12mm Thru Axle for Kid Trailer

(53 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.

In stock

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SKU: KID212 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.

Prop65 Warning icon

WARNING: This product can expose you to chemicals including nickel acetate, which is known to the State of California to cause cancer. For more information, go to www.P65Warnings.ca.gov.


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 true length of the axle shaft is 165 mm, but can be shorted using the 6 mm spacer for lengths of 159 mm or 165 mm. This allows for axle lengths of 152, 160 or 167 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 142mm long axle.
  • This axle has a 1.5 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?

53 reviews for 12mm Thru Axle for Kid Trailer

  1. Ally M (verified owner)

    Great bit of kit. Works perfectly allowing me to tow our Croozer Kid for 2 trailer with my Shimano 142x12mm E-thru axle equipped hardtail (2016 Genesis High Latitude). Very easy to work out which axle I needed using the sizing guide to identify thread pitch and length needed. Early days as I’ve only used it for one big ride, but very easy to fit. I only intend fitting it when I’ll be towing the trailer as it does stick out quite a bit from the frame but that’s not a criticism (any axle attachment will be the same). It’s not cheap but it IS good value given the design input and high quality of the product. Unfortunately UK customs intercepted it and applied a GBP£11 import charge but that’s just your luck. Thanks.

  2. Timothy Stedman (verified owner)

    This is a brilliant product, both highly durable and perfectly designed. I had it installed on my Curry Tech E3 Dash in under 10 minutes, and felt secure knowing my Allen Sports two kid trailer was firmly attached. The axle selection and installation processes were really simple you guys. Nice job!

  3. Alex (verified owner)

    Worked great for burley trailer on my Raleigh Stuntman. Customer service answered questions quickly before ordering. Very well built.

  4. Charles (verified owner)

    Works great. Have a Jamis Renegade Expert (2017) – using this to tow a burley d’lite.

  5. Yoann Briant (verified owner)

    Wonderfull solution: perfect fit (with selection tool on-line), high quality, handy solution for fast replacement with original axle without removing the kid trailer kit from the axle.
    I use it for Thule Chariot Cx 1 and 2 on a cyclocross bike. This is the best choice you can make as even Thule’s one didn’t fit well. The Robert axle one is the perfect customized solution.

  6. Kevan (verified owner)

    Exactly what I was looking for!

    I recently purchased a new bike with disc brakes and threw axels and could not find a way to attach my child’s wagon without damaging the carbon frame.

    The product is designed and built very well and is easy use and swap back and forth with the stock axel. I would certainly purchase this again and would recommend to anyone looking for a secondary axel that is very reasonably priced. Instructions were very easy to follow I had zero issues with the install or use.

  7. Jonathan (verified owner)

    When my Project Hero Sponsors proposed upgrading my 2007 Cannondale Optimo 3 with a 2017 SCOTT Solace 10 Disk, my chief concern was finding a through axle attachment to still tow my children in the Allen Sport XLT-X2 Trailer. The product sent by Robert Axle is stronger than my stock axle, has the exact same thread pitch, came with detailed installation instructions, and worked perfectly, while not damaging my carbon framed bike. Definitely worth the investment.

  8. Dr Benn Gooch

    Bought through the UK supplier SJS Cycles. I spent a long time researching the right Thru Axel for my Vitus Substance V2 gravel bike (available online through Chain Reaction Cycles). I downloaded the size guide and checked thread size. I was nervous the axle wouldn’t fit – but it fits perfectly. Looking closely at the product you can see it has been very precisely milled and the finish is very high quality. Have to say £55 for an axle is fairly expensive but as you guys are the only manufacturer of this type of bespoke product I was prepared to spend the money to get the right product for safe travel with by children’s trailer. Keep up the good work. Might buy the t-shirt next. Happy riding.

  9. Chris Bozman (verified owner)

    This just works, Simple process, and a simple axle that works and fits my bike. Not much more to say! if you need a 12x axle for a kid trailer just buy one and it will work.

  10. Dave C (verified owner)

    This gets the highest praise for something like a thru-axle — you don’t even think about it. Allows me to attach the hitch cup for my Thule Chariot trailer with no penalty in functionality or weight. Towing a Chariot Lite behind an aluminum gravel bike, for reference.

  11. Nicholas (verified owner)

    Excellent purchase, got this for my Rocky Mountain Solo 2018. Fit was prefect and customer service was top class. Keep doing what your doing guys.

  12. Betsy Binish (verified owner)

    This has worked great on my Kona. Simple to install and worked great for my equipment. So glad i found this and can enjoy bike rides with my kidos!

  13. Peter W (verified owner)

    Burley did not offer a thru axle for my 2019 Kona Sutra LTD and pointed me to Robert Axle. It fits great and works well.

  14. George L (verified owner)

    Exactly what I needed. I got a Burley Bee trailer to haul my dog around in, and since I already had Robert Axle Project axles, this was a perfect drop-in replacement.

  15. Simon Kurtz (verified owner)

    I replaced the axle on my 2019 Kona Sutra to pull an Instep Take 2 Kids trailer, and it worked perfectly. Take note that if you connect that trailer, the tab doesn’t have a place to fit like you would on a dropout. The craftsmanship on the axle was superb. The printout to identify the current axle to determine its replacement worked very well as well. Thank you for those easy steps.

    An improvement that I think could be made would be to supply to smaller washers rather than one large one. As it stands, the axle’s threads extend just a couple millimeters, but that’s not a functional problem whatsoever.

    The shipment was processed the same day I ordered and arrived very quickly. Thank you so much for that as I was in a bind to get it quickly prior to an upcoming trip. It’s now been road-tested and performed flawlessly.

  16. Juho M (verified owner)

    Works perfectly for my Kona Rove NRB 2020 with Thule Cheetah. Shipped fast overseas to Finland.

  17. Adam (verified owner)

    This axle was a god send for us. We purchased a Chariot Chinook then decided to buy a brand new Giant Revolt to bring our little one on adventures with us. You can imagine our dismay when we found out that our new Giant has a thru axle and Thule had their adapter axle on back order until at least the end of the season. We were just about to give up, return our new bike and sell our kid trailer, when I discovered the Robert Axle Project. Wow, these folks are designing great products. It was more affordable than Thule’s axles and really easy to install. I’m very impressed by R.A.P. and will highly recommend you guys to anyone who asks. It’s no wonder that all the reviews are 5 stars. Great job, thanks so much.

  18. Alex (verified owner)

    My only bike without disc brakes was an old road bike with 25mm tires that I was using for a Schw*nn Rascal trailer to get my puppy to the dog park. I bought this thru axle for my “urban adventure” bike and am way happier getting her to the park now.

  19. Joey S (verified owner)

    Great Axle kit!! perfect fitment, easy installation, strong and reliable. great quality!!

  20. Mauricio Candamil (verified owner)

    I have a Giant Revolt Advanced 2021 and this thru-axle for kid trailers worked perfectly for our Aosom dog trailer. Recommended!

  21. Paul Webb (verified owner)

    Excellent service … axle works as it should … quick service … would recommend … in fact I’ve listed them as a sponsor for my trip to my 50th yr. High School Reunion …. California to New Jersey – summer 2021. Thanks everyone at The Robert Axle Project – Cheers! Paul Webb

  22. Eric Chon (verified owner)

    Worked a treat! Easy to install and now I can drag the kiddo around on the gravel bike 🙂

  23. Raz (verified owner)

    Excellent quality, easy to install with simple yet complete instructions.
    Delivery was quick, and all information was available to get the right axle for my Marin DSX.

  24. Jacob W (verified owner)

    Happy overall with the product and support.

    I ordered the axle for a Ridley X Trail Carbon after verifying the fit on the website. When I received and verified the fit, the product was **slightly** outside of the recommended length tolerance. I emailed Robert Axle with pictures and measurements. They responded promptly, informing me that it was still safe to use the axle. After a couple rides, I have no complaints. Great US made product.

  25. Pablo León (verified owner)

    Perfect fit on my Kona Sutra, the 2 mm extra that stick outside the frame fall well within what has already been posted and specified by manufacturer. Already tried it with the trailer and it all seems ok so far.

    Shipping to Chile was fast and clear all along, as were the instructions to install it. Would definetely recommend. Thank you!

  26. Alex J (verified owner)

    Exactly what I was looking for. It works perfectly. The challenge for me was to hook a Thule Chariot Cab 2 trailer to my Rondo Mutt AL bike. Very easy installation and top result!

  27. Brandon (verified owner)

    The axle has worked well with our 2020 Burley Bee and 2021 Kona Sutra LTD. I would recommend this company if OEM solutions are not available. In my case, Burley didn’t have a thru axle designed for my bike. The torque specs are higher on this thru axle than the bike axle on my bike. An interesting, and subtle difference.

  28. Daniel Charbonneau (verified owner)

    The axle works perfectly with out Thule trailer. Easy install, quality materials and finish. Ordering was quick and easy as was the shipping.

  29. Marcus (verified owner)

    I’m very impressed with this. Robert Axle carries a wide variety of sizes and threads. The one I purchased was 2 mm short of what I removed, but it is within Robert Axle’s recommended applications. It went together easily and I have not experienced any issues with it. I like having the nut to hold the hitch better than the compression using a QR axle. This is a great product!

  30. Marcel (verified owner)

    Perfect fit for my Masi Supremo. 100+ miles and counting towing my 40lb pooch around town.

  31. Fredrik (verified owner)

    Super professional staff helpt me to get the right size. Thanks again Robert axle project👍

  32. Unai De la Llana (verified owner)

    I was looking for an axle for a kid trailer and all the support to find the correct axle was briliant. Now I am using it in my Orbea Terra H30 and it fits perfectly.

  33. Moses Rifkin (verified owner)

    I was trying to connect a Burley Bee to my 2020 Giant Contend AR 1. Not only was this the perfect fit – though you should check to confirm – the Robert Axle customer service was incredibly helpful. I’ll definitely turn to them for all future axle needs!

  34. Matt (verified owner)

    Great product, works exactly as described. Can’t ask for more

  35. Erik Deister (verified owner)

    Axle is nicely made and the hex end let’s you tighten the axle down like normal. That’s a big bonus for me.

  36. Robert W Baumann (verified owner)

    Great piece. it fit perfectly with the provided spacer. kids have been loving the rides. This isnt a fault but one think i think could improve it is there was some way to lock the bracket in place. as of now the bracket is only held at the correct angle though the tightness of the bolt, and not the tab as when it is on the frame.

  37. Brittany Alldritt

    The axle works great. Easy to use,. No safety concerns. We used it for a dog trailer which our 20 lbs dog sat in. Installed on a Ribble CGR AL.

  38. Dany Martineau (verified owner)

    Installed on a Ribble CGR AL with the 3mm spacer and it fits well. Great product.

  39. Tomi (verified owner)

    Installed this on my Kona Libre, attached a Thule Charriot Cross to it, fantastic product, Opens the world quicker for the little one! Immensely fast delivery overseas, good service and easy realiable ordering process.

  40. Garin Hatch

    Used the axle finder feature to select the axle. Everything fit and went smoothly. Installed it on my Poseidon X after a thru axle upgrade. Everything is great!

  41. M Wallach (verified owner)

    I have a 2022 Giant Revolt and this allowed us to mount our Schwinn trailer. We couldn’t be happier, thanks RAP!

  42. Ronnie (verified owner)

    I ordered this thru-axle for my bike, a 2021 Giant Revolt Advanced to use with my Burley Minnow trailer. I cannot recommend this product enough – being a complete bike newbie but with a trailer and trying to select the right product was a challenge until a few of my research sources pointed me to Robert Axle Project’s.

    Product Selection: The selection of the product itself was easy enough, just need to make sure you know what your bike specs are and the online tool they have will guide you true.

    Product: The product itself is great! The axle was sturdy and comparatively light; even when compared to the original thru axle that came with the bike. Installation was simple and unlike other thru-axles I used previously, this one fit just right.

    Order + Delivery: My thru axle was delivered to me in about roughly a week’s time. Product was not damaged in shipping, the package that it came in ensured that.

    Everything you needed and nothing you don’t. Overall, a happy and satisfied customer. Looking to order a couple more really well made, high quality items from them in the near future.

  43. D Kusturiss (verified owner)

    Works great and feels very secure. Very easy to swap out.

  44. Kyle (verified owner)

    Works as expected! Had fun lugging my kid around in my Chariot. The part picker was extremely helpful.

  45. Gabriel

    It functions as designed. I highly recommend it.

  46. Carl (verified owner)

    Works perfectly and as advertised. Fits into my new T-Lab X3 and my double wide Chariot. Love being able to pull the twins around on my gravel bike with a quick and easy swap of the axle.

  47. Loran (verified owner)

    There online tool made it easy to find the right adapter for my bike. Much better than buying directly from the trailer manufacturer. Easy install and works as expected.

  48. Bill Hayes (verified owner)

    I have a Petsafe dog trailer and didn’t know if the axle for the kid trailer would work, but I was assured it would, and by golly, it did. I’m pleased as punch.

  49. Joe D (verified owner)

    Super easy to install, fast shipping, excellent customer service in confirming the right part. Highly recommend!

  50. Felix (verified owner)

    Top notch quality and fit on my Giant Revolt 2020 to connect our Thule Cross 2.

  51. Niall Filewod (verified owner)

    My second Robert Axle Project purchase — just as precisely machined as the first! Allows me to haul our Thule Chariot Cougar 2 with my MEC Provincial Road 233. I know you don’t want to spend money on an axle but just do it already — it’s a great product and you won’t regret it.

  52. Dan J (verified owner)

    Kicking myself for not buying this sooner! Excellent customer service, superb product, fast shipping. Wish I was installing a trailer on another bike so I could purchase from The Robert Axle Project again!

  53. John Low (verified owner)

    Fits and works perfectly. I would recommend these guys to everybody.

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