12mm Thru Axle for Kid Trailer

12mm Thru Axle for Kid Trailer

(28 customer reviews)

$ 58.00

Robert Axles for Kid Trailers are designed specifically to fit your 12mm thru-axle bike and allow attachment of any hitch-mounted trailer. These fit any trailer that has two wheels and a single point of attachment to the axle. This includes all the two-wheeled child, pet and cargo trailers such as: Thule, Chariot, Burley, Instep, Carry Freedom, and many more.

Purchase our Kid Trailer axle for your bike. Share your stoke for cycling with your kids. Simplify your life by allowing quick and secure attachment of your trailer to your best and favorite bike. Enjoy the adventure.

SKU: KID226 Category:


Since 2013, we have been an important part of cyclists’ adventures all over the world. Our axles have millions of miles on them in mountain bikes and road bikes, carbon bikes, fat bikes and e-bikes. Our axles are specifically designed to handle the high-torque loads generated by e-bikes.

Your stock thru-axle is not strong enough to haul your precious cargo! Our axles are 3 to 4 times stronger than the stock axle that came with your bike. Our stainless steel axle ends provide a safe and secure attachment point of the hitch to the axle. The axle is quick to install and remove with a common 5mm hex key.

Our axles are not just designed in the USA, but are made here as well. They are machined by avid cyclists to the tightest standards in the industry. We safety test, to failure, every batch of axles we produce to ensure they exceed your expectations.

Additional information

Weight 0.3125 lbs


Robert Axle for Kid Trailers replaces your stock thru-axle so you can attach a child or cargo trailer to your 12 mm thru axle equipped bike.

  • This axle is compatible with Burley, Carry Freedom, Chariot/Thule, Croozer, Instep, and many more hitch style trailers.
  • The diameter of this axle is 12 mm and the true length of the axle shaft is 184 mm. Spacers included for a 169, 175, or 184 mm fitment. 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 12×148 hub does not equal a 148 mm long axle. We suggest a +/- 2mm axle length fit is perfect for all our axles.
  • This axle has a 1.0 mm thread pitch.
  • The axle shaft and axle end are precision CNC machined.
  • The axle shaft is 7075 aluminum and hard black anodized for rugged durability.
  • The axle end is stainless steel, which allow for mounting of the hitch provided with your trailer. The threads are M10x1 (metric).
  • Hardware for attachment of the hitch is included; the hitch is not.
  • No special tools required. Design allows for installation or wheel removal using your standard 5mm hex wrench.
  • Designed, built and quality tested in the USA. Proven around the world.


Need more information about how our axles work?

28 reviews

  1. Joel

    Great solution to using a modern bike for a trailer hauler! Why trailer companies haven’t progressed is beyond me. Works flawlessly with my Thule child trailer.

  2. Kruse Markus (verified owner)

    Fits perfectly with my Trek Rail 7. Top quality, very fast shipping! 👍🏻💪🏼

  3. Chad Stronge (verified owner)

    Worked great. Installation was simple, shipping was so quick! Tha Canadian money conversion with shipping made it pretty expensive but it solved my issue.

  4. Derrik Schweppe (verified owner)

    Love this! Now I can pull my kids around the neighborhood on my bike. They love it! Seamless install, super easy to use.

  5. Stephan (verified owner)

    fits perfectly, was shipped within 3 days to Germany. thanks for this awesome service!

  6. Fredy monsalve (verified owner)

    After purchasing the 12mm thru axle for my daughters chariot it has a few issues. After greasing the axle and replacing it with my original axle I could not get it to losen up even tho I greased it and put it to the correct torque it would not let go. The 5mm hex option stripped the end and now I’m only left with my jaw locking pliers which is kind of a pain. Wish they had a different option like using a wrench.

  7. Fredy Monsalve (verified owner)

    Wow I’m speechless in less then 10 hours they wrote back to me and are replacing my axle under warranty. I can honestly say this caught me by surprise. Amazing customer service from these guys!!!! Keep it up guys

  8. Adam Reininger (verified owner)

    Awesome! Works great with my Thule Chariot (double) and my 2020 Trek Rail 7. Took the kids on long ride last weekend and they had a blast. Thanks for making such an amazing product.

  9. Dmitry

    5-star service throughout the whole journey.
    1) I got the consultation through email. I was waiting not more than 15 mins for answers.
    2) I got my order verified quickly.
    3) The delivery was really fast.

    I would recommend The Robert Axle Project to everyone.

  10. Asher Vitek (verified owner)

    I was super pleased to find this. We had been looking for a solution to pulling our chariot on my bike and this nailed it. Used the axle finder to get the exact axle I needed.

  11. Ramon Brendel (verified owner)

    Very happy – ordered from Germany and recieved within 4 days – fits perfectly with my Scott e-fully – thx

  12. Pete Wachowiak (verified owner)

    Works great on my Trek Rail! So glad to find this.

  13. Stefanie (verified owner)

    Im impressed. The search tool is so easy to use and accurate and found the exact part I needed. Even my local dealer told me there was nothing to do to attach a child trailer to my mountain bike and here the RAP has saved the day! Thank you!

  14. Johanna (verified owner)

    Works perfectly with my Canyon Spectral:ON. The axle was easy to install with clear instructions – even for me! The shipping was amazingly fast. Great customer experience overall, I highly recommend!

  15. Steven (verified owner)

    Very surprised about the great fit and high quality of the axle. Very happy I went with RAP.

  16. Larissa (verified owner)

    Fits perfectly on my Trek Rail 5. Ordered it from Switzerland and recieved within a few days. Very glad to find this axle. Thanks!

  17. Steve Howson (verified owner)

    Tell them what bike you have and they’ll send you the axel you need. They guarantee it. Installation was easy.

  18. Teemu Mikkonen (verified owner)

    Lightning fast delivery and a great product.

  19. Maxim Cloutier (verified owner)

    Great product. Fairly simple to install for soemone with little knowledge working on bycycles. Fits perfect and shipping was super fast. Thank you for the great product and service!

  20. Arto (verified owner)

    Shipment was fast. instructions were good and detailed. axle fit perfectly to my Trek Rail 5.

  21. Christian Jæger Denmark

    Genius. Plain and simple.

  22. Tyler Knibbe (verified owner)

    I was super frustrated trying to find the right axle that would work with my bike and Thule Chariot. I spent hours on the internet and phone trying to find the right specs, thread count, and trying to understand something I never have dealt with before. I finally reached out to a buddy that knows bikes better, and he immediately recommended Robert Axle Project. 10 minutes later the axle was on its way due to their awesome Axle Finder app. It was on my bike a couple days later and I was cruising around town with my boy. I just wish I knew about them before…

  23. David DeWeese (verified owner)

    Great product, so glad I found your company! I bought a 2021 Trek Fuel EX 8, and wanted to continue to tow our two boys in our Burley Bee. Your axle fit perfectly, did it’s job! Will recommend to anyone in need.

  24. Christian (verified owner)

    Great product and great service. ÅFits my 2021 Haibike Allmtn 6 with Thule Chariot kid trailer. Bike was not listed in axle finder app, but order was manually checked. They even asked for specs and pictures of original bike axle so they could add it to their database.

  25. Marco (verified owner)

    Super Service und passt perfekt für mein Lapierre Overvolt 6.6👍🏻
    Der Versand hat 2 Tage gedauert

  26. Eric (verified owner)

    The axle works perfectly for my Trek Rail 7. The Thru Axle Finder was easy to use and the axle is very high quality.

  27. Eric (verified owner)

    Perfect fit, easy to install. Very clear instructions.

  28. Robert (verified owner)

    High quality, light weight. Perfectly fit for my Haibike. Fast shipping to Norway.

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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: $21.50 USD, 10-14 business days

• All other International: $21.50 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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