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4iiii’s Introduces $399 Power Meter, Precision: My First Ride With It


4iiii’s has kicked off what will be a frenzy of power meter activity here at Interbike this week.  In doing so, as the post headline implies, they’ve jumped onboard with the plans to further drive the price of power meters down into a larger cycling audience.  They’ve introduced their latest product – Precision – which is their power meter offering that  sits at $399US (with dual left/right sensor support at $749US).

I’ve had a chance to ride with the units on a ride, as well as to spend considerable time doing everything from installing the unit myself to calibration of the sensor.  And, I did this all on a decked out power-meter laden bike.  Just me, Precision…and three other power meters.  Of course, a single data point of one ride doesn’t mean the product will be flawless (or failure bound).  Rather, it’s just a first glimpse at things.  And with that, let’s begin the walk through.

A Brief Overview:


The Precision is in many ways a lot like the Stages Power Meter, except with two key differences: It can be installed yourself, and it can be installed on both crank arms (versus just left-only with Stages).  Well, that and being about 40% cheaper (or more, depending on how you purchase it).

Precision is all based around these two tiny pods.  These prototype pods are slightly larger than your average running footpod, and the bulk of the size is really dedicated to the CR2032 coin cell battery contained within.  The actual innards of strain gauges, accelerometers, and ANT+/Bluetooth Smart communications chips are quite small.  However, the next prototype versions (and production versions), will significantly reduce the sides, effectively eliminating the sloped section (which currently contains additional wiring connectors for development logging capabilities).


These pods are then installed on the inside of your crank arms.  You can install it in a left-only configuration, as seen lately on a number of power meters (Stages Power, ROTOR Power LT, Garmin Vector-S, Polar Keo Power Essential), or you can install it in a dual-sensor configuration.


In a dual sensor configuration you install it on both the left and right crank arms.  This nets you a complete picture of your power output (watts), and thus minimizes issues with left/right balance.

These pods are installed by you (yes, you) using a calibration tool that’s included inside the kit.  The pods are basically cemented on.  You can remove the pod from the crank arm, but the process does destroy the pod.  However your crank arm would be fine (Tip of the day: Would likely be cheaper to just buy a new crank arm).


Precision communicates with your head unit using either ANT+ or Bluetooth Smart.  So it’s just a matter of which protocol your head unit uses.  It’ll transmit all your standard power meter metrics on both sides, but I’ll dive into that a bit later on.


Now those that have followed the moves and players in the industry may find it interesting to know the person behind 4iiii’s Precision: Keith Wakeham.  Those with good memories will remember it was Keith that about 2 years ago published plans for his open-source power meter design, which was a DIY approach to building a power meter.  While that unit has no resemblance to today’s Precision, the learning from Keith’s efforts no doubt contributed heavily to it.  Prior to that, he worked in the nuclear industry on strain gauges.  4iiii’s snatched him up last fall and they’ve been plugging away since.  The power meter world is indeed a small place.

With that, let’s begin installation.

Installation & Calibration:

I want to first point out that the tools you see here are NOT consumerized yet.  Which means that while the process is final, the actual tools that you’ll get in the package will be smaller, more user friendly and generally look ‘pretty’.  They haven’t begin the manufacturing of those tools yet, since that’s about the last thing you’d do in terms of manufacturing.

And, despite how this process looks – it was actually silly easy.  You can complete it in less than 5 minutes…at most.

For the installation I completed it on a single crank arm on the desk of a Fairfield Inn hotel.  No fancy workbench was needed, and while I effectively had a nuclear engineer guiding me through it – there’s no need for that either.

Every kit comes with these tools (or again, a variant of them).  they are:

1) A clamp
2) A two-part epoxy
3) A tool to squirt out the epoxy
4) A guide to fit the pod to the crank arm.

You can see all of them below:


To begin, you’ll need a crank arm, or two, depending on how many pods you’re installing.  You’ll be using this little tool that helps to align the best installation spot for the pod on your crank arm.


The tool then holds the Precision pod in a perfect little grooved area.  The pod’s backing is covered with a protective tape.


The first step is to take a pencil and simply mark the area on the crank arm where the pod will go.



We’ll then use the included sandpaper to lightly sand this area, which helps to increase the ability for the glue to hold.


Then we simply clean it off with a couple of swipes of swabs, which removes the sanded material.  There’s also one more swipe with a gauze pad.


Now we’re ready to add a tiny little bit of glue.  The glue gun will automatically mix the two epoxy’s perfectly, without any air bubbles.



You don’t need much epoxy.


You’ve got approximately 20 minutes until the epoxy starts to set.  So you don’t have to worry about rushing.  Heck, you could even go out and run a fast 5K.

Next, you’ll go ahead and remove the protective tape backing on the unit and place it in its tray:


Then, simply flip it over onto the crank arm.  The tool settles into the pedal attachment area, keeping things snug.


Finally, we add a clamp.  The clamp has a little rubber piece on the opposite side to protect against scratches.


You’ll leave the whole rig alone for 6 hours.  Depending on the temperature outside (if hot), it can be a bit less.  But really, just leave it alone.  The photo you see throughout the post with the crank arm by itself were all taken the morning after with the completed unit.

Now, the piece I didn’t get to cover here was the calibration.  The calibration will use a separate tool that has a ‘S’ type load cell in it.  The tool comes in the kit, and is only used to calibrate.  The tool will have three little grooves where you can hang a weight from it.  The load cell can determine the weight within .01% accuracy, which then allows them to further calibrate the power meter.  The user will place the weight at each of the three groves briefly, which in turn provides just enough differences in torque to properly calibrate the unit.  The whole process should only take a couple minutes at most.

The unit is smart enough to determine whether it’s assigned to the left or right side, based on the torque and direction.  Additionally, it’ll use private-ANT to pair itself up to the secondary pod if you bought that.

Connecting to a head unit, usage:

The 4iiii’s unit connects to head units using either ANT+ or Bluetooth Smart.  To start, we’ll go with ANT+ since it’s the most dominant in the cycling world.  For that, I just used an Edge 810.  Of course, you can use any head unit that supports the power meter protocol.


Next, I’ll go ahead and have it search for a power meter to pair, where it’ll find the 4iiii’s on my bike:


Next, to prepare for a ride we’ll go ahead and calibrate it by setting a zero offset, similar to other power meters.  This is typically done within the settings menu of the bike profile.


From here, you’re pretty much ready to go.  While riding you’ll get total power displayed, as well as individual left/right power (assuming you purchased the dual sensor package).


All of this data is recorded by your head unit for later analysis in whatever apps you normally use, like Training Peaks or Strava:


Now, if you’re more of the Bluetooth Smart persuasion, you can pair with that as well.  For example, the Polar V650 pairing with the 4iiii’s unit.  Alternatively, you could use the Wahoo Fitness app on the phone which allows you to more easily send data to all sorts of 3rd party partners.

From a usage standpoint, it’s very similar to other power meters.  You’ll complete a zero-offset at the beginning of a ride, but beyond that it’ll pretty much take care of itself.

Looking at the pod itself, there will no doubt be very valid questions on the adhesive and ensuring that it stays where it should, and that it isn’t impacted by weather or the accidental slip of the foot.  All issues I’ll definitely be looking into as part of my in-depth review.  In talking with 4iiii’s, it’s an area they’ve spent a lot of time in with respect to the specific glue chosen.  Out of all the areas that they talked about where things weren’t quite finalized/firm yet, this was the one area they seemed very sure of.

The Test Data:

VIRB Picture

I started out this morning prior to sunset. Given my time constraints of the day I went with a single 40-minute ride for today, along with a secondary short section on the trainer.  The ride was done on park roads in Lake Mead National Recreation Area.  The same place I often do testing of devices when I stay in Vegas.  The route is also used by a number of triathlons too.

Here’s the illustrated version of the power meters used in this morning’s tests:


As you can see, I’ve got the following units on the bike.  We didn’t use my bike due to not quite having enough current generation prototype units to part permanently with.  I did however bring my PowerTap to install, and we unboxed a set of Vectors that we installed on the bike together.  The SRM and 4iiii’s unit was already in place.  So I had complete control over two of the power meters, and they had prepared the other two.

SRM: Crank spider based
Garmin Vector: Pedal based
PowerTap G3: Rear wheel hub based
4iiii Precision: Left/right crank arm based

All of this data is then fed into two different spots.  First is to conventional cycling head units, in my case the Garmin Edge 1000 and 810 for the Vector (1000) and PowerTap (810) data.  And two additional 810’s for the SRM and 4iiii’s data.  I have a few of them in my collection.  These units all act as ‘backup’ of my data.

Second, it’s also fed into the much more important tool, the North Pole Engineering WASP ANT+ data consolidator.  It allows me to seamlessly record everything as one coherent and complete picture.  This removes the complexity of matching up files afterwards.  The WASP then transmits to the phone via WiFi, where the data is recorded in real-time.


Without further ado, here’s what that ride data looked like at the ‘50,000’ ft view:


I excluded the SRM data, since for whatever reason the WASP wasn’t collecting that stream.  So I need to manually re-process and normalize that data from the backup data files, which I’ll do later today.

Looking at the data however, you see at a high level things trend fairly well.  You see that the Precision is a bit lower than the others.  In talking with Keith, we saw that beforehand and believe that’s due to some minor drops he’s seeing with that particular pod, thus causing a lower overall value.  You see one unexplained spike towards the very end, oddly enough as I was coming into the parking lot coasting.

Now, let’s dig a bit deeper into the differences between them.  After all, I’m more interested in where they differ than where they are the same.  This is where it’s important to remember that no two power meters will read identically – no matter how hard you will try.  There are inherent accuracy limitations (usually 1%-2.5%), along with differences in placement.  This means that a PowerTap will inherently read a lower wattage than a Garmin Vector – as Vector is closer to the source of the power (you).  In order to make this graph make sense, I’ve tossed out those last few seconds of the ride (since that would hugely skew things and was an outlier).

First, here’s all three smoothed with a 10-second rolling average.  I’ll use that as the baseline:


Next, we’ll look at the CP, which helps us to identify how they trended over chunks of the ride.  I used Golden Cheetah to create this.  Below you’ll see all four power meters (including the SRM).  You’ll see that by and large they are pretty similar.  We see slightly more variation at the top-end, with the 4iiii’s unit being low throughout (as expected from earlier notes).


You can see down at the bottom the average power values (be careful of looking at that), along with the max power values for a few different timeframes from 10-seconds up to 8-minutes.  This helps a bit to make those values more relatable.

Finally, let’s look at cadence.


Eek.  As you can see, this is a bit all over the map.  And, to be fair to them – they expected that.  The noted the night before the ride that they had just switched the component doing cadence to what they’ll use in the final production version and they hadn’t had a chance yet to optimize the algorithms there.  Of course, in most power meters cadence is a key factor in determining power.  Yet, I’m not as concerned about this particular component, only because accelerometer based cadence is at this point well understood in the cycling industry.  So it’s mostly a case of them optimizing their new component algorithms as many other companies have recently done (Garmin, Stages, Power2Max, Polar, Brim, etc…).

I also did a short 9 minute test on a trainer, just to get some ‘smooth’ data to see what it looks like.


I’ll be uploading that data a bit later today.

Oh, and for those wondering about that gap in the middle around the 30 minute marker on the outdoor ride?  That’s when the derailleur decided to try and establish a close and continuing relationship with the spokes on the wheel, thus injecting the chain down in the gap between the cassette and the spokes.  It wasn’t pretty undoing.

VIRB Picture

You are welcome to download the raw data for your own analysis, all of it is located here.  You may publish your own analysis of the data, though, I do ask you link back to the source post here.  If you want a simpler version, you can just look at the Garmin Connect file online here.

Misc Details & FAQ:


Below are some random details and facts, along with what I suspect will be the most common questions.

Crank Compatibility (general): More or less anything with a flat surface.  Conversely, I couldn’t however use my ROTOR crank arms on another bike, because those arms have grooves that the gauges wouldn’t be able to measure correctly.  They’ve tested the last three generations of the Shimano 105, Ultegra and Dura-Ace cranks, as well as the Deore XT.  Within SRAM, the Rival OCT, and then on the mountain bikes the X9.  Within FSA the Energy crank arms.

Carbon Cranks: Thus far their testing “looks good” according to them, but they’re continuing to test cranks there.

Crank Length/Width: There are no inherent issues here with larger or oversized cranks.  The only potential tricky area would be if your crank arm has some sort of weird bending or shaping that leave it no flat surface.  For example, on the VERVE Infocrank (another power meter), it curves around and thus there isn’t any flat space to mount the pod. But that’s extremely rare (and likely not an issue for anyone in the world except me).

Chain and frame clearance: You’ll need approximately 9mm of clearance for the final production pod.  Of course, where you install it will change the clearance required.  Typically there is more clearance near the bottom bracket, and less clearance near the end of the crank arm.  from a length standpoint, the exact length is still being finalized and will roughly be in the range of ~28mm wide by ~40mm long.

The Calibration Kit: This is sorta the funny special sauce.  This is used to calibrate the sensor with hanging weights and a ‘S’ type load cell that will attach to your crank arm.  The kit by itself costs $100, whereas it’s included in the $399 price point (but not the $349 pod package).

Temperature Compensation: The unit utilizes “active learning temperature compensation”, which is a fancy way of saying that they record zero offsets at different temperatures and slowly build up a database of different temperature compensation points.  This will be triggered by you, and helps 4iiii’s get around the fact that the install isn’t being temperature calibrated at a facility elsewhere.

Battery Life: The unit utilizes a CR2032 coin cell battery – the same as most other sensors on the market.  You can find it for a couple dollars easily around the world.  4iiii’s claims a battery life of about 200 hours. Obviously, I’ve not yet had a chance to test that.

Weight: Each pod weighs 10g. I have not yet personally verified this, though I have no reason to doubt it.

Weatherproofing: IP65 rated, which is slightly better than IPX7, as it protects against water jets versus just immersion.  Thus allowing you to spray down your bike.

ANT+ Connectivity: The unit is able to transmit via ANT+ to any other standard cycling head unit that supports the ANT+ power meter profile.  Today that’s every Garmin cycling and triathlon focused device above $200, the PowerTap Joule, Timex Cycling and Triathlon units, Magellan Cyclo and Up units, and many others.  The unit supports sending the following metrics: Total Power, Left/Right Power, Torque Effectiveness, Pedal Smoothness.  Of course, you must have a power meter head unit that supports those specific metric types.  It broadcasts both Bluetooth Smart and ANT+ concurrently at all times (no impact on battery).

Bluetooth Smart Connectivity: The unit is able to transmit via Bluetooth Smart to any cycling head unit that supports the Bluetooth Smart power meter profile.  Right now this is essentially the Suunto Ambit3, the Polar V800 (later this month), the Polar V650 (October), and then smart-phone driven apps and devices like the Wahoo RFLKT.  The unit supports sending the following metrics: Total Power, Left/Right Power, along with some similar metrics for torque effectiveness.  Of course, you must have a power meter head unit that supports those specific metric types.  It broadcasts both Bluetooth Smart and ANT+ concurrently at all times (no impact on battery).

Pricing: The unit is priced at $399US for one pod (left or right only), or a dual option at $749US (both left/right pods).  You can upgrade later for $349US with the PM-100 (pod without calibration kit).  Pricing outside the US is TBD.  The SKU name for the single pod is the PMK-100 (with calibration kit), and the left/right secondary pod is PM-100.  The acronym comes from: : Precision Module Kit.  Note again that you can install a single pod on either side.  If a friend/shop/etc has the 4iiii’s calibration tool, then you can simply get the cheaper $349 SKU (PM-100) and use their calibration tool.

Shipping Date: 4iiii’s states they will begin shipping this year (Q4 2014).  I should point out that in the 7 or so years I’ve been writing this blog only one power meter company hit their initial timeline estimates: Stages Power.  They did so by having a similar plan as 4iiii’s in terms of waiting until the ‘last minute’ to announce.

Some summarizing thoughts:

VIRB Picture

At Eurobike, virtually every industry person asked me what I thought of left only power meters.  My response was basically the same to everyone: I believe that left only power meters are in some ways a temporary thing.  While Stages set the precedent, they did so not just in data collection location (left), but in price.  But despite common thinking they didn’t put the price elevator at the lobby, but rather about 20-30 floors up from where their elevator can go.  For now, that elevator has sat there and Stages has raked in the dough and outsold other power meters in some cases 10-20 to 1 (in talking with many local bike shops).

You saw other companies join in the left-only ‘thang’ by introducing their own variants at cheaper and more accessible price points.  Then we saw a new entrant – Watteam’s PowerBeat – jump into the fray with promises of a $499 power meter for next summer.  Meanwhile at the higher end, we’ve seen the price of Garmin Vector temporarily drop $400, while also introducing cheaper left only options.  And we’ve seen SRAM’s Quarq restructure prices as well to lower them.

While some might think the end-goal here is a $500 left-only power meter, they’d be hugely mistaken.  We’ll also be seeing more entrants in the lower-priced but higher data quality market by time the week is over, which starts to create a cyclical effect.  Left-only units will drive current prices lower further, and left/right will take its pricing place.  Then the cycle will repeat.  It’ll repeat for the simple fact that companies like 4iiii’s and Stages have the manufacturing cost basis power to drive those prices incredibly low.

Of course, just like Stages – that’ll depend heavily on these new entrants (such as 4iiii’s) having a product that’s accurate across a wide range of riders and equipment, and a wide range of environments.  And I suspect also like Stages, they’ll too have some initial teething bumps along the way.  All power meter companies do.

My testing showed initial promise, not perfection, but promise.  But it’s just that – a first ride.  Once I get v2 prototype units on my bike I’ll be able to develop a much bigger bank of data to work from and establish whether or not the Precision and their self-install method is a viable option in the market.  I’m actually less concerned about 4iiii’s ability to technically resolve any outstanding issues.  It’s a beta product, if it was production they’d be selling them tomorrow.  In my discussions with them about their outstanding technical issues, it felt to me like they had a very clear grasp on what had to be done, but it was more of a timing thing.  They had been focusing on OEM installations (i.e. from a crankset company), and then changed gears to be self-install – so their attention got diverted a bit in the last month.

I also don’t have any concerns about manufacturing of Precision’s pods itself – 4iiii’s has a long history in manufacturing already.  My only concern is that I don’t quite think they’ll get all this done by the end of the year.  I suspect we’re likely looking at January-March of next year.  Though, I suppose there’s likely not a lot of difference riding-wise between December and February (no matter which side of the equator your on).

For now though, it’s definitely an exciting time to be in the power meter market.

With that, thanks for reading!  If you’re looking to burn a bit of time, here’s all my Interbike 2014 posts packed full of sports technology items.

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  1. Joshua Parks

    Now here we go! You were hinting that pricing pressure was coming. Watching your reports from Eurobike 2014 we saw some movement but not the big news that this represents – sure the Garmin single only announcement was important…

    Spot on analysis on the pricing side. Bravo. Let’s see what happens – I’m particularly interested in seeing how Stages responds. And a bit less to see how Garmin and the more established manufacturers.

    Will be an interesting year, thanks for the head’s up.

    • mike

      Anyone ever heard of Dyno Velo? Power meter that is supposed to cost less and fits into the spindle of a hollow crank, even a Shimano Tiagra. They have a youtube video if you type in dynovelo power meter.

      This one you just tighten into place. You can sign up for notification as well.

    • Darwin

      Stages has trouble producing enough units to sell. They need to figure that out. I also see a lot of complaints of the unit falling off cranks.

  2. Tim Nordberg

    I was almost too distracted by the Apple Watch announcement to read this whole post…

    Very intriguing, I always end up with an epoxy mess whenever I break that stuff out, but I guess with a little careful application one could be less messy :)

    Wishing I could find a good source for an alternate Felt Rear Brake for my B16… Most reports I’ve seen imply something in this 9-10 mm range would likely interfere with the brake unless swapped for a special TRP model (which seems really hard to find).

  3. Ge Wang

    Great to see more choices of power meter, I think this will be cheap and popular as a meter soon


    I look forward to the full review!

  5. Tyler

    I always wondered why no one was doing power meters with a simple wheatstone bridge load cell.
    These things cost less than $50 (for wired version).

  6. Luke

    …and there are no comments because everyone is watching the Apple keynote.
    This sounds pretty cool to me, a great price for both sides…

  7. Mark Liversedge

    Cool — its great to see companies shaking things up.

    When you say removing destroys the pod, is there any re-use so can switch cranks or is it a whole new purchase ?

    PS: I know you’re big time Tri, but no socks, that breaks the Velominati rule #27, tut-tut ! (link to velominati.com)

    PPS: thanks for the GC mention !

    • You could save the battery, but the rest of the power meter would be wrecked when you remove it from the crank arm.

    • Juan Zorrilla

      Velominati rules are for roadies, they seem to hate triathlons. Although rule 5 still applies to everybody.

    • Mr Nofish

      Velominati is a big circle jerk as far as I can tell. Some say the rules are sarcastic, but I can only take so many artisanal graveur posts (or equally irrelevant impoverished 1% stuff) before I call bullshit.

      Oh BTW if you’re reading this and they made you think some bikes are not hand built, let me tell you the Velominati either have no idea how bikes are manufactured or worse.

    • H M

      If you were more versed in cycling history you would realise that no socks is cool.

      Especially for trackies like me….

      Google a picture of Forstemann racing
      My suggestion for the next #aeroiseverything video would be long socks vs short socks vs no socks . . . The track sprinters know what they are talking about

    • Mark,

      Sell the crankset or crank if you want to change and buy a new unit rather than destroy the pod.

    • Si


      These guys have it right: link to vulpine.cc

  8. Sebastian

    Wow – this is so cool and exciting!!!

    Finally my needs have been heard of what I want from a PowerMeter. Invisible, flexible, affordable. Wow.

    Love to see how this evolves after people tested this for 6 months. I am more of an early adapter.

  9. Chris

    Why left side only? and not right side only?

  10. Chris Pugrud

    Good article and it will be interesting to watch. Personally I’m feeling pretty burned by 4iiii’s continued lack of Android support a year after they said they would support it for the Viiiiva.

    That said, as long as I don’t have to borrow my buddies iPhone for a firmware upgrade, I’m very interested.

  11. Looks great, but still tough for those of us with aluminum Campagnolo cranksets that have a non-flat surface on the backside of each crankarm. Seriously, not all of us who use Campy are made of money!

    • Luke

      Ugh, just checked my cranks and they’re not flat on the back…
      I don’t suppose that a crap-ton of the epoxy to flatten out the divot in the crank wound work?

    • Mr Nofish

      I don’t think so, the problem with attaching to a non-flat (i.e. grooved or whatever) surface is that this leads to a concentration of tensions. Filling the grooves with epoxy wouldn’t change that.

  12. Zircon

    Is there a particular reason all the left only options gravitate towards the low price segment? From my understanding, the high prices of power meters is due to the need to recoup R&D costs, not the actual cost of the meters. If you can recoup R&D at a low price for left only, surely you can do so at a slightly higher price (for the extra pod) for L+R?

    • Josh Potter

      This can be used as L, R or L+R.

    • chukko

      My guess would be that companies are trying to sustain current price model as long as possible. When Stages came with sensor on the crank – left only option was a good compromise – justifies the price below everyone (hallf of the product for half of the price) and avoids solving problems with clearance on the right (and price of delivering two cranks).
      Dropping the cost of L+R would unnecessarily undercut their revenue – as minority who need L+R can pay premium for that.
      The same applies for new entrants who try shatter the whole market.
      With left only they get the product to the masses – and with L+R increase the revenue. Seems close to a win-win.

  13. Chris

    Awesome! The prices just keep dropping and dropping. I can’t resist for much longer…

    Did you gather during your meeting whether a left only pod will be available without the cal kit? For example, if I were buying two left only units, one for one bike and one for another?

  14. matt

    great review as usual, sadly i jumped on the Stages and Garmin power meter bandwagons a long time ago. Also, point of clarification, while YOU might be able to head out and run a 5K before the glue dries, there is no way in hell I would ever get back before the glue had long since set. Must be nice to be fast!

  15. Kurt

    Interesting product. So for 750$ I can install a power meter on 2 bikes?

    • ed rusk

      I was thinking the same thing: buy a left-only for both bikes so i don’t have to switch pedals or cranks. once I begin using power, it shouldn’t matter if i have left-side only on both bikes, in my simplistic thinking. i could still measure progress and effort, regardless of it being left-only or LR. Right?

    • That’s 100% correct. Pod + cal kit is 399, and additional pods that can use the cal kit are 349. You can feel free to upgrade your two left only later on to L+R if you so chose for the same 349 price.

    • Marin

      You could do left-only on one bike and right-only on the other with the option to combine them and run left-right on either if they have the same cranks!

    • Sebastien Gagne

      I think the ordering the kit you can do both with left only since each pod will detect which side it’s on.

    • Correct. The single pod can be placed left or right, or can be used in tandem if you put the crank arms together.

  16. Drew

    And this is why competition & the free market are a marvelous thing! Pretty soon we will see dual sided power for under $500. Maybe not this year, but as soon as someone can find a way to do it for less, they will put the rest of the industry out of business.

    • MD

      Great for all the people working at all the other companies….Yeah….Woo free market… If anything its the free market that has kept them so high because the companies are seeking high profits !

  17. Stuart

    I’d like to ask the guys at 4iiiii, the battery cover, how is it fixed to the body of the unit, tabs or screwed down? The reason I ask is I went through 4, yes 4 Stages units due to the poor locking tab design, where moisture would get in, battery’s short, unit gets returned, repeat. A screw down battery cover would solve this issue.

    • The battery cover currently twists on, similar to our Viiiiva. I’ll pass your concerns on to our engineers.

    • Stuart

      Have a look at the Garmin Battery cover on one of their HRM chest straps, screws in, totally waterproof.

    • Honestly, the system that they’re using and used on Viiiiva is comonly used on the majority of ANT+ and Bluetooth Smart sensors in the market. It’s different than Stages (which, I agree is finicky, having just replaced a battery tonight). I really haven’t seen any issues with breakage or water on the non-Stages implementation.

    • Bill

      And the Garmin is totally worthless when you can’t get the screws out. Happened to me twice.

    • Craig Maddox

      Out of interest how many hours did you get? I also changed my last night and had not done more than 60 hours (I was using an Energizer battery).

  18. Duane Gran

    This is a game changer and I’m pretty enthusiastic about it. Hearing that Keith Wakeham is involved, after reading his thorough work in building crank-based power meters, only furthers my enthusiasm. My only wish for this would be an option where my local bike shop can stock the installation materials and buy the pod individually. As I look over the install steps I’m sure I could do it myself, but I doubt I would ever need to do it twice and have need for the whole apparatus.

    • They can do that! Both the pods and calibration kits are also available separately, so your local shop would only need to buy one calibration kit and as many pods as they want to stock.

    • Mr Nofish

      The choice of a price point is a step forward, but a game changer? how?

      Since the system allows a later upgrade, the kit could indeed be used twice (although I wonder what would happen to the glue in the meanwhile), and as a person owning a vast array of cycling specific tools, I’m inclined to think that having the LBS do the job would probably cost as much if not more than the kit.

    • H M

      I work in an Engineering department and brought in some lifting plates to work to weigh so i have two ~10kg plates weighed to +/- 0.5g – could I just use these weights and save on the calibration kit ?

      (I bought the weights to calibrate my SRM but I would like to go wireless some point soon and your product looks pretty awesome)

    • The challenge is that the calibration tool has three specific grooved slots to measure the torque in three locations. You could use your weights with the tool however.

    • Duane Gran

      Fair enough, maybe it isn’t a game changer in terms of technology applied, but then they all come down to interpreting a strain gauge somewhere. I do think the big change here is a really attractive price and the right blend of manufacturing refinement and DIY. If it gets good reviews one will be hard pressed to justify paying for Stages. I do think the option to later upgrade the system to right/left power is a nice feature. A lot of the enthusiasm may be that power metering seems to be getting more affordable. Thank goodness!

    • Mr Nofish

      I see what you meant now – indeed affordable power meters have the potential to revolutionize how the masses train, although I have a hunch most will simply look at the numbers without really understanding what’s behind them, more or less like they do now for e.g. heart rate (the difference being that heart rate doesn’t really lend itself to pissing contests)

      Plus, as Ray often remarks, even existing power meter users often get inaccurate numbers because they don’t calibrate etc – and I get the feeling he is more than right from the numbers I sometimes see posted by PM users on Strava.

      Still it’s great thing for those of us who want to improve sooner and are willing to put the brains and the legs into getting better, faster – so most definitely not complaining!

    • We’ve made the kit idea simple enough for user install so we are hoping that there won’t be any shops or dealers pulling the wool over peoples eyes. Transparency in the install process is important to us.

  19. Brad

    May be a noob question that you have covered before, but how do left only crank arm (and pedal based for that matter) power meters not measure bumps in the road or bunny hops?

  20. Dan Morley

    awesome news! I really hope that it will be compatible with carbon cranks!

    • Our early testing has been positive. We need to evaluate each carbon crank on a individual basis to come up with recommendations on intervals to recalibrate. This is effectively a fatigue test where we monitor every cycle. Everyone’s layup and fatigue properties are different. We’ll be making recommendations in the coming months as we complete testing.

    • That’s good to hear. I have Oval carbon cranks now (think FSA) and buying an entirely new set of cranks really defeats the purpose of going with an inexpensive power meter.

    • We’re attempting to determine test order on carbon crank sets for fatigue testing. Oval Concepts or is it physically oval in shape?

    • Tom A.

      So…what you’re saying is, carbon cranks get “softer” over time?

      Oh…I can just imagine now people replacing their cranks because they got “too soft” and weren’t stiff enough anymore ;-)

    • Lars

      Hi Keith,

      Looks like a great product! And D.C.R, great first review.

      Could you elaborate a little on why you have to evaluate each carbon crack arm. What do you mean by “recommendations on intervals to recalibrate”. Please give the full technical explanation if you please.

      I am asking because I am wondering what would happen if I just bought a unit now, and glued it on to my SRAM Red carbon crank arm? Would it work in your opinion?


      PS. Where to buy in the EU?

    • RayG

      I assume, then, that layup and fatigue properties will also change with the year of manufacture of cranks with the same model name on the label. Keeping track of all of that could get complex.

    • chukko

      Were there any carbon cranks which failed the tests?
      Also – what would be the symptoms of such failures? Significant drops in measurement precision or anything else?

  21. dieter Neirinck

    Awesome evolution. At this price point, do you think power meters will become a standard option on new bikes, much like electronic shifting is finding its way to “standard bike component” status ? Would seem like a great way for a cycling brand to differentiate its offer: power meter included in high end and/or mid range 201/2016 models.

    • There’s a lot of talk in the industry on making units OEM. That was 4iiii’s initial plan actually for Precision, until they changed to be direct to consumer (a wise business choice, and one that I think is good for consumers).

      I think we’re close, especially since companies like 4iiii could still go the OEM route with the component costs being so low that it’d probably be appealing to major bike brands. But those brands really want to see this stuff in action first – which might delay things a bit.

    • Alan Cote

      The product/technology certainly looks intriguing, and I think your caveats about how the units perform after extended use is spot-on.
      Consumer-direct sales (only?) make me raise an eyebrow. This isn’t a wristwatch. While some portion of potential buyers will have no problem with the installation, many won’t want to be bothered with it or are incapable of removing cranks, etc. Coupled with the fact that many sales are driven by the recommendations of bike shops, makes me skeptical of the distribution model. Particularly for a product aimed at a broader swath of cyclists.

    • Sorry Alan, in this context I meant direct to consumer as opposed to OEM installs with crank manufs. They’ll still be selling through all regular distribution channels including bike shops.

  22. For the 4iiii’s that are monitoring this thread. Would this work on a steel crank arm that are used on Indoor Cycling bikes like the AC Performance?

    If not tested, I would be a willing tester…:)

  23. Tisztul_A_Visztula

    Does Ultra exist??? I guess it should be Ultegra,

  24. ken

    You wrote: “SKU name for the single pod is the PMK-100 (with calibration kit), and the left/right kit SKU is PMK-100.”

    Are both SKUs the same or is this a typo?

    Also, just curious… why does one have to affix the pod at a certain length of the crank? Given how clearance is different on different bike/crank combos, wondering what impact moving it forward or backward by a few mms?

    • Our SKUs are:
      -PKM-100: Precision + Calibration kit (MSRP: US $399)
      -PM-100: Precision module only (MSRP: US $350)
      -PK-100: Calibration kit only (MSRP: US $100)

      There isn’t any significant impact in moving the pod forward or back, but the closer it is to the bottom bracket the better the sensitivity. Our install tool will be universal, and will be somewhat adjustable to help position the pod where it has the necessary clearance.

    • Sorry, corrected the SKU name.

  25. Dave

    I could not use the Stages meter due to interference with the chainstay mounted break on my 2013 Madone. I suspect this device would have the same issue, as it appears to be at least as thick as the Stages. Any thoughts on whether a right only configuration would work?

    • Yes, a right-only install should work properly

    • Patrick

      i have the same bike/issue. from what i can tell this should have less trouble as the pod is not as long and is flexible as to where you mount it on the crank so rather than being fixed in just the right place to foul on the brake you can find a spot where the frame and brake allow clearance and put it there. so left side could well be possible too – i intend to check clearance on my bike. right side is obviously less desirable due to chainrings getting in the way.

      really hoping this is everything it appears, great work 4iiiis!

  26. Mr Nofish

    Given your final remarks about the price elevator etc, I am sincerely wondering why you defended the price points of then new units (even the least interesting overpriced left-only me-toos) against some of us in the comments.

    I understand your being friend with insiders and not wanting to piss them off but with your time being so limited it does seem a fair bit of waste spending it that way, now that your post is not just acknowledging what some of us had been saying, but went even further.

    • Because the existing units cost more to make, test and calibrate. It’s really that simple. Vector costs far more R&D wise than Precision. It costs more to make than Precision. They have far different margins than precision does due to company overhead. None of that changes.

      Stages also costs more than Precision to make. They have the crank arm to deal with from a cost/equipment standpoint (the pods themselves are roughly a wash). They have more people onhand to bake and test/calibrate the units. And again, their R&D cycle was longer. Can Stages drop the price? Absolutely.

      You should really go back and read exactly what I wrote. It was applied to those units in the market then, using the techniques they were looking at then for products produced then.

      I’m not really sure what you’re talking about with respect to not wanting to piss them off. I was also clear that from a pure business sense it doesn’t make any sense for any of these players to drop prices until other offerings are actually in the market. Why would Stages drop the price today when for all we know 4iiii’s could hose things up between now and retail delivery? It makes complete business sense for all these companies to milk whatever they can price-wise. I didn’t say that’s create for the consumer, but from a business standpoint (and after all, these are businesses), it makes perfect sense.

  27. Richard

    4iiii really seem to be an awesome company with exceptional product support too. I cant give them enough kudos for just recently replacing a Viiiiva for me due a battery that decided it wanted to turn itself inside out :)

    Currently I have a stages power meter but would be willing to get a pair of these in a heart beat (no pun intended) and sell my stages due to the left leg only limitation.

  28. Bill V

    I’m very curious to see what Power Tap will do to stay relavant with all of the new competition. This seems like a big step forward in price point and hopefully the quality will be up to par as well. All indications so far seem to point to yes.

    • Mr Nofish

      It seems to me with PowerTap being one of the ‘inexpensive’ DFPMs that’s been available for a long time, they should be better positioned than others to drop their prices.

      Yes crank-based PMs are easier to move across bikes and there’s balance (which has no practical use right now and is just another bullet point), so basically they have to pick a good price point so it flies off the shelves and still makes good money.

  29. Happy Runner

    You people are really missing the takeaway from this post. We learned last week that Ray flies coach and in this post he is at a Fairfield Inn. The image of a globe trotting man about town is fading fast. Say it ain’t so, Ray!

  30. John Q.

    I don’t know what to think about this situation. Stages made SUCH a big deal about how their unit had to be installed by them or it wouldn’t work right and/or could fall off. Now we can buy this unit for half the price and stick it on for a couple of dollars with some epoxy and a clamp? Did Stages hose us? Are the people at 4iii’s just a million times smarter? What gives?

    • Technology moves forward. Lessons are learned, and techniques change. That said, do keep in mind that the proof in the pudding is that after 2-3 months there aren’t issues with a large install base of normal users using Precision.

  31. This is great, thanks for the post Ray! Must one actually remove the cranks for installation, or could it be done on-bike?

    • It would be difficult on the left arm but not impossible to install. We are recommending removal as it will reduce the potential for mistakes and getting grease / dirt in the intended adhesion area. The drive side would most definitely need to be removed.

    • Thanks for the clarification Keith!

    • Laurence

      And just as bad as grease on the adhesion area would be epoxy on other parts of your bike. With the right tools removing and re-installing is a breeze.

  32. David R

    I appreciate your confidence in your readers, but it’s been a couple of decades since I saw a sub 20 minute 5KM. :(

  33. Derick

    I was so excited about the price until I saw that its pretty much a permanent application… Now its *plus the price of cranks* because I’m sure as hell not putting it on my current cranks. Not a huge deal I guess since I obviously need new cranks.

    On the other hand, if you have nice cranks this is a great option. Two sided power for the price of one!

    • chukko

      Even with cranks it is still priced competitively, right? And i’d assume that is still only a minority of the people.
      Nearest competitor – Stages – you have to buy crank from them (and only a selected list of those), so 4iiii option looks better to me.
      Sure, this isnt a product which would be migrated to multiple cranks, but is this frequent?
      Actually – if you destroy your crank – i can imagine there would be a way how to remove the crank without damaging the sensor.

    • Duane Gran

      I like Stages a lot, but one of my gripes about their offering is that I would have a leftover crank arm and nothing to do with it.

    • chukko

      Actually on some of the models (e.g. SRAM X9) they offer the option to buy the whole crankset from them.
      It would much more practical if they were able to sell the whole crankset for all the supported models (higher volume could increase their margin).

    • Make another powermeter for another bike!

  34. Thor R

    I eagerly await your full review on this (and then the availability in the Southern Hemisphere). Keith and 4iiiis teaming together has my expectations way up at level awesome.

  35. Mayhem

    Given their history I would’ve expected them to give it a more ridiculous name like Preciiiisiiiion. Product looks quite nice though, assuming they can get it working reliably across the multitude of cranks available out there…

    • chukko

      I also vote for the rename. Ability to use single word in google search and hitting your product only should be a huge benefit, while searching for precision will be more awkward (especially if some of the competitors start to tout how precise their system is :)

    • It’s funny, they asked about that ahead of launch. I think that from a brand recognition standpoint, as well as a Google Search standpoint, the use of iiii’s in product names really hurts them. People can’t spell it, so they slaughter it, which hurts the number of global mentions.

    • chukko

      I agree 4 i’s is too much – you cant quickly tell how many i’s there is.
      But personally i would prefer keeping at least two to have this unique branding.
      Also – google could be addressed by SEO tuning (putting misspelled versions in the headers)

  36. Pete N

    These look to be at a great offering at this price point. Unfortunately for me, from what you say mounting them on rotor cranks looks to be a no go, is this correct, and is there is no way around this?

    It will be very interesting to see what Brim Brothers say today at Interbike. Supposedly we will see details of price, and specification.

    • Rotor flow’s left arm should work, but their normal 3D and 3D+ will not. We understand that this is not ideal for people with Rotor cranks as we are endeavouring to have people avoid purchasing new cranks. Rotor makes some really amazing products and have had great adoption. We knew this design wouldn’t support everything sadly, but it was the compromise for the design.

    • Action Jackson

      Why won’t this work with Rotor 3D / F / + cranks ?
      Seems to be three points of contact for the adhesive to bond with the base of the meter.

    • The grooves on the back mean that there are gaps between the plate which contains the strain gages and the actual arm. This has implications on sensing the deformation of the crank arm. and we can ensure that strain is transferred properly. We have multiple arrangements on the plate. If one of them doesn’t function correctly it can cause the pedal offset error that I’ve talked about. We understand that the Rotor 3D is very popular. In the longer term we will look for a solution, but in the short term we are looking at Flow support for rotor products.

    • Action Jackson

      Thank you for letting me know Keith.

      I kinda wish i didn’t have this new rotor set to install, maybe i can get a sram force crankset going in the future.

      High five on bringing this product out !!!!

    • Ingo

      Has any new work been look at for rotor cranks?

  37. Alister

    Wondering whether, with the accelerometer data, whether a picture of force against angle (like the data that Pioneer produces) would be able to be generated by the Precision kit?

    Irrespective of that, if this gets released on time, I shall be buying myself a ripping Christmas present!

  38. Jorge

    Ok, that’s it then…

    Please make this work on carbon cranks.
    Pretty please.

  39. Barry Gaunt

    What’s with the guarantee? If the pod is destroyed on removal, does the crank & installed pod have to be sent back for inspection?

    • The pod is intended to be installed permanently. Removal of the pod will likely damage the pod and not be reusable. Again, this is a compromise to ensure that the device is affixed properly and it’s calibration is 100% stable.

  40. Gunnar

    I like this. I’ve had a few Viiii products and like their customer service and innovations.

    After using Stages for a bit, I decided to sell it after many issues with water getting into the battery compartment as well as only being left leg.

    I know I have a pretty good discrepancy between left and right leg power (I know this from using Spinscan on my Computrainer) so Stages wasn’t for me.

    This looks like a affordable way to get Left/Right analysis and using Shimano Ultegra cranks, it’s pretty easy to switch cranks between bikes (road and CX).

  41. Fabio

    Just a quick question. I’ve read before that accelerometers and mountain bikes doesn’t mix well together (at least cadence wise) due to bumps. They said they’ve been testing with success with the MTB cranks. Does the accelerometer thing with MTB has been fixed or I still have to use the magnet based sensors? Or am I missing something?
    Great thing to know I’m probably going to be able to afford a power meter next year! :)

    • We are still developing the algorithm further. We are still conducting off road testing and gathering more and more data. We understand the difficulty and it certainly a challenge. Our over the air firmware updates will allow us to continually improve the rotational algorithm and we look forward to supporting and feedback from the mountain biking community.

  42. Søren Haack

    Hi Ray,

    Great news! Finally power meters will be available for all. Do you know that the Polar V800 will support 3rd part power meters like this and not only their own Polar Keo? Based on your Polar visit report it looks like they will but it is difficult to retrieve any official information about the Polar V800 power meter support.

    Mark@4iiii do you know when you will be able to test your power meter on the V800?

    Best Søren

    • We don’t have a V800 in-house just yet, so I can’t give a positive answer to that.

    • ThomasR

      4iiii is the only sensor manufacturer that Polar says follow the BLE standard to a 100%. That is a very promising start at least. Please make these readily available in Europe also. It wasn’t easy to find the Viiiiva, but I did and I’m glad I got one. I’d buy a powermeter from you to go with my Polar V800 anytime. Sending power data concurrently using Ant+ (to TrainerRoad, using an Ant+ stick) and BLE (to the V800) would be wonderful. That’s how I use my Viiiiva.

    • Love to hear this. This is great feedback. We are going to be strictly adhering to the full requirements and will ensure the v800 works before we ship.

  43. David Manley

    And now that’s Brim Brothers have priced themselves too far above this, suddenly I have a new “most likely to buy”.

    I could buy two of these for less than the cost of the Zone option.

  44. Shewey

    > I could buy two of these for less than the cost of the Zone option.

    True, Zone is more expensive at $999 USD.
    However, you can use Zone on any bike, as long as you bring your Speedplay pedals along. Spin class, anyone?

  45. Eppen

    What is the number on the tube of epoxy? It looks to be a Loctite product…?

  46. Sadolin

    Super news.

    Happy to see that Keith is involved.
    I am hoping to see some updates on testing on Campy carbon cranks.
    Where will 4iiii post updates on this?

    A happy Viiiiva user.

  47. Kevin Sundberg

    How about 3m tape vs epoxy?

    3M 4991 VHB

    This stuff holds my gopro camera on my head at 100mph while snowmobiling and can withstand taking hits from tree branches etc. I have no problem with Epoxy except the fact that you basically destroy the device if you want to take it off.


  48. Havelaar

    Additional competition is always good news for us consumers. Fingers crossed that working products will be shipped this winter.

    By the way, any news on the release of the Viiiiva Pods, especially the Viiiiva Mini Heart Rate Monitor?

  49. Harrison

    Exciting times for sure! I’m almost tempted to throw down the $750 for the whole set right now. I do want to see more in-depth testing before I spend my money, but right now, this is my ideal selection for measuring power. I look forward to more testing and reviews in the future.

    The only downside I can think of is crank set selection for myself. I want to be 100% sure I’ll keep the crank set I choose to turn into a power meter. In other words, I need to make up my mind on keeping my FSA K-Light, or switching to a 6800/9000 or Hollowgram. At which point, it might make more sense to purchase a crank mounted power meter.

  50. Mike

    I’d been hoping a more affordable power meter option would come out and one that wouldn’t require much change to my current bike setup. Am I correct in assuming this won’t work with Vision Trimax cranks due to the indention on the back? I’m not at home to look at them at the moment, but the only way I could think they’d work is if the pod actually fit within the indention, though it probably is curved. Looks like I’ll be waiting for your full review on the Brimm Bros power meter or further price drops of other options.

  51. rhys

    I had hopes for this but still, can’t be used on sram omniums because of their shape :(

  52. Jose

    Hi Ray, great review, two questions:
    1.- Besides power, does it messure anything else, like cadence or speed?
    2.- If I have a speed/cadence sensor that goes attached to the left arm (like the powertap sensor) should I have to remove it to properly install this power unit?


    • It measures cadence (+ the various power meter metrics noted above). You can see the cadence plot in one of the graphs I included Speed can’t be picked up from that location though since it has no awareness of forward movement.

      There’s no need to remove other sensors, they can stay on if you’d like.

    • Tom A.

      Speaking of cadence, does the algorithm assume constant rotational velocity within the pedal stroke? i.e. “once per revolution” cadence sensing off of the gravity vector?

    • Tom A.

      Of course, the reason I ask is the implications for their use with non-round rings and “artificial inflation” of power.

  53. Robin

    Sadly, it appears the backside of my Campy CF cranks are are a bit convex, so even if Precision will work with CF cranks, I’m SOL. Damn, this looked so promising.

  54. Ash

    This product looks very interesting, my concern would be warranty. If it does fail during warranty, it is permanently attached to my crank so not sure how returns would work.

    • If it fails during warranty we will be doing a couple of things. You’d bring it to shop who has been trained in removal and clean up. They will do a re-installation of a new pod and re-calibration for you. This is more involved that first time installation as we have some techniques to more carefully clean up and remove the epoxy from the crank. Again, pods are not designed for removal — only one time installation.

  55. Havelaar

    What if I put a sticker on the crank arm and glue the Precision on the sticker (like Brim Brothers seem to do with their Zone on the sole of the shoe)? Making the whole thing removable without destroying it would make it perfect.

  56. Richard Brock

    Does this also display 360 degrees pedal stroke info?

    • Not at this time, though, nobody else except Pioneer does that today (with Vector doing a variant of that shortly).

      I’m hoping we’ll see some progress towards a standard way of doing/displaying that at the ANT+ Symposium Power Meter Working Group meeting coming up in two weeks.

  57. Mike Hobbs

    “4iiii Innovations Enters The Power Meter Race With A Breakaway Design”
    Hmmm, maybe not the best tag line!
    Looks good though, keen to follow it’s progress and UK pricing.

  58. Francis

    Please do one that will work on SRAM S2200 which is SRAM XO crank arm. Will definitely like to have this on my mountain bike, surely a challenge to have carbon arms and on mountain bike, but be willing to test it and pay for it, I’m in Eastern Canada still a few month to ride until snow fall.

    • These are similar to the S900 / last gen SRAM force that we started carbon testing with. These will likely be the first to be supported. We suspect the S2200 / X0 will be similar.

      I’m from the most easternly of Canada (Newfoundland) but don’t forget those trainer kilometers! Winter is base training season!

  59. wim devos

    Hi ray,
    are you thinking about testing the Ibike from newton? I saw it at Eurobike and it seemed pretty sweet to me for several reasons…


    • At the moment there are so many other products at the market that are really innovating quite a bit that it’s hard for me to pull away to spend time on iBike when they haven’t really done a lot in terms of major new features or improved their head unit (for so many years). Also, given the massive drop in direct force power meters, I’m not really seeing the price appeal of the iBike at this point.

  60. Sebastien Gagne

    Too bad my Campy Athena aluminum cranks are curved at the back :( The price is really temping.

    Could they be attached to the outside of the crank ? I don’t suppose so since clearance is probably too tight between the shoe and crank.

    • Technically you can attach to the outside of the cranks (it’s something we actually talked a bit about). There’s no readability issues there, it’s just more of a ‘is that the best location for a pod protection wise’ type of thing.

  61. Mike

    If it turns out this will work on carbon cranks, does anyone know if Vision’s Trimax Carbon would be flat enough to mount this on? I current have the alloy cranks which have an indention on the back, but realized you can get the carbon cranks pretty cheap these days. From the pictures they don’t have the indention, but I’m not sure if the’re still some curve to them.

  62. Austin

    Wondering if these will be compatible with Hollowgram Si cranks. Looking to upgrade bikes and it comes with hollowgrams and would want to keep them. From pictures Hollowgrams look smooth enough. Confirmation would be awesome!

    Thanks for the great reviews!

    • We’ve looked at but not confirmed Cannondale Hollowgram but it does fit the criteria. It appears flat enough and if the pod clears it should be okay. We are working on official confirmation. Please be aware that we can’t measure every single bike frame crank combination for clearance, but there is some adjustability in the location along the arm.

    • Matt

      Do you have official confirmation that the product is compatible with Cannondale Hollowgram yet? Don’t see it on 4iiii website.

      Also, what are the advantages of having left AND right vs. just one side?

  63. Jim

    Maybe it is addressed somewhere, and I just missed it, but I have a fairly simple question.
    Why does the unit need to be fastened to the arm permanently? Why can’t something like cable ties be used? Once it is “locked” in place, there really is no need to be glued.(BTW, it doesn’t have to be cable ties, which some folks might not like).
    A idea like this would make it moveable with minimal effort.

    • chukko

      I’d say that to be able to calculate power they need to measure force accurately. If you tighten the sensor with cable ties – you get very inconsistent readings as cable ties are flexible and move around.
      I imagine you could do that – question is – how far off the results will be.

    • Mr Nofish

      The reason is power meters use strain gauges to measure deformation in the crank arms (if you know how much force it takes to deform the crank arm, then you can infer force applied from the deformation you measured; when you know the distance from the center of the axle, you can get torque. Then finally if you know cadence, you have power)

      Strain gauges basically return an electrical value which depends on how much deformation is applied to them. For them to work properly, they must be attached to the underlying material so that they deform in the same way.

    • This is absolutely correct about deformation and needing a good bond. The strain gages deform changing their electrical value. You can’t get that through non-linear adhesion like tapes or zip ties. The deformation has to be transferred from the arm, through the plate, into the strain gage. The plate acts to protect the gage and makes installation more accessible as it’s durable and robust.

  64. PedroCZ

    How about FSA K-Light cranks?

  65. cl

    OK, dumb question, but will this unit work with a left only power from another company. For example if a rider has a Stages on the left, and a Precision on the right crank, will his Garmin read both meters and will the data be usable in Garmin Connect or Strava?

    • Not a dumb question. The answer is generally no. We hve not intended to support such a mode. The primary mode of operation requires higher speed and due to the operations we think this could lead to anomalies with two crank based solutions. However crank arm + spider could do cool things.

    • Mr Nofish

      Short reply – no.

      Long reply – the problem there is I don’t think any head unit supports two different power meters at the same time (Ray surely will correct me if I’m mistaken). Best you could do is use two head units, each paired to one of the PMs.

    • Not a dumb question. The answer is generally no. We hve not intended to support such a mode. The primary mode of operation requires higher speed and due to the operations we think this could lead to anomalies with two crank based solutions. However crank arm + spider could do cool things like give the true left right balance.

    • And, just to confirm Fish’s point, no, there are no head units out there that support multiple power meters at once. I long for that day…

    • chukko

      Imagine it was available – how would you use that?
      Gear comparison of given metric from all alternative sensors?
      Or combine all sensors of metric to more reliable readings?

    • Well, for me personally in dual-power meter head units it would mean I’d only have to deal with a single head unit instead of 4-5 units + WASP + phone.

    • chukko

      Ah – i was afraid you mean that. Because in practice – you are the only person on the planet with such needs (exaggerating, but still).
      SRM should probably do it – they have the finest display capabilities – and there are quite few features that justify double the price of the rest of the market :)

    • Ian Grant

      ‘There’s an app for that…’

      IpWatts, from the same guy as IpBike, looks like it fits the bill – logs data from multiple ANT+ power meters. Though in the kind of way Ray would use it like the WASP, as opposed to something fancier like combining separate left/meters from different manufacturers.

      Also, IpPeloton, which is similar, shows your data and then that from other ANT+ devices nearby too, e.g. your companion’s HRM.
      It sounds like this kind of thing is ANT+ only, wouldn’t work with Bluetooth 4.0’s one-to-one pairing mechanism.

      Why do you need all the head units, Ray – to see the data in-ride? For just post-ride analysis you could ride with only the WASP, no?

    • Mr Nofish

      Being able to look at the various devices surely holds some value (if nothing else, to make videos), but I think he stated the main point is the WASP acts a backup.

      Ray’s starved for time and he gathers a metric tonne of data for each in-depth review, so if he kept losing stuff because one day that unit stopped working then the other day it’s another one, you can imagine how that would delay the reviews.

      (Hopefully Ray won’t mind too much my replying in his stead)

    • Yup, I use all the head units as a backup to the WASP for data collection. The WASP is generally good but sometimes the app itself is a bit finicky. So as NoFish noted, with such limited time, if I have to re-do a key data section (that could be hours long), it really hurts.

    • Mr Nofish

      Looks like I saved you no time and just lost a chance to shut the hell up.

    • True, one of these days I’ll learn…

    • Mr Nofish

      I suppose you’re being ironic but I really don’t understand what you mean. On that off-chance you weren’t, I was simply referring to my inability to convey the correct information, thus requiring your stepping in.

    • Pete

      Ray, you can pair a DFPM with an iBike Newton.

    • Correct, but I believe only one, the last time I looked (meaning, I can’t pair 3-4 PM’s with it).

  66. Ong

    Will this work with the Look Zed 2 crank in terms of “epoxy-ing” on carbon cranks?

    • Look Zed 2 is a crank that we haven’t honestly been aware off. I’m literally looked it up just then. I’ve never seen it in person so if time permitting I’ll take a look and pictures at interbike tomorrow. That being said, the carbon caveat on fatigue testing each type of carbon crank still stands

  67. Any hints for us Campi riders? Especially if this would work with Chorus or Record and estimations if it would also very likely work with the new Campi group sets that are coming out later his year?

  68. Dan

    Any idea if this will work with my track cranks? Miche Primato Advanced… they look flattish to me!

  69. Tom

    I’m also interested in a track application. I returned a Stages meter for a refund because the cadence and power data got flaky above 120 rpm. Useless in track sprinting as cadences are high and the event is short. A few bad data points means the data stream is useless. Have you tested it in track applications: sprints, explosive tts, high rpm? Will there be an opportunity for higher data rates?

    • I’ve just returned to new updated algorithms. Power is torque x rotational velocity. Our accuracy claim is based on the combined. In order to do so we’re pushing our rotational algorithm hard. We’ll be testing at higher rates and ensuring quality on the rotational side. We’ve already sorted the torque sensing side of things, and we’ll be able to feed out over the air updates to improve this as time goes by.

  70. n8udd

    I’m hoping that this is going to be more accessible in the UK that the 4iiii Viiiiva is.

    Trying to buy the 4iiii Viiiiva HRM in the UK is a joke! In the end I just went with a Wahoo Tickr.

  71. sclim

    Hey 4iiii, how about “Preciiiise”?

    Su-Chong Lim

    • chukko

      See message #98 – it was already discussed.
      I’d personally vote for Preciision – 4i’s is too much – if you dont notice company name you cant tell how many i’s are there .. ii is much more readable and less prone to confusion, while still unique.

  72. sclim

    Whether you would prefer two or four “i”s, my point would be that the word “precise” is pronounced with a long “i” rather than with a short “i” (as in “precision”), and therefore the multiple “i”s in the product name would be more congruent with the long “i” sound of the adjective than with the noun. Therefore “Preciise” or “Preciiiise” would be a less awkward name on the whole than “Preciiiision” which was rightfully avoided by company, or even “Preciision”.

    I like “Preciiiise”(or “Preciise” if you insist). It is short and snappy. It conveys the idea of accuracy, conciseness. No nonsense. The name being an adjective, or an attribute, rather than the usual noun is just enough to make you stop and think a little, enough to call attention to itself, but not enough to stumble. Just my take on it, of course.

    • chukko

      I’d agree – if this “long” i was actually long – it is pronounce as in ice – so doesn’t sound very long to me at all ..
      That logic would better match words like seas, seize, sees .. but unfortunately not precise ..
      To me personally – adjective as a product name is rather disturbing :)

    • sclim

      “Long vowel” is a phonetic convention, in this case to distinguish the 2 main pronunciations of written or printed “i” in standard English, that is, the “short i” as in “pin”, and the “long i” as in “pine”. The “long” or “short” refers actually to the vowel quality, i.e the shape of the mouth, position of the tongue,etc., rather than the number of milliseconds of sound duration. Not to get too technical, I hope, but the “long i” is actually 2 separate vowel sounds mashed together, i.e. a diphthong, pronounced “ah” then gliding immediately into “ee”, so the pronoun “I” which is said to use the “long i” pronunciation is pronounced exactly like the noun “eye”. When I see a bunch of “i”s printed together in a row, as in “Sportiiiis” it triggers the “long i” sound in my brain. Maybe it’s just me.

    • chukko

      Well – i wasnt aware of that. I always learn something new every day.
      But I am not a native speaker so my perception might be a bit off. Seems 4iiii have already made a decision on this, so this discussion is futile anyways :)
      But i’d vote for your proposal – i can even imagine using adjective – but having additional word would make it more natural (e.g. Preciise Power).

    • sclim

      Actually you are in the majority — most native English speakers would also be unaware of this technical area. However, as a side note, I would point out that adjectives, while not common, do actually exist among product names. Just pulling out a random manufacturer, Samsung from a Wikipedia article on cellphones, their Galaxy line has had models named Young, Grand and Stellar, and GM the car manufacturer has had names such as Super and Regal. But, as you say, 4iiii seems to have made the decision, and we are wearing out our brain cells for nothing, haha.

  73. Charlie Anderson

    Is there a minimum length for the crank arms? I’m thinking of my 165mm track cranks.

  74. Just a quick heads up/FYI:

    You can now pre-order the 4iiii Precision via Clever Training. In doing so you help support the site, but also save yourself 10% and get free US shipping using coupon code DCR10BTF! They are currently listed as ‘February 2015′, which is because Clever Training tends to be fairly conservative with dates and under-promises and over-delivers. If 4iiii’s is able to meet the Q4 timeline, then 4iiii’s will be getting those early shipments at that time

    The ordering link for the various products is here: link to clevertraining.com

    • Laurence

      Not that conservative considering we’re in September 2014 already ;-)
      Sorry, couldn’t resist, obviously that should read February *2015*

  75. I just received an email from 4iiii about using the product with carbon cranks:

    Our new Precision Power meter will work with carbon cranks. They have basically the same requirements as aluminum cranks in that they need a flat surface to mount the power meter itself.

    The one question we are waiting for our engineers to confirm is how often we plan to recommend that you recalibrate with carbon. With aluminum cranks you will need to calibrate once at install. With carbon you will need to recalibrate about once per year, but because each manufacturers carbon is slightly different the recalibration times might be different as well.

    So that seems to be pretty good news. Once per year seems like a pretty small price to pay, and even that may or may not be needed.

    • Depending on the cranks, layup, build process, layering, etc this may be more or less. We’ll be putting out our recommendations at the conservative side as testing of each crank arm finishes.

    • Dan

      So theoretically, if I was willing to recalibrate the crank like every month, I could put some of these on my carbon sram (XO, Force BB30) cranks now?

  76. Nicholas Fournier

    Slightly off topic, but did you by chance get to check out the Viva Mini? It’s up for pre-order on their site for shipping in Q4.

  77. JulesB

    Keith – have your engineers tested on SRAM carbon cranks (e.g. Red 22)?

    • Not yet. The new 22 places a bolt on the drive side as they’ve rotated the 5 bolt pattern to hide the 5th bolt. We are still exploring a solution for this type of design.

  78. Laurence

    I was excited when the Powerbeat was announced but it looks like 4iiii beat them to it. I can’t wait for Ray to put this through its paces in a production version but if that’s ok I’m on board.

  79. Any predictions if this might work in any ways with the new Campagnolo group sets that are about to be released or do I really need to invest much more in a Rotor or Rotor/P2M system?

  80. Ruis

    For a right-hand-side unit would it be compatible with various chainring sizes? ie would the smaller chainring of a compact chainrings crank be too small for the unit placement?

  81. scott

    I really like 4iii stuff, and have been looking hard at all power meters wanting not to break the bank on this. Waiting for new stuff like this and other lower cost single sided PM. But when push came to shove, the power tap with shimano wheels went on sale for 620. so this is a powertap WITH wheels vs. $350-400 for the single arm new low price model. Yes, I am sort of locked to those wheels. But proven technology at that price kicked it over the edge, at least for me.

  82. Colin V.

    Boom, preordered last night. Going to install on a Dura Ace 9000 52/36 crankset.

    Had Stages and had to have it warrantied once and then did an FTP test and realized I had a 45/55% power split causing all my power numbers to be 10% lower than they were with my Quarq, effectively making my prior 4 years of power data null in my eyes. Then got a Sworks/Quarq set up and the cranks stick out so far since they are “rounded” my heels hit it and it is causing knee and hip issues.

    Was looking at a Pioneer but this will be less overall and I like supporting companies like 4iiii.

  83. Alec Eror

    Have you tested the Sworks carbon crank?

    • We have an older style in house but it’s inner side is aggressively curved. We are working on getting a newer one with the flatter surface in house.

    • Dan Morley

      I have 2008 SWorks Carbon crank that is quite curved on the inside :(
      Looks like I am back to square 1 as far as an inexpensive power meter goes.

  84. chris g


    How about a usb rechargeable one for the campy users that get bonded to the inside of the crank axle? Narrow and deeper that the Precision.


    • Chris,

      Internally we’ve debated the coin cell versus rechargeable and it was brought up again very recently. There are major trade off’s in the design for each type of battery. Mainly it’s waterproofing of a coin cell (and difficult drive side access) versus electrical and mechanical design issues of the rechargeable, the design and waterproofing of the connector, and finally reduced run times.

  85. I would appreciate if you would sell dummies with adhesive tape or provide data for 3D printing it to test out the clearance under driving conditions.

    • I brought this up in the Engineering meeting today and Mr. CEO says yes, we can post up an STL once we’ve finalized all the testing on the final design. Good idea, and accepted. Thanks

  86. chris g

    Great idea crazyeddie :)

    Keith, I just suggest usb recharging as, I don’t think you can get a a coin cell in the center of the axle : ). I guess you could use something like a triple A or RCR123A

    Keith, thanks for following up and good luck on Precision : )


  87. Xander

    I am very curious about the extended review. Currently using the Viiii heartrate strap and I am really excited about this product. A great powermeter from Viiii would make me an even bigger fan!

  88. Fran

    I was about to order a stages, but I think I can wait a bit and see how this develops. I still share Ray’s concerns about meeting deadlines, especially after seeing the pods announced for April 2014 release at CES (viva mini & sidekick, where is the buzz pod?) still haven’t been released. Anyway, if they deliver on time, and Ray’s review looks good, count me in!

    • Hi Fran,

      Internally we share the same disappointment you have about the pods. There were serious engineering challenges that has necessitated the delay. It’s been a question of do we deliver something that sort of works as we’ve seen in the PPG industry or do we deliver something that works well. Conversely, the powermeter project is based on a lot of proven technologies such as strain gages and as a result has been subject to a much more predictable development timeline.

    • Fran

      Hi Keith,

      Thanks for your reply. I see your point, and really hope to see all issues sorted out on time.
      Will love to start my base block for the next season with Precision ;-)

    • Zach Wilson


  89. Colin V

    So this has been addressed but not for US market I don’t think. If there is a warranty issue with the pod they are supposed to be taken to an authorized reseller for pod removal, crank prep and then reinstallation.

    In the US market how does that work? I don’t see any way to “find a local reseller” in the 4iiii website. Just trying to make sure I understand as if I need to ship the crank to 4iiii i’ll obviously be out of a road bike until I get it back.


  90. Bryan

    Your coupon code doesn’t work.

  91. Mostro

    First o fall, I’m excited to see the power meter market get a good shake-up! Additionally, I’m proud that it’s a canuck company.
    I’ve tried to contact you (4iiii) via your sales email, but have not heard back. I live literally 25mins from your headquarters. Would it be possible to buy the power meter(s) direct and have it installed at your office?
    Thanks in advance.

  92. Hi Mostro,

    Sorry, my fault. While you could buy and pick up your unit directly from us, we’re not able to install the power meter on your bike. It will be simple enough to do on your own though, and we will have local shops in Calgary that will be able to do it as well.

  93. L. Dekker

    Hi there,

    Great power meter option at this price point! I want one!

    I have SRAM XX1 carbon cranks. The surface is flat from pedal to the middle of the crank arm. At the end it has a bend. There is an area with a flat surface and in this area i have more than 9 mm frame clearance. As it is possible using carbon cranks. Is the position where you place the sensor on the crank an issue? I think i can place the sensor right in the middle of the crank arm. Is this possible?

    • The XX1 is very similar to the S900 series. The S900 will be the first one we complete fatigue testing on and likely move to the MTB version (XX1, X01, X0).

      Yes, these cranks are indeed flat enough (very flat in most areas). We’re still finalizing the reduced size of the production pod. It will be shorter than the engineering sample, so you have lots of clearance if you could fit the engineering sample.

      The positioning isn’t a problem. The calibration process takes care of a lot of that, however, the closer to the axle gives us a cleaner electrical signal as there is more deformation. We are still coming up with minimum and maximum location placement.

  94. Zach Wilson

    A couple things, are these really going to be coming out in Q4?

    After these are installed to a particular crank can they be removed and placed on a new or different crank?

    • Hi Zach,

      Yes, our goal is to ship pre-orders direct in December. We have been operating on an aggressive timeline on this product and have been consistently meeting those goals.

      They are not designed to be removed and remain functional. We’ve made certain engineering decisions for that. They can indeed be removed via prying, but the device will likely be destroyed, and even if it is not, the permanent damage would make re-installation improbable and unpredictable. “Re-installed” pods will not be warranted or supported. However, if installation with a new device goes wrong, we’re going to be there to support the user. We’ll have the user bring or ship the crank to a qualified shop who will do a clean up, re-install, and calibration.

  95. Jim

    I haven’t seen this mentioned yet but I feel it merits being known since I know people from the company are monitoring this blog.
    I was an early adapter of the the iBike and I still use it along with using Power Taps units.
    I can assure you that once the temperature drops below about 45*, the life of 2032 batteries is VERY short. They will not perform as you hope.
    My suggestion would be to start looking at alternate or auxiliary ways to provide power in colder conditions.

    • That’s not exactly true (actually, it’s not true at all). In fact, virtually every other sensor and many other power meters on the market uses CR2032, be it ANT+ or Bluetooth Smart. I’ve never actually heard of anyone showing proof that cold temps led to substantially shorter battery life for these sensors. Nor have I see that myself, and I have quite a few sensors.

      If you look at temperature charts for CR2032’s, you’ll notice only a slight discharge change for sub-zero temperatures: link to adafruit.com (that’s just one company that I could find quickly).

    • Jim

      Well, I disagree with you but time will tell.
      BTW, don’t just make a statement that it isn’t “true at all”.
      My experience says otherwise.
      I hope you are right and I am wrong but we will find out in a few months.

    • Eli

      It is a small voltage drop but that can be enough of a drop that its below the voltage the electronics need to work with no error and as the electronics are in a continuous operating mode an error could get the device to enter an error state and not just a one time bad data error. Addidas admits cold decreases battery life: link to community-micoach.adidas.com
      battery will last for about five months (with five one-hour workouts per week) at normal temperatures (approximately 20 degrees Celsius). Extreme cold can decrease battery life.

      And suunto:
      link to ns.suunto.com
      If you switch on the Foot POD in room
      temperature and take it out to the cold, battery consumption will increase. If the
      battery is already low, this may result in it emptying quickly.

    • Eli

      Although in response to Jim, all batteries have this issue and the 2032 being lithium means its as good at the cold as any normal consumer battery, so no real work around.

    • Mr Nofish

      There is no question low temperatures decrease battery life in a general sense, as this (almost?) invariably increases the battieries’ internal resistance (well it might be different if you got batteries made of materials which are superconductors at ambient temperatures but I digress)

      The whole point there is how much. Mr Jim here is saying the effect is catastrophical, Mr Maker’s rebuke is it’s not such a big deal. My personal experience with coin lithium cells suggests Mr Maker is correct, no need to consult spec sheets or look at experimental data.

      Different chemistries may behave differently (if you use NiMH powered lights in the winter you’ll know what I mean)

  96. sclim

    Jim: Your experience is different. In cold weather you have found that iBike+PowerTaps combo had short battery life. You ascribe this to poor battery output of CR2032. However the website that Ray pointed to (which turns out to be the Maxell battery data on their CR2032) shows minimal shift of discharge curves in sub zero temperatures. Could it be that your experience is valid, but the explanation lies somewhere else than poor CR2032 battery discharge at the lower temperatures= ranges we are talking about?

  97. Danny Leopold

    Just preordered mine. Will be using it on my cross bike. Hopefully will get it before cross season is done!

  98. Søren Haack

    Hi Ray,

    Will you test the 4iiii powermeter together with the Polar V800 now that the software has been updated to support powermeters and 3rd part devices? I’m considering the 4iiii precesion if it works with my V800.

    Thanks for your great reviews and for following up on your reviews


    • At the moment I don’t have a current Precision unit on my bike to test with. Given that the Precision is still months away, doing such a test now wouldn’t necessarily tell you much anyway unfortunately. As I’ve seen with both Polar and Suunto, firmware of both the sensor and the watch changes frequently during beta cycles, and when it does things can break.

      That said, I’m sure it will work, if for no other reason than neither company will want to be on my receiving end of things if it doesn’t…

  99. Lars

    Does the crank arm have to be off the bike for the calibration? Or can you calibrate while the crankset is on the bike?

  100. RalfM

    Hi Keith,

    Will the Precision also be available in Europe / Germany?
    Same shipping dates planned as for the US market?
    How will it be offered, online only or also by local dealers?



  101. Tom

    what i would be interested in – and found not too much about – is how the powermeters work in more bumpy mountainbike use. are there differences between the rotor-based (like srm, quarq) and crank-based (like stages and 4iiii) – and do the second work well when only used on one single side mounted?


  102. bikeguy0

    So anyone else cancel their preorder? They are charging your credit card in full to “hold your place in line”. I was leery of that given it won’t ship for 2 1/2 months and they didn’t even have a final design at Interbike of the form factor.

    That make anyone else nervous?

  103. Did you pre-order via 4iiiii’s or Clever Training?
    Pre-order via 4iiii’s directly shouldn’t charge. I’ll double check. I don’t know what Clever Training is doing. If you were charged via 4iiii’s please let us know directly. I’ve alerted the marketing department to investigate this but if you could let us know that’d be great.

    • Update,

      In order to ensure shipping on time due to pre-order demand we’ve changed the setup to accept payment as an order now instead of a pre-order. I apologize for the confusion.

    • bikeguy0

      Thanks Keith. It was through the 4iiii website. I am used to the charge not going through on your card until the product is shipped, i.e. back ordered items. From what I see 4iiii is a stable organization and has more than one product but it makes me nervous having the full amount charged now for a product that hasn’t come out yet. Even with a Stages power meter I wouldn’t be okay with them charging my card in full while I waited for a back ordered item.

      Maybe a more nominal charge like $100 to hold pre order status or something. I would be more willing to do that.

      Thanks for replying here. It really helps the consumer.

  104. Brandan

    I see now that your website is stating an estimated ship date of December 10th. Is this a fairly reasonable projection, or is 4iiii looking at the beginning of 2015?

    • Sorry for my late reply, been super busy. My latest timeline has us still on track to ship pre-orders around this time. Since interbike we’ve been maintaining our schedule pretty well. Pre-orders will be shipped in order they were received, so it’s entirely dependant on volume if people will receive their units before or after Christmas.

  105. John

    Any track cranks confirmed as compatible? DA FC-7710 (looks flat but too narrow)?

    What is the max Watts?

    Thanks, John

    • We have not started looking at track cranks. We have avoided guessing on cranks the engineering staff hasn’t seen. Our primary focus is Aluminum road cranks, followed by mountain bike cranks, followed by fatigue testing of popular Carbon cranks in production. We continue to grow our library of bicycle cranks but as of yet we have not brought in track cranks.

      I believe Mark may have answered your question on Wattage directly, but for others the limitations exist within the protocol and the headunit and not the power meter. In theory you can update 2^16 watts (65.5kw) per rotation, but if you lose a page it’ll mess things up. This is a limitation of the protocol, not the meter.

    • Zach Wilson

      Is there a list of tested and supported cranks somewhere? I’m specifically looking at Carbon road, but if you have a comprehensive list that would be terrific.

    • Right now we’re on a developmental resource split. Getting parts into production is top priority while Carbon testing is lower on the priority spectrum. We will not likely be announcing any carbon cranks until a few weeks after we ship our first production batch of units.

    • Zach Wilson

      Completely understandable. Despite the carbon cranks, can you guys publish a list of all the tested cranks? I know you have mentioned a few here and there, but a list would REALLY help buyers make quick decisions on purchasing. I can tell you that I am in that department. I would love to pre-order, but am apprehensive because I haven’t seen anything that identifies what’s been tested and working.

    • I provided a list to marketing which is more comprehensive. I’m checking on the status of having it published shortly.

    • Zach Wilson

      Awesome. That will be extremely helpful for buyers. I’m certain of it. Thanks so much.

    • John

      Awesome, thanks for letting us in on it.

    • Dion

      Hi Keith

      I’ll be you guinea pig regarding track crank. I have ordered a Precision (only for one crank) for giving it a try.

      If it seems valid, i’ll definitly order for the other crank aswell. I have good idea about my output, since I have been riding with both SRM, Powertap and Power2Max on my track bike.

      So get it shipped and lets give it a go.

    • John Murphy


      What crank is that?

    • Dion

      Hi John

      I forgot to mention that.

      It’s a Shimano Dura Ace 7910 for octalink BB.

    • John Murphy

      Thanks, I look forward to hearing the results.

  106. Sean

    Hi Keith.

    Looking forwards to the 4iiii Power Meter. Can you tell me when it is likely to be available in the UK?


    • I’m not Keith, but I can answer that. We’ll start shipping pre-orders worldwide on December 10th, and we’ll be sending our units out to our dealers and distributors in February of the new year.

    • Mike Smart

      Mark – when you say you’ll be sending units out to ‘dealers and distributors in February’ is that just the date for UK dealers?

      I’ve pre-ordered via Clever Training and was hoping they’d be shipping units at a similar time to pre-orders placed via your own website.

    • To clarify, the Precision power meters planned to ship on December 10th will include both customer and dealer orders, including Clever Training.
      Our goal is to build a strong dealer network and ensure that everyone who orders early will receive Precision in December. We’re still in the process of setting up our distribution in the UK, we expect this to be in place by February.

    • Mike Smart

      Thanks Mark, much appreciated.

    • chukko

      Mark – thanks for additional details. Does the same apply for any EU distribution? So if i want to have the early unit, it is best to order from US?

  107. Davy Van der Linden

    Very interesting product, i want to preorder, but will it fit on SRAM Red?

  108. John

    Is there any performance difference between Ant+ and BLE? Do they broadcast the same metrics?

  109. Alex

    Great article DC and 4IIIIs. Can you tell me what adhesive/epoxy you guys use in the kits? My development Stages power meter fell off, yes fell off despite extra surface prep and a thorough vacuum degassing of the adhesive!

    • They consider that a bit of a trade secret.

      As for Stages, I assume you’ve contacted them to swap it out? And, just to clarify, that was a pre-production unit. For all production units they were done at the factory.

  110. Lennart

    I have some questions about the accuracy since I use a quarq on my other bike.
    From your graph it seems that in some places the power number can vary as much as 50 watt! Is this correct or am i just misreading the graph. That would be quite a lot if i will be basing the training on it, and assuming the power numbers will be the same for both powermeters. Also how much do you think comes from the fact that this measurement is left sided only and perhaps balance might not be 100%. Would be great to see a testride in the final review with this system compared with vector S.

    Another question is about oval chainrings. Because this system uses a accelerometer instead of a magnet does this mean that even puting a ossymetric chainring on the arm it will still be accurate since the cadence can be measured throughout the pedal stroke?

    • Hi Lennart

      Two reasons for this. And yes, we spent a heck of a time investigating this.

      Cadence algorithm. We were using an algorithm that wasn’t fully ready on the accelerometer. I personally made this call instead of using a magnetic sensor. Our initial testing of the algorithm had looked good but we were getting some cadence drop outs. This accounted for part of the average reduction of power. We’ve made great improvements on this. Keep in mind we will continue to improve this like we have with Viiiiva with over the air firmware updates deployable with BLE Android and iPhones.

      We had wanted to show not only with a crank based unit at Interbike, but also with vector and a hub based unit. The other crank spider based units we have and have tested against have all been engineering samples without plastic housings, similar to what had been show, but without it’s plastic housing it doesn’t look finished. We could not let people ride it with an exposed circuit board for many reasons. The only spider based unit we could install and still clear the meter and chainrings with the prototype plastics was the SRM. The spider of the SRM is quite large and as a result, once assembled it pinched the edge of the device causing a desensitization of the drive side.

      These two things combined caused the offset, but even with that it tracked perfectly with other proven meters. Appearing like the calibration value was off — similar to an SRM with the wrong slope.

      Our error calculations so far are based off two combined factors. The error of a torque measurement at any weight and any pedal offset (this has a major impact on many meters out there. Specifically two non spider based units are highly susceptible to reading high / lower based on pedal offset). We calibrate the units with multiple points. Several different points (interpolation, and extrapolation) are tested at various offsets, including reverse mounted pedal offsets. Error = (measured – know)/know. So out known are calibrated weights and our measured value is based on our multiple strain gage setups inside.

      The other side is the cadence algorithm error. Both of these will be accounted for in our claim and we’ll be eventually showing the depth and resilience of our unique multiple strain sensor arrangement and how it stands up. Right now it’s build products and get a final production version in the hands of reviewers and pre-orders.

      Hopefully that clarifies things. I’d suggest waiting to see the reviews from the production units which are much smaller and can more easily be installed with spider based units which will aid in comparison testing.

  111. Jim in Colorado

    Will this work on a SRAM S-1250 crank? for mountain biking? There is a brief reference in a prior comment to additional challenges in power measurement for mountain biking. What is the impact to average power and max power? I have an SRM on both my current road bike and current mountain bike. I’d like to add another mountain bike, but haven’t because I want a power meter on all my bikes and purchasing both a bike and another power meter has been prohibitively expensive. This unit looks very promising if it will be accurate for mountain biking. Thank you for your help!

  112. Ricky

    well i couldnt stay away from the buy button to long, ordered two, one for the TT-bike and one for the racebike.
    Hopefully im gonna have it under the christmas tree :-)

  113. Just hopped on the 4iiii site and saw they had a shipment sold out for december?

    link to 4iiii.com

    This actually make its deadline?

  114. Tim

    For sensor placement, Mark from 4iiii mentioned that “There isn’t any significant impact in moving the pod forward or back, but the closer it is to the bottom bracket the better the sensitivity.”

    For a 2-crankarm installation, do the two sensors (L/R) have to be the same distance from the BB center? Or can they be in completely different relative locations on each arm? What effect would this have on data accuracy?
    I could see each crankarm having different limitations for placement location (chainrings, arm shape, chainstay shape), but I haven’t seen comment on how different locations on each arm would affect L/R accuracy.

  115. Because they are calibrated independently they can be placed at different locations.

    We fully get that the drive side is a difficult place for battery replacement access, as well as frame clearance for the non-drive side. We’ll be making sure we will maintain accuracy that we claim for various different locations.

    We are still working out the guidelines on placement but we have a lot of margin on our electronic side for accuracy. Based on the frames we’ve examined a lot of non-drive sides will likely be placed in the middle of the crank arm, while the drive side near the very limit of where the integrated spider is located (for best battery access).

    So long as you stay in the recommended guidelines we’ll be able to assure the advertised accuracy. It’ll be found in the manual when we ship as well as any online instruction / videos / etc.

  116. Raphaël

    Bonjour Keith,
    Je voulais savoir si vous livrez jusqu’en France et si la livraison serait également prévue pour le 10 décembre ?

    • chukko

      I asked their support – answer was that the first batch delivering in December is completely sold out. EU distributors should be arranged and stocked by February.

  117. Jim in Colorado

    I’m not clear on the issue with using it on mountain bikes mentioned in posts 130 and 131. Is it just an issue regarding cadence? If used on a mountain bike, will the power readings be accurate? Thanks.

  118. Allan

    I have seen the comment at least twice above, but no answer. How do crank arm power meters react to bumpy roads and/or bunny hopping? It seems like the strain meter is not going to know the difference between actual power output and strain due to bunny hopping. And with regards to a bumpy road, how do road vibrations coming up through the frame and the crank arm affect the measurements?


    • chukko

      If i would contemplate – i’d say trying to filter the data in a smart way – when you pedal – the forces are periodic and very different on both pedals and have specific ramp-up/down curves, jumps are non-periodic and rather similar on both pedals.
      I understand it also contains 3 axis g-sensors, that means that can detect jumps and bumps also from that.

    • Mr Nofish

      Do you guys somehow manage to pedal while bunny hopping? if not, then cadence 0 that means every PM that only reports power (not force), should be saying 0 or whereabouts.

      That is because the only thing PMs really measure directly is deformation in the material, whose properties let it calculate the force applied to the pedal, then torque by way of crankarm length and finally power through cadence.

      I don’t think road vibration does anything special to crankarm power meters since, just like any other power meter, they’re attached to your bike and vibrations are already being filtered by your tires (the magical properties of frames and stuff are just marketing fluff, if you’re wondering).

    • Action Jackson

      fluff fluff….that wonderful stuff !!!

    • Allan

      Ok thanks for the intelligent replies. Obvioulsy this stuff is above my pay grade, that’s why I’m asking.

  119. Matt

    I had sent the folks 4iiii an email requesting compatibility on the first gen SRAM Red crankset. Haven’t heard back yet and missed out on the first December order. Crossing my fingers.

  120. Paul Wright

    I want to pre-order one of these but your discount code is not valid? Is that 10% offer finished now?



    • The 10% code is valid on CleverTraining.com, but not on the 4iiii’s site. Are you having issues with it on CleverTraining.com? I just checked the code (DCR10JKW) and adding it upon checkout it seems to work.

  121. Jonathan

    Can’t find any place it’s mentioned.. does is support auto zero? i.e. automatic calibration when you don’t pedal?

    If yes, can it be turned of or is is always enabled?

  122. David Ivory

    Hi, I have Super Record cranks (5 arm not new 4 arm) on Wilier Zero 7 with BB386 BB. Have I enough clearance? Looking at the 4iiii site it appears it should work on my non drive crank, but clearance is only about 10/11mm at best, and only in the middle of the crank. In the review you say it depends where you install it? Can it be anywhere on the crank arm? It’s just the calibration kit looks like it can’t be adjusted. Thanks David.

  123. Lee Sutton

    Any news on when you’ll be getting a production model for an updated review?

    Hope this gets to the UK soon!!

  124. Has anyone had any success installing this device on campy chorus cranks? They have a slight curve on the crank, but the precision site says the 5 arm chorus crank is part compatible. Any real world experience would be welcome.

    • The Precision hasn’t been released yet, so there isn’t any real world experience (well, beyond this post). That said, 4iiii’s has published a crank compatibility chart here (scroll down, click on crank compatibility): link to 4iiii.com

    • Thanks a lot. Yes, based on this table it should work, however the site also says flat cranks only and campy cranks have a slight curve in them. I guess the curve doesn’t impact on where the meter goes perhaps?

  125. Neal

    I am also curious as to whether you will be able to get your hand on a production model. Any word on 4iiii meeting their delivery date? If I ordered from Clevertraining, will they ship out at the same time?

    • I chatted with them on the phone last night. They note they remain on schedule to ship a limited number of units on December 10th as a first production run. My understanding is that Clever Training will get some of that allocation.

  126. David Dagge

    Hi. I’am in the market for a cheap powermeter but with good accuracy. Is this the first one that will come out? When will they start accepting orders agains?

    • We’ll see. Once it releases (be that in December or later), I’ll be able to put it through its paces and go from there. You can still place an order today, but it just won’t ship until next year.

  127. Dan


    Sorry if this has been answered already..

    Has there been any development on the Carbon crank testing?
    I am looking to get one of the pods for my campag chorus cranks ASAP. any clues as to when that would be?

    Cheers buddy

  128. How significant do you expect the changes to be to this device on release? From your concluding thoughts it seems like you are sold on this item if it addresses some of shortcomings and you are confident they can get the niggles resolved based on your history with 4iii. Is that fair to say? I am 90% sold on hitting the buy button as I need a power meter early next year. Would you take the risk? When do you expect to get a v2 to test?

    • I won’t really know until I get a final-ish unit in hand. 4iiii’s is committed to that happening on/about Dec 10th.

      From a risk ordering standpoint, at this point any new orders sound like it won’t be till early next year. So that should give plenty of time to see the results of things with the final production units in December. Cheers.

  129. The code DCR10JKW for clever training does not seem to work.

    • Hi Stuart-

      I just added a 4iiii’s unit to a cart, added the DCR10JKW code, and then the discount showed up (note, it shows up lower on the screen in the order total, not next to each item).

      If that didn’t work – any chance you have a recent Garmin product in the basket? If so, you’d need the VIP program for that (about 7 products right now), but then you’d be good to go for both. Let me know, happy to get you all sorted out.

      Thanks for the support!

  130. Thanks – it doesn’t seem to work for Garmin pedals – it sounds like the VIP issue you mention. Can you assist? The error I get is – Coupon code “DCR10JKW” is not valid. If you feel you have reached this message in error please call us at …….

    • Ahh, gotchya. Yeah, for the Garmin pedals that’s one of the 7 products noted above. You’ll just need to use the VIP program instead: link to dcrainmaker.com

      It only takes a moment though to sign-up and then you’ll get your personal 10% coupon code (that’s good on Vector). Thanks for the support!


    When will then be now…….???…..Soooooooooonnnn…..

  132. ThomasR

    Yeah, a status update (from 4iiii) would be nice, especially since I have paid in advance.

  133. Rui Matias

    When and where can I find sale in Portugal or europe ?

  134. David

    So is this coming out in 10 December? If it does are you planning another review shortly after?

    • I’d have to defer to 4iiii’s on their shipping date plans.

      As for me, once I have a unit, I’ll start my review process. Typically for power meters it’s 4-6 weeks for a full review. But that’s also contingent on a slim travel schedule for me for work. As soon as I have a unit, I’ll be starting that process.

  135. Phill

    Any idea what’s happening with the release? I preordered in October and wanna know when its shipping out. Not that I even own the bike im gonna put it onto yet :)

  136. David

    I know it’s offseason and it’s a period where you ride a lot but i would still like to have soon! Anyone has any information, wasn’t it planned for today?

  137. Marc

    I received and email from them last week requiring me to reply with my crankset model. It was also mentioned that the testing on carbon fiber cranksets have not been completed so they will not be support on this first production run. I had to option of registering for a carbon fiber wait list.

  138. phill

    Bit annoying having to pay upfront then getting no info when the release date has come and gone, tried messaging them on fb, emailing the support and the sales.

  139. Paul wright

    I thought this might happen so I just bought a stages in the Black Friday sales :p

  140. ThomasR

    That’s better. 1st units will ship at end of December. Wonder if the hooks are for rubber bands.
    link to facebook.com

  141. Nick Mannerings

    The Crankset Compatibility chart mentions only one Cannondale crank the “SI Road”. Is this the same as the “Cannondale HollowGram Si” as fitted to the Cannondale Super Six Hi-Mod Dura Ace 2?

  142. Emil

    I noticed that the alloy Campagnolo Athena crankset is listed as compatible for the non drive side.
    Since the inside of the crank arm is concave I wonder how the 4iiii unit would be attached?

    If it works it would be an excellent fit for my Athena kitted steel road bike.

  143. Gil

    How quickly are power and/or cadence changes reflected on a head unit? Quarq reports this information is every 3.1 seconds and Garmin Vectors every 6.1 seconds. This is the lag before the head unit reflects the changes (instant power and/or cadence metrics).

    • Why do you believe there is that much lag?

    • Theo

      Probably from this old thread:
      link to forums.garmin.com
      Under certain circumstances such as sharp changes, or interruptions, in pedaling cadence, Vector can reject a pedal stroke; but the work done is accumulated so you don’t ‘lose’ any of the effort you’ve put in. In the case of the OP on that Garmin forum thread, it’s hard to know how intense the intervals were.
      A second thing is that if the radio link between the head unit and the Vector system is compromised by external interference or by the head unit searching for other sensors (which can happen with the 500, specifically) then you may see periodic delays in information update.

    • Gil

      I timed it with a stop watch. I think there’s probably some lag in the power calculation from the PM, transmission then display. I’m not really sure why there’s such a large variance.

      I’m considering the 4iiii, but curious if you’ve seen a similar lag with it.

  144. David

    Any updates? Should i hit the click the order now on the stages or wait a little more? :b

  145. Roger

    Just tried the DCR10JKW code and seems to be no longer valid….

    • Odd, I just tried it – do remember it’s on CleverTraining.com – and not the 4iiii’s site. Was this on CleverTraining.com that it failed? If so, I’d definitely be happy to troubleshoot.


  146. Nathan Troia

    Has anybody out there received their units form the first order? I keep searching the internet and can’t find any new reviews, etc.

  147. Ahmad Roslan

    Hi DCrainmaker, did u get your hands on the first batch of products? Would like to hear some reviews.


    • Nothing yet. I suspect when I talk with them next week at CES I’ll get a clearer idea of where things are.

    • David

      Do you know if they plan on sending the power meters from Europe? With customs it can get expensive for us on the other side of the ocean.

    • chukko

      I dont think it would have any impact on price. Whoever imports it to the EU needs to pay the VAT – but they need to take care of certificates of conformity too. The only benefit for you, if they sell from Europe, is lower shipping cost and shorter delivery time.

    • Lee Sutton

      The UK distributor will apparently be at the London Bike Show which is mid Feb so hopefully there’ll be some more concrete info on Euro prices by then at the latest!

    • Andy

      Any news from them at CES? The lack of info from 4iiii is a little surprising.

      Still looking forward to receiving my unit.. whenever that might be.

    • Dave

      I’am in a dillema don’t know if i should order a stages now or wait even more for the 4iii…
      4iii is pretty appleaing with it’s price but on the other hand stages has already proved itself i don’t know how long till 4iii starts too ship and if they will be any good…

    • Dave

      Did you talk to them? Sorry to insist but i’am losing my head choosing betwen a stages or 4iii. If the stages was like 150€ cheaper i would have already gone for it.

  148. Dave

    If i order now from Clever Training i will only get in February right?

  149. Graham

    A European distrubitor can reclaim the VAT paid on import. However, he can’t reclaim the 4% duty (UK rate on bicycle parts) nor the shipping costs and he has to add on the VAT to his retail price.
    Bottom line is that in Europe you can’t expect to pay close to the US price as duty, distributor costs and national VAT have to be paid as well as allowing the shop to recover its stocking costs and a small profit.

  150. Dustin

    Any updates?

  151. loren

    Looks like they’re walking back the early representations for carbon, albeit with annual recalibrations.
    Claim they’ll release a carbon-specific version when they have data. Between the lines, possibly the epoxy either doesn’t adhere reliably or doesn’t ensure transfer of stress to sensors.

    I have one on order, if it ever arrives probably would install on my Ultegra equipped road bike…. But had hoped to try it on SRAMplastic TT bike.

    • Nothing to do with epoxy. Purely understanding carbon fatigue on cranks and how it varies over the lifetime of a crank. Understanding fatigue is required for knowing how it reacts to load and thus ultimately your wattage.

    • loren

      thanks for the clarification, ray

      I’m aware of the general argument about carbon fatigue, and was expecting that I’d need to accept some drift for purposes I’d put my TT to, as well as periodic recalibration. However… I guessed a deeper, mechanical problem from four-eyes’ note that installation of first-generation on carbon would void warranty AND that they anticipated a carbon-specific release later….

      Any guess if the carbon-specific release would differ from current models either mechanically or in firmware? Or is the warranty-voided just to keep perfectionists off their backs?

    • On that second piece, they’re mostly holding off on making statements there so to not disappoint people until they know exactly.

  152. simon kidd

    Will we be able to order any at the London Bike show ?

  153. Søren Haack

    Hi Ray,
    I just got the following update on the precession and Polar V800 from 4iiii :” V800 will pick up power from Precision, but we’ve seen problems with it misreporting power. Polar has designed the V800 to work with their Keo pedals, which pair separately. If the V800 sees only one power meter, it appears to assume that it is one Keo, which only reports half of the cyclist’s total power. Precision always reports total power, even when only mounted on one side. Thus, the V800 doubles Precision’s transmitted power, even though it doesn’t need to. The values are consistent, just inaccurate”.

    – So: I would be nice if Polar would make their software so flexible to adjust for power meter on one or both krankarms. Could you address this to your contacts at Polar?


    • Mike

      This ties in with what I’ve seen using a 4iiii Viiiiva to transmit the power from a Powerbeam Pro to my V800. I believe people have had the same issue with other power meters too.

      I’ve reported the problem previously and Polar suggested it was 4iiii not meeting the bluetooth specification :/

  154. Simon

    I wonder what happens if you have a 4iiii on both sides ?
    I suppose you could get the correct reading or 4x the real value ????

  155. Albert

    DC any thoughts on the new method announced today on installation of the unit? I am assuming they were not getting accurate readings on the end user doing the install. Do you still feel its a product worth waiting for or go with Stages?

    • John Murphy

      I’m not DC, but I actually think it’s a better deal now that they’re doing the install , especially for a clumsy oaf like myself. The only drawback I see is the wait time when your bike is sitting at home with no cranks.

    • Zachary Wilson

      They are doing the install? Where did that info come from?

    • Bryan

      I think this product has turned into an absolute joke. What happens when they hit another setback and they have your cranks in hand?? Also, the new ‘design’ is hideous. The initial design w/o the little tabs was far better.

      They might have the sensor figured out, but they royally messed up the rollout. Very sloppy.

    • Zachary Wilson

      I kinda disagree, Bryan. The pictures they have on their site are pretty slick. It’s super minimalistic.

    • Bryan

      To each’s own i guess. I just feel like the original review DC did where they looked like little wedges were more sleek. These look like they added the tabs out of desperation…. Which really, almost everything past the announcement of a pre-order has seemed desperate.

    • It’s really got nothing to do with the installation method. It’s to do with issues shipping the glue/epoxy they were using, from a regulations standpoint. This is effectively a stop-gap they can use to get people on the road quicker than sorting through how to ship the epoxy.

      In the grand scheme of power meter companies, a 3-4 month delay is actually on the low side. Most average 1-2 years.

    • Zachary Wilson

      Yeah, I would say their misstep was probably a premature announcement. That being said, i’m sure they did that to try and build hype and interest in their product.

      DC, so on that note, if you order this the now require you to send your crank to them? How the heck is that going to work for the people that ordered it through Clever Training?

    • You likely simply get a box in the mail from Clever Training to put your crank in. The box will be pre-paid shipping, so then it just goes right to 4iiii’s and back.

      Other companies do the same today, such as Pioneer.

    • loren

      Too bad about not being able to ship the epoxy — so far. I was really looking forward to having that funky “home brew” look and personal involvement to my bike.

      And good news about delay is a chance they’ll have fatigue data on carbon cranks before the season gets going… If not, it goes straight to my road bike.

  156. James

    Is anyone planning on doing the factory install (i.e. mail it back and forth to 4iiii) using an approved carbon crank arm? Clearly they haven’t published fatigue test results for carbon yet.

    Once they calibrate after pod install, what’s the protocol to recalibrate when/if needed?

    Also curious about warranty when factory installed. The website doesn’t seem to go into that.

    These are all the little details that influence the buy now vs. wait it out decision.

  157. I ordered a 4iiii Precision in part on the strength of your review. I even used Clever Training. Thanks for the discount BTW. (I had ordered from them before and they are great).

    I got an email from them today saying that people who’ve ordered a 4iiii power meter from them are going to have to send their cranks in (not sure if it’s to Clever Training or to 4iiii) to have the power meter installed. Anyone who paid $50 for the calibration kit will have that money refunded.

    It doesn’t affect me but the note also said the first generation of Precisions won’t work with carbon cranks. People who have carbon cranks can get a refund.

    Anyone got a loaner set of cranks?

  158. Gunnar

    I just pre-ordered through Clever Training as well (thanks Ray!). With the VIP discount and now the reduced pre-order price, it makes for a very affordable power meter. Not a big deal for me to send in my left crank arm (Shimano Ultegra) as it easily unbolts and I can just grab my other one off my Tri bike to use while I send it in.

    If this works as advertised, I’ll go for dual sided power so I can get right/left power metrics which I really need as I tend to favor my right leg (as I can see on my Computrainer).

  159. Chris

    Ray, what are your thoughts on these compared to Garmin Vector?

    • It’ll honestly depend on how accurate the final versions are. If they’re as accurate as promised, then it will likely make more sense than Vector. Of course, at least initially until carbon cranks are supported, if you have carbon cranks, then Vector will make more sense. And that’s before you get into choices like pedal type, etc…

  160. Adam

    I canceled my order after the recent mail about mailing your cranks in. I don’t think this is a commentary on Clever Training who seems to be trying to do the right thing. My impression is that the product itself just isn’t mature enough

  161. Gil

    Do you have an ETA for the production version?

  162. CerGuru

    The 4iiii seems to be very interesting… especially pricewise. I have two questions:
    – What if I buy a new bike? Can we remove the power meter and reinstall it on another crank?
    – What is the guarantee on the product? Since it just came out, I am afraid there might be some glitch with the intallation and connecting with a Garmin GPS.


  163. John Murphy

    Does this require any manual “zeroing” before each ride like the Garmin Vector does?

  164. Gabe

    so $349 and we ship our pedal to 4iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii ?

    very affordable with the discount.

    Okay Ray – here is another preorder for you – this and the fenix 3 – which ships 1st?! lol

  165. ImRonBurgandy1

    Wondering about calibration- Is this a one time thing, i.e. if you do the current ship to them method, do they do the calibration and you’d no longer need the S type load calibration? On clever training, there is no other option other than “power meter only”, so I’m assuming this is the case? Thanks!

  166. Steve

    The left-only orders getting fulfilled first is really bad form on 4iiii’s part.

    • Jim in Colorado

      I had not heard that — where did you get your info? If true, it does make sense – they can fill twice as many orders and make twice as many customers happy that way.

    • It’s because they’re moving the pod location on the drive side to make it easier to change the battery (otherwise you’d have to remove the chainrings). As part of that, they’re slightly changing the design of the drive side pod. That’s the delay on that side.

    • Kim Bo Jensen

      Hi Ray

      How the new pod battery placement for chain clearance?


  167. Jim in Colorado

    Ray — What’s your expectation on the likelihood of 4iiii being able to solve the carbon crank challenge? I ordered a 4iiii for my TT bike because it has an alloy crank with a flat back side. I plan to purchase a new road bike that has carbon cranks. I would be delighted to order a left/right pair for the new bike so I’m running the same power meter on 2 of my bikes.

    If the 4iiii power meter is going to work on carbon cranks, I would very much like to take advantage of current pricing. What’s your advice — plan on them getting it figured out? or hold off until they do? I realize it is my decision, I’m just looking for guidance since you are close to the action. Thanks!

  168. Nigel Doyle

    Pre ordered on 7 April. Received email 10 April advising my factory install will be May 25 – June 4. I’m very happy with that. I’ve bought a new crankset. My plan is to install on the new set (left hand to start with) and keep the old crankset in case I ever sell my bike. Doing this still brings me in considerably less than buying a Stages PM. I’ll then look at doing the right hand crank later on when the right hand side installs / kits are available.

  169. Andreas


    when will there be an review of the actual revision of the powermeter?
    I can’t wait to order but am uncertain about the parameters like accuracy, reproducibilty, batterie
    lifespan in real life.


    • Yes, there will be a full review. Like most products, I take my time to ensure I’ve got it working correctly. And if I see areas of concern, then I work with the company to understand if it’s a one-off issue, something I’ve done wrong, or something more systematic. This ensures an accurate review that’s representative of the product in whole.

  170. Marcus

    How’s your testing and review on the 4iiii Precision coming along?

    I received mine over a week ago and did 3 rides over the my usual loops. When compared to Stages Power meter, I noticed a discrepancy of around 20%-30% on my average and nominal power differences. Stages read lower when HR, speed and weather conditions are similar.
    I’m aware each power meter is different and does not read alike, 20%-30% is a huge variance.

    I have contacted 4iiii but have not received any responses.

    • Gabe

      Marcus that is unsettling news

      I’m going to go ahead and cancel my order from clever training

    • Mike

      My Precision gives readings very close to my PowerBeam Pro turbo. Difficult to compare with it only being one sided and the location difference but certainly not 20-30% off.

    • Marcus – I’m awaiting a new unit, I saw some issues with the first ones and they’re swapping them out.

  171. ThomasR

    I see indications that not all head units do the calibration properly, problems with Polar V800 and Suunto Ambit. There might be other factors involved and something 4iiii need to test properly, but for now I would recommend doing the calibration/zeroing with a Garmin Edge, if you haven’t already, and see if there is a difference. Please report back.

  172. Marcus

    I calibrate my unit with both the Garmin 510 and the Android app.

    I hope 4iiii will get back to me soon, and I can recalibrate it myself rather than sending it back to the factory (I live in Australia).

  173. Chris

    Received mine recently and it is about 20% higher than virtual power on my Kurt Kinetic. That is all I have to compare it with. I did a steady 20 minute effort with HR the same as my FTP test on trainer.
    Anxious to here Ray’s review. Disconcerting to here he had to send his back because of problem. Would think they spent more time checking and calibrating his before sending to him.

  174. ThomasR

    Virtual power can be all over the place though, depending on tire type, pressure, trainer setup. The same goes for HR if comparing different PMs over different rides, IMHO. I think my values look realistic, but what do I know. I’m not going to buy two other PMs just to verify, am I.

    What kind of problems did you see then, Ray? You seem to indicate that they were bugs, meaning they are fixable with a firmware update.

    • Lee Sutton

      Sounds more like faults than bugs as surely you would just do a firmware OTA update for software issues.

    • I was seeing consistently low power by 10-20%.

      They said they’ve identified the issue and are working to get me a new crank arm. They e-mailed a few hours ago saying they’d get me a status update shortly on where that stood.

    • ThomasR

      I saw that you said “They believe I stumbled into a semi-rare bug on the first units sent to me.” in your Week in Review which had me hope for a software solution at some point. I REALLY wish for a way to now verify if my crank has this semi-rare thing. There is no way I can determine myself whether it’s 10-20% off or not. I’ve seen several people say they get high values, you’re the first one with low ones. You’re the only one that have actually compared values from the same ride though, which is crucial.

    • ThomasR

      4iiii on FB: “We believe that a software fix will address the matters and it is our priority to have that out as soon as possible.”

  175. Gabe

    well i went ahead and canceled my pre-order.

    no way do i want to deal with having to send any unit back for replacement.

    if it’s too good to be true (<$399 power meter) it probably isn't.

    Sorry folks.

    • Lee Sutton

      Same here, hunting around I’d say currently £600 will get either an existing proven reliable unit like original P2M or by the time I’ve got the funds potentially something like PT C1

      Both of those are total power as well and therefore in effect same price if not a touch cheaper than dual sided 4iiii anyway.

  176. Chris

    Not sure what the transmit distance should be but I through bike onto trainer last night the usual 12′ from laptop and TV. Using TrainerRoad power and cadence kept coming on and off while reading steady on my Garmin 800. The GS10 speed/cadence sensor works at this distance. Not sure how far other power meters transmit. Not a deal breaker for me but a minor annoyance.

    • ThomasR

      A USB extension cable is the answer, bring the ANT+ stick closer to the crank. I have mine at 2-3′ and have no dropouts.

  177. Konner

    It’s good to see that they admit that the admit that the battery issue exists, but I’m still not convinced that it is a software issue. Right now even 4iiii are not sure. Could be a design/engineering issue which is more concerning. Personally I’m not keen on purchasing an expensive piece of plastic and then having to send my crank back again for the to replace PM. Right now all we know is that there have been some reviews of the PM, but nothing comprehensive, like those that DCR produces.

  178. Chris

    Ray have you received a non faulty power meter from them yet to test? I would think this would be a priority for them.

    • No. They’re still working through the software bug, so at this point it sounds more likely that sending a 3rd unit won’t solve it. They believe they understand the issue, but don’t have a specific date for resolution.

      Until then, I’ve put the review on hold.

  179. peter

    hay ray have they sent you back a Power meter as they don’t like to give much info about the battery problems and low reading , just hope its a firmware fix ?

    • They’re still working on a fix, which they believe to be firmware. As such, I’m basically on hold. Until then, I’m focusing on other power meter testing.

  180. Albert

    Seems like 4iiii needs to get their act together. First, I really don’t like that they don’t even provide a telephone number on their website. And after I actually found their number from their paperwork and called technical support the response I received was email me. Why so they can let my email sit in their inbox until they want to reply. I don’t think so – from the days of In Living Color – “Hommie don’t play that”

    The power meter we bought for my wife’s bike is having issues. Just the other day it stopped transmitting all information. I replaced the battery and thought all was better (however that’s really fast to have a battery die – 4 weeks). After it synced with the watch and started giving numbers we did a calibration which failed on many attempts. We tried to do a factory reset which also failed. After several attempts to do a factory reset it finally was successful, however noticed that the decimal place for the first calibration numbers was in the wrong place as per the calibration card we received.

    Really sucks that this unit is not very reliable. My wife is training for an Ironman and it would be nice to know that what we paid for actually works consistently.

    Anyone reading and debating to purchase I would hold out for at least a year or longer or just go ahead and buy anything made by Powertap.

    • Gabe

      albert – i went ahead and placed a preorder for the Powertap P1s.

      While much more expensive it’s reliable.

      Good luck getting a refund.


    • David

      I’m with Albert that 4iiii needs to get their act together. I’ve been using the power meter for just over a month now and it seemed to have worked pretty well. Not sure if its reading high or low as I don’t have anything to compare it with but it does run pretty consistent, that is until now. The power and cadence quit reading this past weekend so I figured the battery was dead. (That’s an issue in its self. Battery doesn’t last long.) I replaced the battery, calibrated the unit as usual to my Garmin and the cadence meter started working but no power reading. I had a similar problem with their heart rate monitor and they suggested flipping the battery over for some 30 seconds then flip it back over to the correct position. That worked on the heart rate monitor but it hasn’t worked on the power meter. Did a factory restore still does not work. As mentioned above they don’t have any phone support, only by e-mail. I sent them an e-mail Monday and as of Thursday afternoon I still haven’t received any response from them. When you look at their Friday file on their website they talk a lot about the events they attend but hardly anything about issues their products are having. They seem to want to spend more time playing than on getting their business going. Maybe need to grow up. I wish I had spent the extra money an went with Stages. They don’t seem to have issues with theirs and they diffidently have better customer support both on their website and phone. I would suggest that until 4iiii gets their act together spend the extra money ad go with another power meter instead of the 4iiii precision meter. Not worth the head ache nor trouble of dealing with them.

  181. Allan

    Any further update or observations re: low power readings? I’m starting to see this issue being brought up all over the place. In some respects, it’s not *that* big a deal, as I don’t race, and don’t necessarily need 100% accurate numbers, as long as it’s consistent I can use the numbers to help me improve. But…10, 20, 25% that’s a LOT of error, if true!

  182. JAVIER

    If the problem is to ship the glue, why don’t they use rubbers bands as the new garmin cadence sensor? The pod seem to be very similar. Easy way to install, 0 problems.

    • JAVIER

      And furthermore, you can use one for differents bikes, just changing the pod.

    • Andy

      JAVIER, I think you’re missing the point of how power measurement works. It’s essentially a strain gauge and needs to be very, very solidly adhered to the crank material.

    • JAVIER

      I’m not an expert on the topic, but in the last iteration of the garmin cadence sensor, with the triple rubber band it seems that it’s quite solid. I don’t know if it would be enough, but I throw the idea just in case. It’s a pity that because of the glue “issue”, they are not selling the pod directly.

    • chukko

      That rubber only assures the pod does not fall off – the cadence sensor detects everything via g-sensors.
      On the other side – powermeters work by measuring how the sensor is strained (measuring tension forces). The rubber does not transfer forces to the sensors at all – it is the rubber which is deformed, not the sensor.
      The quality of the bond is the major factor in powermeter reliability. Thats why all other companies do not let you glue that yourself, you buy the whole crank.

  183. Patrick Young

    Ray would you expand on how your pedaling style doesnt work with the 4iiii. They are fairly high on my list but dont want to have to wait for a bug fix.

  184. JB

    I got my dummy kit yesterday to see if the Precision will fit despite the fact I had direct mount BB brakes and it looks like I can. It’ll be glued close to the BB where it clears the caliper.

    I’m set on getting these now (from clevertraining!) but I’m not quite happy they haven’t addressed the pedaling bug on their “friday files”. I’m going to hold on until they fix that.

  185. We have ordered and paid for a version of 4iii Precision in January 2015
    We chose the self-assembly.
    This version was no longer available as of March.
    Until today we were not delivered or if we have not received a refund of the purchase price.

  186. David

    I have been using the Precision power meter since first week of August. The power meter itself works fine and is a bargain at the $350 introductory price. However I am in a couple things. One the battery only lasts for about 3 1/2 weeks, depending on how much use it. I was only using it about 3 times a week. Then when I changed out the battery I finally had to do a factory restore after a considerable amount of time to get it to recalibrate. Another issue is their customer service. They only have e-mail support and seems they get to you when they’re not busy doing other things such as attending races as noted in their Friday files. It took them over three days to respond to my support request after I had committed on their Facebook page for help, by that time I had already figured it out. Seems they’re not quite as committed to their product or customer service as the power meter companies. I think until they get more serious about their business I would go they extra expense and buy a stages or something else. Don’t know anything about the Stages power meter, maybe somebody else could chime in on that. At least Stages has a whole web page knowledge base setup for customer support. 4iiii doesn’t have any such help on their site. Also, I’ve been using their Viiiiva heart rate monitor strap for about 6 months now and it’s not all it’s cracked up to be either. I bought it for it’s blue tooth feature but it has poor battery life and inconsistent reading. Garmin a much better product.

    • Have you upgraded to 0.2.0 on precision? It should give a very significant improvement on battery life.

    • sclim

      Gotta say I also had problems with short battery life in Precision until I refreshed a corrupted firmware and upgraded to the latest versionin late July just before a Half Ironman race. It works great now with good battery life. I also had high battery use problems with the Viiiiva when I used it intermittently with a Bluetooth App. It turns out I wasn’t closing the BT app properly and so the Viiiiva was still searching for the App in Bluetooth when I was using it in purely ANT+mode. I still mostly use the Viiiiva in ANT+ now, but when I use the BT app on the odd occasion I make sure to exit the app properly, and I have no problem now with the coin cell lasting multiple months of heavy use. I bought a MIO link hoping it would replace the Viiiiva, especially in swimming, but so far it only works reliably in cycling. It seems to pick up my arm swing in running and reads it as a heart/pulse beat, so for running I’m still using my old Viiiiva exclusively, and almost all in ANT+, unless I’m on the treadmill, when I also use it in BT on my iPad 4iiii app.

  187. David

    Whatever the latest upgrade was 10 days ago. Reckon their support and customer service needs a battery changing???

  188. Chris

    Ray were you able to speak to 4iiii at either Eurobike or Interbike about the right side pod? I bought in early but don’t want to go into next season with left only power. I have had a bad leg injury and really wanted to see how my recovery has gone. More options out now that I would have gone with. Feel like I only have half a power meter. Should I give up on 4iii or is there still hope.

  189. CHRIS

    That would be great. Thanks

  190. mindanalyzer

    Would this work on Look zed 2 carbon crankset?

  191. ManuB

    Bought in july 2016. Dead in January 2019.

    Battery caps be dead and its impossible to saw that : send to precision : 200 dollars to repair because some water come inside ! (50% discount for the repair….).

    I dont recommand to buy this powermeter, not strong enough : lifetime #2 years.