off – did some squats for about 4mins, when I got back on, sensor probably was sleeping and spun right away, should have ‘awakened’ it first.

      appreciate this! thanks!

  132. George

    I currently have an Edge 510 with the bike profiles setup for each bike. Each bike has a GSC10 connected, and the profiles are mated to the different GSC10’s.

    I’m considering replacing these two GSC10’s with 1 combo of the magnetless sensors. The theory being I can easily move the cadence sensor between the bikes.

    My question is can the Edge 510 have the two bike profiles connecting to the same cadence sensor and/or speed sensor?

  133. Andrei

    It would be very nice if they implemented the separate cadence/speed ANT+ profiles in other Garmin devices like the GPSMAP 64 series. I never even thought of checking for compatibility and I was in for a not so pleasant surprise.
    I tried to ask for this feature through the support. After several e-mail exchanges (waiting ~5 days for every response) they finally concluded that the devices are not compatible -> basically what I told them in the first message, when I asked if they plan to include this in a firmware update. Then, they directed me to ask for this feature through some customers’ ideas program so I did – they thanked me for my brilliant idea 😀 and that’s the last I will probably hear of it.

  134. Brad Doucet

    Did you ever have trouble using the speed/cadence sensor and a Garmin 620 on a trainer indoors?
    I tried turning the GPS off,however I still can’t get speed and miles to show on my watch.

  135. Johan

    Is the new Garmin speed sensor compatible with Trainerroad? In that case, how is it calibrated?

  136. Jorge

    So I just bought this sensor only to have the latest and greatest however, I didn’t upgrade my edge 810 to the edge 1000 because I am not a fan of it’s size. Anyhow, I have a question regarding the speed sensor. Does it have to go on the front or rear hub? I ask because I have Chris King hubs and the rear hub is more cone shaped than cylindrical and personally I’m not sure how I feel about mounting a weight to my hubs front or rear for that matter…..all input is welcome. Thanks!

    • Paul S

      It doesn’t matter. Either hub will work.

    • Jorge

      But does it have to be mounted on a hub?

    • Jorge

      But does it have to be mounted on a hub? And does adding this sensor to your hub throw off your wheel’s performance or balance. Does the average cyclist go fast enough where centrifugal force could be a factor in the dynamics of the wheel itself?

    • Paul S

      We can figure that out. The centrifugal acceleration is \Omega^2 r, where \Omega is the angular speed. The fastest I typically go on my mountain bike (downhill, of course) is about 35 mph, so let’s say 60 km/hr, or 16 m /s . The wheel has a circumference of 2 meters, so 8 rev/s. So \Omega (2 pi * revolutions per second) is about 50 radians / s. I’m not going to go out in the garage at this time of night and measure the hub, but I think it’s about 2 cm or 0.02 m in radius at most. So roughly the centrifugal acceleration is 50 m / s^2, which is about 5 of the acceleration of gravity, 9.8 m / s^2. So at the highest speed I go, the centrifugal force is larger than the gravitation force. But the sensor itself weighs only 14.2 gms, so the force it exerts is 0.2 newtons, or .44 pounds, which is easily dwarfed by the weight of the wheel itself, let alone 250 pounds of me, bike, and other stuff I carry. (The centrifugal force exerted by the rim and tire will be much bigger, because they’re farther out.) So, no, the sensor isn’t going to unbalance the wheel, and in fact, I don’t feel anything at those speeds (but the necessity of watching what’s in front of me on the road in case it becomes too sketchy). If you use a wheel magnet it might exert more force, since it’s much farther out even though it’s lighter.

      Of course, it’s late Eastern Daylight Time and I may have screwed something up. But the fact remains, I use the sensor on my mountain bike and don’t feel the sensor at all, so it’s really not worth worrying about. I don’t suppose it has to be mounted on a hub for it to work (all it does is sense the rotation around its axis parallel to the axle), but it’s designed to be mounted that way.

    • Jorge

      Thank you Paul for your in depth explanation. Believe it or not I called and emailed garmin about this and the best response I got was “potato”.

  137. Mr Nofish

    I guess the sensor could be attached to any non-revolving part of the bike as long as a reading of 0 is deemed satisfactory.

  138. “While we’re at it, Wahoo does still have plans for an updated Blue SC Speed/Cadence combo sensor later in the year (dual-ANT+/BLE), and are determining whether there will be enough demand for a speed-only model as well. ”

    Any more info on this?

    I’d REALLY like to get something like this as the 4iiii Viiiva is completely useless as a ANT+ / BTLE bridge.

  139. Josh Potter

    Hi Ray,

    Just wanted to ask, I don’t currently own a speed/cadence sensor, but I’m looking to get them for mainly my turbo, which sensor would you recommend? Presuming cost isn’t an issue.



    • If you don’t mind a magnet and combo sensor, I’d wait a week or two and pickup Wahoo’s new Blue SC dual ANT+/BLE sensor (Speed/Cadence combo, just like their existing Blue SC).

  140. Jorge Gonzalez

    Your site is excellent !!! I have a question, I have the fenix 2 with the HRM-RUN band, can I sync the band and these sensors at the same time?

  141. Tom Hunt

    I have just got these sensors today and paired them to my 910xt.
    If I spin the wheel i get speed readout as expected.
    If I spin the pedals I get cadence AND speed readouts even though the wheel is stationary.
    Is this expected?

    • Tom Hunt

      A small update on this. pedalling backwards so that I don’t spin the wheel makes both speed and cadence turn up on my 910xt which is odd. But pedalling forwards the speed sensor takes over and to be honest having just taken it out for a 40k spin everything seem to be working great with these sensors.

  142. Joe Peiso

    Has anyone had any experience pairing more than one Ant+ cadence sensor with the Fenix 2? I have a Ant+ sensor on my spinner that paired instantly, but I have had zero luck pairing either the Ant+ speed or cadence sensors on my road bike?

    • You can only pair one bike’s worth of sensors, the Fenix2 doesn’t support multiple bike profiles. So one cadence (or speed/cadence combo), or one cadence + one speed, or one combo.

  143. Marcelo

    HI there

    I have just bought the new garmin vivosmart with heart rate stripe and the speed and cadence pack – My question is how do I track my heart rate?? do I need any other divice?? can it be the iphone?? Also the speed only track the average speed – can I track more with some software for iphone?? also the cadence doest work at all with the vivosmart, is there any other device that would work, or iphone?? If I buy a ANT will it work all and track my exercise

  144. simon

    just bought a speed sensor – is there a preferred direction to install on the wheel. Looking at the instructions it seems they fit it the other way round than the photo in the review ?

    • What other way would you install it? I’m not sure I see any difference between what I’ve done and the manual?

    • Paul S

      I can’t imagine it matters. It’s just counting rotations, and it shouldn’t matter which way it’s rotating, since you’re not going to go backwards on a bicycle. Just try it and see if it works.

    • Paul S

      Well if you put the sensor on the top of the hub, you could wrap it around with the “tail” forward or the “tail” backwards, so that “GARMIN” faces one way or the other. On my MTB, with the sensor mounted on the front wheel, I can read GARMIN right side up. It looks like GARMIN is the same way on your rear wheel. If the manual shows otherwise, then the orientation doesn’t matter, since mine works and yours works.

    • simon

      you could install it with the LED to the non-drive side….ie 90 degrees to what you’ve done. Agreed it ‘might’ just be counting rotations, but if it’s anything like the footpods then they do something more complicated than that ?

      just a thought

  145. simon

    ^^^^^^ 180 degrees obviously 🙂

  146. Tipo Gemma

    Does it matter whether the speed sensor is mounted on the front or back wheel.
    I guess the front wheel should be better as the distance is shorter to my Forerunner.

  147. simon

    there are a few comments on the garmin forum that people get better reception (no dropouts) on the front wheel so no reason not too…..obviously you won’t get speed if using in a conventional turbo trainer

  148. Triweaver

    Do you have to order the Quick Release kit for the 920xt or will the one with 910xt work?

  149. Stu21

    I have just added the Speed/ Cadence Combo to Road Bike.

    The Edge 510 detected both no problems, and auto calibrate wheel size..

    Only issue is as soon as I get over 50 km/h The Heart Rate Readings on Edge 510 go up to 254.
    Never had an issue with Faulty Heart Rate readings ever!!!!
    Once I get under about 45, Heart rate does the big drop back to where it actually should be.

    Can see it easy on Strava, when you analyse a segment ?

    Doesn’t happen that often, but stuffs up the Ave and Max Heart Rate for ride

    Any Ideas ?

  150. CycloFeed

    Any idea if this set up works with Magellan or Mio 105 HC unit at all? I see the 505 doesnt support separation of the sensors but has the 105 been tested since this article do you know? Thanks

  151. m/v

    Is Mio 505 still not compatible with this new magnet-less sensors after the V4.1 software update?

  152. Anthony

    Hi DCRainmaker,

    First of all, thanks for your fantastic and extremely helpful reviews. I’m a duathlete (running&cycling) and would like to ditch the Polar for Garmin devices. I’m currently using a CS500 coupled with an RCX5 GPS. Would the Forerunner 620 with the bike sensors suffice as a single device (at least until I can afford an Edge 1000). What kind of functionality would I lose?



  153. Per M


    for once I didn’t check your reviews first before I bought the cadence sensor today.
    I thought it would work with Forerunner 610 as it’s printed on the box.
    FR 610 didn’t find anything to pair with but I wasn’t sure the sensor was active so I tested with Endomondo (Sony Xperia Acro S, ANT+ compatible android phone). Worked.
    Then I tested on my Garmin FR60 and Forerunner 50 (oldie). They also worked.
    (The firmware version in FR60 is 2.70.)

    On the side on the box it’s printed “Edge 1000, 810, 800, 705, 510, 500, 305 Forerunner 910XT, 610, 410, 310XT, 305, FR70, FR60”
    (Garmin bike cadence sensor, model 010-12102-00)

    • Hi. I would like to ask about the endomondo app with this sensor.
      Will it use gps for the speed or the sensor? How will you calibrait for the wheel size? And does it put live cadence? Thanks so much.

  154. Tiddle McGee

    I have an Edge 510. If I use a combo sensor to detect speed (no cadence magnet) and the new dedicated sensor to detect cadence, will that work properly? My impression from reading the above is that it will.

  155. Terry

    Hi, not sure if this is covered elsewhere nut scanning the comments I didn’t see this question. I have been told that the garmin 810 calculates speed from gps, if that is the case, is there any real need for a separate speed sensor?

    • Paul S

      With no sensor, the Edge 810 calculates speed/distance from GPS. When there’s a sensor, it uses the sensor. It’s more accurate to use the sensor, since the resolution of counting wheel revolutions is about 2 meters, while GPS accuracy is rarely better than 3 meters (and random), and GPS lock can be lost (in dense foliage, in cities with tall buildings, etc.). As a bonus, for free you get “3D” mode, since the sensor is counting revolutions so it follows the topography you’re traversing, while GPS distance usually ignores elevation gain/loss.

  156. Padmedamo

    Was looking for a fix to my Suunto Ambit 2s pairing woes above, which I didn’t find (above or anywhere). Since I managed to nail it…

    Whereas the old GSC10 combo speed/cadence sensor could be paired as a single ‘bike pod’, these are two separate pods. At least in my case the speed sensor/pod could be paired in the same way (I selected one of the free bike pod slots since I am still using the GSC10 paired as ‘bike pod 1’ on another bike). However, the cadence sensor/pod MUST be paired under ‘cadence pod’, not as an additional bike pod. I also wasn’t able to pair it whilst the bike pod was active; but, once I removed the speed pod to a safe distance, the cadence pod paired first time. TBH its possible the cadence pod WILL pair with the speed pod active but I removed it after a couple of failed attempts.

    Can’t comment yet on the accuracy compared with GSC10 (which was excellent)…

    • Alistair

      Any updates on how you feel about these pods? I’m awaiting the arrival of my 2 s and wanting to choose between the old GSC 10 and these two news ones? What are your preferences?



  157. Maz

    Hi DC Rainmaker, thanks for the excellent articles! I have a low-tech spinning bike at home that I use along with a Scosche Rhythm + HR monitor and my Garmin Forerunner 405 (it’s an old watch but I still use it). I’ve been desperately trying to get a cadence sensor to use with my Forerunner 405 and am failing miserably. I tried the Wahoo RPM which did not pair with the Garmin 405, and also tried Garmin’s GSC 10 which did pair with my watch but I couldn’t get the magnets on properly onto my spin bike because there was just no way to align both magnets properly at the same time.

    I noticed that the table you posted in this article says that Garmin’s new combo speed/cadence sensor will pair with the Forerunner 405. When I emailed Garmin themselves about what pairs with the Forerunner 405 they said only GSC 10 works. So are you positive the new combo sensor would work with the Forerunner 405? If you says it will, I will give it a shot.

    Thanks in advance!

    • Paul S

      The GSC-10 is the sensor that’s called “speed & cadence combo sensor” in the table above. Garmin doesn’t have any other speed/cadence sensors so far as I know. The table says that the new sensors (separate speed and cadence sensors) won’t pair with the 405.

    • Maz

      Thanks for the clarification Paul!

  158. John


    really like your reviews (bought TopTop multisport after reading your review last year).
    Im looking for speed\cadence. right now Im using Iphone 5s with wahoo rflekt+, wahoo blue HR monitor and also pair bluetooth headphones to my Iphone, which means that three devices are connected to the iPhone via bluetooth.

    as I can see I have 3 options
    1) Wahoo RPM – bluetooth (and continue to get my speed reading from the iphone)
    2) garmin – try to pair this set to the rflkt+
    3) cheap spped\cadence from Ebay like coospo – bluetooth.

    Would love to have a recommendation

  159. John

    Hi there. I am using a Garmin Edge 500 computer & the GSC10 speed/cadence combo sensor. It has been working just fine for the last 8 weeks since I bought it brand new but now, speed readings are not being picked up. Cadence readings are being picked up. Through a process of elimination I have checked that the GSC10 battery has sufficient power, that the spoke magnet & pedal magnet are both in the correct position where they need to be as per installation instructions and that the Edge 500 unit itself is working perfectly & up to date. With my bike on a work-stand I press the RESET button on the GSC10 & when I spin the pedals I see the cadence is reading perfectly on the Edge 500 and the RED LED light flashes on the GSC10. However, I do not get a GREEN LED light flashing corresponding to the GSC10 speed sensor & hence no speed reading on the Edge 500. I read here on your webpage that there is a new speed magnet I can put around the hub of my back wheel. I also see that these new magnets can be paired with my Edge 500 which is great. Before I purchase them can you assure me that it will work? I need speed & cadence for my training as i am being coached & my coach needs to analyse my data by viewing my rides on “Garmin Connect” after i upload each ride. Finally i believe that the speed sensor has got quite wet recently with the wet roads, rain showers and washing the bike and this may have damaged the speed senor – so is this new hub magnet more waterproof? PS My garmin edge 500 settings are set to “Speed/Cad Sensor”.

    • I had this trouble, it turns out mine had the same trouble until i figured out that my bike handle bars, mounts and aero’s were blocking the signal or it was too far away. I find this very annoying. I move the unit from middle of aero’s to the handle bar center and it worked. i dont want it there, but it wont work another 8 inches up my aero’s!!

      Someone suggested a higher mill amp battery in the sensor but i dont know if this is possible.

    • Lids

      Did you ever fix this problem? I’ve got it as well. My Edge 510, which was working perfectly until I let the battery go completely flat “lost” the bike profiles. When I recreated them and paired it with the GSC10 on my road bike it also just picked up cadence and not speed. Don’t think its positioning as I can put the bike on a bike stand and hold the unit close to the sensor and still not pick up a speed signal. Contacted tech support at Garmin and they suggested reversing the polarity on the GSC10 by taking the battery out, turning it upside down and replacing it for 15 seconds. This didn’t work for me.

  160. andrew grindrod

    sorry this might be a very newbie sort of question, but do you have to manually enter the wheel size – thinking how speed and distance are calculated. – intending to use on road bike and MTB

  161. Jakob

    Hi Ray,

    I have been reading around to find out how to perform the manual calibration of the speed sensor, but without luck so far.

    Do you require a Garmin Edge to manually calibrate the speed sensor for my wheel size?

    Reason for asking is I am looking to connect it to my indoor trainer equipment, primarily for use with TrainerRoad, but I don’t own nor do I plan to own any Garmin Edge. Still, calibrating the sensor for my setup is sort of a requirement.



    • Paul S

      The sensor is never calibrated. All it does is count wheel revolutions. The conversion to speed/distance is done by the head unit, whatever it is, so you enter the wheel size there.

  162. Jakob

    Hi Paul S, Thanks for your quick reply. When you say you enter the wheel size “there” at the head unit, do you mean that there is an interface for entering the wheel size right on the unit itself?

    • Scott Nickell

      Jakob: you don’t plug it into the unit itself. In TrainerRoad you define the wheel circumference in the user profile under Bike Settings.

    • Jakob

      Hi Scott, Ah, that was what I was looking for, excellent. Thanks! Makes perfect sense letting the sensor just count the revolutions and leave the rest to the software.