Paul Cutting

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Review: Trainer Thru-axle by The Robert Axle Project

Review: Trainer Thru-axle by The Robert Axle Project

I spend a lot of time on my Wahoo Kickr Snap smart trainer and it was a real bummer when I discovered that it wasn’t compatible with thru-axle equipped bikes.  I recently purchased a new road bike that came with thru-axles. Really, I didn’t think that making the Kickr Snap thru-axle compatible would be a big deal but I was in for a shock. 

To convert the Kickr Snap to work with a thru-axle system the first place I went was to the Wahoo website to purchase the thru-axle conversion kit from Wahoo.  Bingo, easy to find but when I saw the cost of the kit I almost fell over.  $115 for the kit, are you kidding me?!  Well at least the Wahoo kit came with three thru-axles to address the variety of standards. However, I only needed one thru-axle and I couldn’t justify paying extra for two axles I didn’t need.

There had to be another option.

A quick google search and I discovered a company called “The Robert Axle Project”.  I did some reading and found that this company makes all kinds of axles, including one for trainer use.  Simply replace your existing axle with their trainer thru-axle and your bike would clamp right into the Kickr Snap.  The thru-axle is meant for indoor and outdoor use so no need to swap axles.  An added bonus is that it was much more affordable than the Wahoo conversion kit.

Something I’ve learned after purchasing a bike with thru-axles is that there is a wide variety of axles specifications. I can’t keep them straight and I haven’t been able to remember what my new bike uses.  The Robert Axle Project website made finding the correct sized axle a breeze with their axle finder tool.  I went through the questions and made my purchase. A few days later the product was delivered and I got down to business.

Robert Axle Project thru-axle packaging

Above is what came in the package. Straight forward, no need for fancy packaging.

Let’s get the axles on my ‘highly accurate’ scale to see if there is a weight penalty against using your factory Cervelo thru-axle. 

Weighing a stock Cervelo R3 thru-axle

The stock Cervelo thru-axle weighed in at 72 grams.

Weighing the Robert Axle Project trainer thru-axle

The Robert Axle Project thru-axle came in at 73 grams including the end cap.  The plastic washer may or may not be needed depending on your bike, it must be less than a gram as the scale didn’t report a change when I removed it.

Weighing the end cap of the Robert Axle Project thru-axle

The end cap weighed in at 12 grams.

This means that if you leave the end cap on the Robert Axle Project thru-axle you will come in 1 gram heavier than the stock axle.  In case you need to satisfy your inner ‘weight weenie” remove the end cap before your outdoor rides and you save 11 grams over the stock Cervelo axle. 

The installation instructions are straight forward.  Remove your thru-axle and replace it with the Robert Axle Project thru-axle.  Put a little bit of grease on the threads to keep your bike happy and then tighten it up with a 5mm allen wrench.

Greased threads. Robert Axle Project thru-axle install
Tightening teh thru-axle. 5mm allen wrench
Installed thru-axle from the drive side

As you can see it threads in just right and tightens up as it should.  No drama here.  This is technically ‘outdoor’ mode.

To finish off the installation and make your bike ready for use on the trainer, you now thread the trainer adapter piece into the open end of the thru-axle.  This is the piece that your Kickr Snap needs installed in order to hold your bike in the trainer.  Add a little grease to the threads and tighten it up with a 5mm allen wrench. 

Installation of axle end cap with greased threads
Top down view of installed Robert Axle Project trainer thru-axle

Installation complete.  Now let’s put it into the Kickr Snap to see how that works.

Wahoo Kickr Snap
Kickr Snap clamping Robert Axle Project trainer thru-axle.  Drive Side
Kickr Snap clamping Robert Axle Project trainer thru-axle.  Non-Drive Side

I jumped on and tested it out doing a time trial workout in Zwift.  Riding in the trainer with the Robert Axle installed felt no different than riding in the trainer with my older bike and trainer skewer.  Perfect.  I’ve also been outdoors with the new axle installed and there is no perceivable difference in stiffness from the stock skewer, I even left the end cap for the trainer installed as I’m not that big of a ‘weight wienie’ and it makes for an easy transition to the trainer.

In conclusion this was a great product at less than half of the cost of the Wahoo conversion kit.  A solid product which I can fully recommend.

Make sure you carry a multi-tool with a 5mm allen wrench in your flat kit.  Just in case you need to repair a flat.