Thunder Bolt-On Rear Axle – 12mm x 229mm x 1.75

Thunder Bolt-On Rear Axle – 12mm x 229mm x 1.75

(7 customer reviews)

$ 57.00

Designed for big rides and big riders. Our Thunder Bolt-On replacement thru-axles are a strong and durable option to replace your stock through axle. Thunder Bolt-On Axles are NOT for use with a trailer, but are a solid option if you’re looking to replace your stock thru axle with a more durable, lower profile design. If you want a lighter weight axle, then check out our Lightning Bolt-On Axles.

This is NOT an axle for attaching trailers or trainers.

SKU: BOL207 Category:


If you’re tired of having a thru axle that sticks out far past your hub, but you’re skeptical of ultra-lightweight parts, then the Thunder Bolt-On Axle may be for you. Simple, clean, and very strong, these bolt-on thru axles are a perfect alternative to your stock thru axle. Easy to install and remove, too!

If you want a lighter weight axle, then check out our Lightning Bolt-On Axles.

Additional information

Weight 0.3125 lbs


Thunder Bolt-On Axles replace your stock thru axle on your 12 mm thru-axle equipped bike.

  • The diameter of this axle is 12 mm and the true length of the axle shaft is 229 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 12×197 hub does not equal a 197 mm long axle.
  • This axle has a 1.75 mm thread pitch.
  • Weight: TBD
  • The axle is precision CNC machined in the USA from 7075 aluminum and hard anodized for rugged durability. Our axles are built to the tightest standards in the industry.
  • 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?

7 reviews

  1. Scott Bixby

    High quality axle, nice fit and finish. No more creaking caused by the cheap OEM QR axle always coming loose.

  2. Marcel (verified owner)

    The best!!! I exchanged the stock axle on my 9zero7 carbon whiteout because issues with the quick release, this axle could not have worked better. Peace of mind! Highly recommended.

  3. David M (verified owner)

    Great axle. Replaced stock axle on Trek Farley 9.6. Fit is perfect. Recommended!

  4. Mike (verified owner)

    Nicely made – Allowed me to convert my Kona WO fat bike to a through axle! Kona has through compatible drop outs to fit the bike, but do not offer an axle. Was looking around for quite a while before I came across the Robert Axle Project.

  5. Marco DeAngelis (verified owner)

    Awesome product and great customer service!!! Gave me a great solution to thru axle my fat bike.

  6. Dave Katzmann (verified owner)

    Replaced the rear axle on my 907 carbon Whiteout (had issues w the release lever…which have now also happened on my front axle). Got really helpful information prior to ordering, axle works great and has gotten the attention of all my riding buddies who like how clean it looks. Definitely recommend to others…and wish that a front axle fix existed!

  7. Tryon Bike (verified owner)

    Thanks! We needed an extremely unique axle for our fatbikes and Robert Axle Project is the only one who makes it. Super easy to work with and fast shipping. Thanks for hooking us up!

    – The guys at Tryon Bike

Add a review


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.

You Might Also Like:

  • Yes! A 12 mm thru-axle adapter for BOB Trailers! These Robert Axles for BOB Trailers are specifically engineered to attach the proven BOB Trailer to your thru-axle equipped bike.

    Take full advantage of your modern bike with 12 mm thru-axles and harness the rigidity of the thru-axle to haul your BOB Trailer. Set out on any adventure, big or small. Great for off-road tours, trail building, hauling cargo and more!

    Add to cart
  • 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.

    Add to cart

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.