Axle Kits include a replacement Steel Axle, End Cap, and End Cap Seals. 

• 148mm Axle Kits are compatible with 148x12mm Boost, and 148x12mm DH hubs. 
  
• 157mm Axle Kits are compatible with 157x12mm Super Boost, and 157x12mm DH hubs. 

15mm Aluminum axle kit for Sidekick GR and Gen 1 hubs. 17mm Aluminum axle kit for Sidekick Gen 2 and Sidekick Pro Hubs. No cross-compatibility between generations.