12mm Thru Axle for Trainer: 172 mm with 1.5 Thread

(23 customer reviews)

$ 54.00

Our Trainer Axle is designed to adapt your thru axle equipped bike with your on wheel trainer, such as a 1up, Blackburn, Cyclops, Kinetic, Tacx, Wahoo and many other trainers. Our goal is to fit the thru axle to your bike perfectly, so we minimize spacers and extra parts, providing a clean, high performance axle for your bike. Train, warm up and be race ready and fit for the season.

SKU: TRA204 Category:


  • This Trainer Axle is designed to adapt your high quality bike to your on-wheel trainer. These are compatible with all the popular brands: 1up, Blackburn, Cyclops, Kinetic, Tacx, Wahoo and more.
  • Our first priority is building a precision thru-axle. Our axles fit into your bike as well or better than the stock thru axle.
  • The axle is installed with a simple 5 mm hex/allen key. The same tool that you carry on every ride.
  • The best part? When it’s time for your race or time to head outside, simply remove your bike from the trainer, remove the drive side axle end and go. Our axle is suitable for use on or off the trainer. Indoors or out.
  • Important: Before you order, make sure your specific trainer will accommodate the width of your modern thru-axle equipped bike. Measure your trainer at the widest setting and measure the outside width of your bike frame. Our the trainer axle ends will extend past your frame on each side.



Robert Axle for Trainers replaces your stock 12 mm thru axle so you can use your bike on a trainer.

  • This axle is compatible with 1up, Blackburn, Cyclops, Kinetic, Tacx, Wahoo and many other on-wheel resistance trainers.
  • The true length of the axle shaft is 172 mm. Please note: Thru-axle lengths do not equal hub standards. An axle has to be longer than the hub to fit in the frame. A 12×142 hub does not equal a 142 mm long axle.
  • This axle has a 1.5 mm thread pitch.
  • The axle shaft and axle ends are precision CNC machined from 7075 aluminum, and hard anodized for rugged durability.
  • No special tools required. Design allows for installation or wheel removal using your standard 5 mm hex wrench.
  • Designed, built and quality tested in the USA. Proven around the world.


Need more information about how our axles work?

23 reviews

  1. Carter

    Great product from these guys. Use mine all the time and also works well as an upgrade from the stock TA on pretty much any bike. Seems to have better tolerances than the DT Swiss one that came with my bike and eliminated the creaking that would occur due to DT’s slack tolerances.

  2. Danno (verified owner)

    I was a little worried at first that I would have to return my trainer. RAP had just what I needed. I printed out the guide and used it to cut out the guess work. I got the right one within days.

  3. Chris Kuhl (verified owner)

    Awesome product, very fast shipping. I was surprised when I couldn’t find a 12x142x1.5 axle for my Marin hard tail 29er so I could use it on my trainer. This jus the solution and works great, the quality is very nice, highly recommended.

  4. J black (verified owner)

    Works as advertised. Shipping was very quick, especially for the time of year the order was placed. Thanks.

  5. Pierre (verified owner)

    Ordered this axle for my Yeti SB4.5c.
    In order to fit the axle, I had to remove the lock nut on the drive side and add a washer.

    With this modification, I was able to use my Yeti on my home trainer

  6. Mike (verified owner)

    Robert Axle Project was recommended to me by the team at Raleigh for my Merit. What a perfect solution! The axle has been a great fit for my CycleOps PowerPro. Easy to install, and works wonderfully with both systems. There was a point where I started to doubt that a solution existed for the wide drop-out on the Merit, but this was perfect.

  7. DocWass (verified owner)

    Exactly what I was looking for! My new bike has 12mm thru-axles and came with a kit to change out the rear to QR drop outs so I could use it on the trainer. I didn’t want to hassle with changing back to 12mm for road riding and the 5mm QR drop outs looked like they would flex. Found these and initially thought they were a bit expensive but the reviews persuaded me to part with the money. The fit/finish is excellent and the bike fits securely in the trainer. The added bonus is I don’t have to change it back for road riding. Perfect!

  8. Shawn Chervak (verified owner)

    I searched on the internet then called Diamondback to confirm length and pitch. They recommended these axles over anyone else, which eliminated any doubt for their axle to work. It’s simple and perfect, works great with my trainer that I have left the axle in when I do head outside. Even with a recent puncture there was no more of an incovience in pulling the axle out to patch the tube.

  9. Logan (verified owner)

    Works great! Almost thought I had to return the trainer I purchased. Chart made it easy to make sure I got the right size!

  10. Chris (verified owner)

    Great Product MADE IN USA! Was bummed when I bought my new Salsa Warbird and couldn’t find a thru axle to fit my trainer. Salsa actually recommended RAP! Great company, in stock products, fast shipping= Happy customer!

  11. Patrick (verified owner)

    great product, only 4 grams more than the stock thru-axle bolt.

  12. Lee Waldman (verified owner)

    These guys are great. They had what I needed when no one else did. I received my product quickly, the price was fair and they are great about responding to questions. I wouldn’t hesitate to deal with them again when the occasion arises

  13. terry (verified owner)

    great product works well with my trainer – perfect fit for the bike ! delivery to New Zealand only took a week ! would definitely shop with again

  14. Joe Janney (verified owner)

    Great product. My wife and I both use our Wahoo Kickr Snap trainer with bikes having different axles. The Robert Axle Project axle allows us to quickly swap out our bikes without making changes to the trainer. My wife’s bike has a standard axle that fits with the rear axle equipment the Kickr Snap provides. My bike has the through axle that would have required me to buy a conversion kit from Wahoo at $80, then swap out the two different axle holders on the trainer when moving between bikes. I saw a note posted on Wahoo’s site about the Robert Axle Project and found this site and purchased the trainer axle that fits directly on the Kickr Snap trainer without the conversion kit. You should contact Wahoo and see if they would sell your product on their site vs. the conversion kit. This is a much better solution. Keep up the good innovative engineering!

  15. khanh (verified owner)

    Quality product, arrived very quickly and by using the print out to get the correct thread pitch, length it fit perfectly for my Pinarello Dogma F8 on the Wahoo Kickr Snap

  16. Brian (verified owner)

    I bought an axel for my 2017 Fuji Jari to pair with a Wahoo Snap Trainer. The installation was easy and it works perfectly with both the bike and the trainer. I’ve put about 200 miles on the axel so far and it works great. No complaints and I’d recommend it in a heartbeat.

  17. Curtis (verified owner)

    Good stuff! Perfect fit, clean look, does exactly what it is supposed to.

  18. Erik S (verified owner)

    Exactly what was needed, this fits on the trainer perfectly plus I can remove one side of it if I want to and just run it as a normal axle that fits flush to the bike. Better than the stock axle!

  19. Thomas (verified owner)

    Perfect fit for my trainer. Fit my bike like a glove too!

  20. Bob Grier (verified owner)

    12mm 172mm w 1.5 thread – Perfect fit (with the one washer that was included without my request) for my Wilier GTR Team Disc and CycleOps Fluid trainer. The Robert Axle Project team handled my pre-sale question quickly and the entire process was seamless. Thanks very much!

  21. Nathan Morgan (verified owner)

    Solid Product and very well made. Would like to see a captive washer rather than a free one so I won’t lose it, but then it might not fit on every frame. Bought the lightning bolt on axles as well. Nice ’80’s reference to boot. What’s not to like?

  22. Derek Morrison (verified owner)

    This is a great alternative to the thru-axle kit for the Wahoo Kickr Snap. I don’t know why Wahoo didn’t use this design, as it’s more functional. I can use the trainer on my bike with this adapter and then fairly seamlessly switch to using my wife’s bike (which has a standard quick release) on the trainer.

  23. Connie Petrick (verified owner)

    Have a Diamondback Airen5 Carbon and Mag Trainer. Bought the 12 mm thru axel; 172mm with 1.5 thread. It fit and worked perfectly. Great product and prompt delivery. Would definitely recommend to others with similar needs.

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All orders from our website are via US Postal Service, from Oregon, U.S.A. We make every effort to ship your order within one business day.

Shipping rates and average delivery times are:

• United States: $7.50 USD, 3-4 business days

• Canada: $12.50 USD, 10-14 business days

• All other International: $12.50 USD, 12-16 business days

We are unable to offer expedited shipping. If you need expedited shipping of our products, please visit our Dealers & Distributors page for options. We cannot take responsibility for any delays during shipping, including delays in customs or incorrect shipping information.

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