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.

Out of stock

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.

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

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

  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

You may also like…

  • BOB107 thru axle

    Thru Axle for BOB Trailer: 217 to 229mm with 1.75 Thread

    $ 69.00
    Add to cart
  • KID-FAT-+-12mm-flat-spacer thru axle for fat bike

    12mm Thru Axle for Kid Trailer

    $ 65.00
    Add to cart