A look at the Trek/Bontrager frame integrated DuoTrap ANT+ Speed/Cadence Sensor

A few weeks ago The Girl brought home her new bike, the Trek Speed Concept, which is one of the very few bikes out there that includes the option to add a frame-integrated ANT+ speed/cadence sensor.  The sensor kit fits into the frame itself – becoming quite aerodynamic, as well as simply just ‘out of the way’.  The goal here is having a speed/cadence sensor that just flows with the bike, allowing you to gather speed (thus distance as well) and cadence data – whether indoors or outside.

Now despite this feature being only available on Trek’s higher end bikes (around $2,000+), it doesn’t actually come with the bike.  For that you have to order the separate $59 kit from Trek.  The kit is actually made by Bontrager though, which of course makes a variety of bike-related components as well as a few ANT+ enabled products.

Upon realizing that the bike didn’t come with the kit I went ahead and ordered it – I was probably more eager to play with it myself than The Girl was.  But of course if you read here often, you probably figured as such.  After ordering it on Trek’s site, it came a few days later.  Here’s what it looks like in its package:

Before we get all started – I should probably show you what’s in the bike prior to installing the above kit.  The bike by default comes with a little plastic placeholder kit.  From a distance you might assume this is the real deal, but once you get a bit closer your notice the ‘DuoTrap Ready’ wording – indicating the need to buy the actual kit.

Once I was ready to install the real deal I went ahead and got the package all taken apart next to her bike.

Inside the packaging was the DuoTrap frame sensor, a rubber crank magnet (pretty cool actually), and then a screw and rubber screw cover.  In theory it also comes with a small magnet for the wheel (to gather speed), but mine was missing.  No worries though, any standard wheel magnet will work – so I just used the one on the wheel from another sensor kit.  It’s only a $2 part from a bike store, so I wasn’t about to make a big deal out of trying to get the kit replaced.

And for fun – here’s what the main component looks like up close:

Here’s a general size comparison to the more common GSC-10 speed/cadence sensor:

And finally, here’s a comparison between the real and fake one:

Once I was ready to start I needed to remove the fake plastic DuoTrap.  This involves finding the correct hex bit to fit in the tiny screw:

After that’s done you simply unscrew it.  Fear not – it only takes one triathlete to unscrew it:

From there you’ll notice that you can actually see through the frame.  Like a little window on the world…or rather…the wheel:

This window allows you to slide the speed sensor portion of the kit through the frame, ultimately putting the magnetic sensor portion close to the wheel magnet:

Once you’ve got it slid into the frame, you repeat the same screwdriver process as earlier – this time tightening instead of loosening:

With that, the sensor kit is set.  We just need to add your normal spoke magnet onto the wheel.  In my case that was all already set (no tools required!), so I moved onto getting the cadence magnet on the crank. However unlike every other cadence magnet ever created on earth – this one doesn’t use zip ties.  Nope, it uses a fully integrated rubber band system.  Industrial strength rubber though – not like something that rolls up your newspaper.

The only tradeoff with not using zip ties is that you’ll have to first remove your pedal though, to be able to slide it over and down the crank:

Once you do that, you’ll get your mojo on and push this thing down the crank.  It’s an incredibly tight fit – so you don’t have to worry about it sliding around.  Again, only one triathlete required…though non-triathlete cyclists may need to find a friend that has arm strength.

Once that’s on – reattach your pedals and you’re good to go – kit installed!

The last step you’ll need to do of course is pair up your ANT+ head unit to the speed/cadence sensor.  What’s really cool here is that it uses the standard ANT+ device profile of “Speed/Cadence” – which means EVERY ANT+ cycling focused device out there supports it out of the box (as opposed to some of the newer speed-only and cadence-only ANT+ accessories).  Just a few devices off the top of my head that work without issue are:

Garmin: Edge 500/705/800, Forerunner 305/FR310TX/FR405/FR410/FR60
CycleOps: Joule
Timex: Timex Global Trainer
Bontrager: Node 1/Node 2 Computers
Phone: Wahoo Fitness iPhone ANT+ Dongle, Android Sony Ericsson ANT+ enabled phones, Enki Fitness iPhone ANT+ Dongle, Digifit iPhone ANT+ Dongle/Case
(And many more of course, these are just the most common)

Here’s what it looks like once it’s paired up (using an Edge 800 as an example) – you’ll see the sensor display connected, as well as during normal operation:

Then you simply bike like normal.  The speed/cadence information is transmitted wirelessly via ANT+ to your head unit.

(Normally I’d suggest placing the display near your handlebars, and not the rear cages, but it made for an interesting picture back here.  And more importantly – The Girl was away…so I had to crank, watch and shoot all by my lonesome…on a bike small enough for a circus clown).

You’ll want to configure your wheel size on the head unit – thus allowing accurate distance and speed measurements using simple math calculations.  Also note that the unit uses a standard coin cell battery, which is replaceable just by removing the DuoTrap and unscrewing the battery compartment.

While overall the DuoTrap is indeed more expensive than the more commonplace Garmin GSC-10 sensor (at $30, compared to the DuoTrap at $60) – I feel that if you’ve got yourself such a nice bike, you might as well pay the little bit extra and have it be fully integrated.  Additionally, because there’s no adjustment arms – you don’t have to worry about the occasional never ending re-configuration issues with it moving over time.  It just works.

DC Rainmaker :

View Comments (195)

  • Is the Garmin Edge 25 compatible with the DuoTrap? If not then what inexpensive devise would you recommend that displays distance in one hundredths rather than tenths as in the Node 1 which is hard to see in certain light conditions. Thanks!

  • I have a trek duo trap speed cadence sensor on my Trek Silque. I took the plunge and bought a Garmin edge 820. The cadence reads well but the speed is all over the place. Someone told me to take the magnet off because it was getting readings from the satellite as well as the magnet. Thus I would be riding at a steady cadence and the speed would read 15mph one minute and 12mph and then less. In short it was jumping all over the place. I am not particularly tech savvy but why is this happening. Is it the device or user error? I can't seem to find an answer.

  • Hi just after a bit of help. I've installed the bit into my frame, took my pedal of, slid the band on and reattached my pedal. However the band is too thick and there isn't enough distance between the crank and the frame for the band to fit through so I can't even do one rev. I've had to take it off. Any suggestions on how I can alternatively measure my cadence/speed

  • Mr Rainmaker,

    Love your work. I am trying to pair/sync my Suunto Ambit 2 with the duo trap but, for the life of me, cannot do it. Are you able to give me some instructions as to how to do this please?

    Speed and cadence PODS are ticked on moves count but the watch doesn't search for them (I have found this is the best way to get it to work from the rest of the www)

    Any info would be helpful, thanks

  • This was a 2011 review. Are you still a fan of the trek duo tap and do you know of other manufacturers who now 2017 have frame integrated sensors?

    • To be fair, it's been updated to broadcast Bluetooth and ANT+. (The product name now has an "S" in it.)

      Since it fits into a Trek frame, reliably counts wheel and crank revolutions, doesn't go through batteries quickly, and, well, just works, it isn't clear why it needs an update.

      If you don't own a Trek frame, or are asking what other frames have integrated cadence sensors, ... then you might look at:


  • I'm ready to throw the Bontrager duotrap whilst still attached to bike over into next doors garden!!!! Why won't it work? It did work for a few miles and I was impressed.It stopped and there's no way i can re-connect. I replaced the battery too. I'm connecting to a Garmin Fenix 5, or was. Whats going on???? I've spent the whole day on this and getting nowhere. There must be some explanation in how to start pairing. I've turned bike upside down and spun wheel and crank. To be fair, I've had a right workout just in my arms alone, spinning the crank, but was hoping to work the legs. Before anyone replies, I can answer yes to.....battery out and in, and spin twice. I can answer yes to....disconnect from watch and re-connect. I can answer yes to...try another device. I can answer yes to...another battery. I can answer yes to...... move magnets to other positions. I can answer no to......another duotrap

  • Thank you so much for your outstanding and incredibly helpful posts!!!

    Can the rubber cadence part work on a crank with Watteam power sensors (I want to have both if possible)?

  • I got me a Trek Emonda back in March. (She SCREAMS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!) Do you have to have a compatible Garmin computer to use the duotap, or could you sync it with an Ant+ app on your phone?

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