The C157 is a purpose-built hub for 12 x 157 Super Boost Bikes. The 157mm spacing allows us to extend the flanges out and give you wider flanges for a better bracing angle. This is important because a wider bracing angle builds into a stronger wheel and a stronger wheel means you can ride with confidence and control. Compatible with Shimano Hyper Glide, Shimano Micro Spline, Campy or SRAM XD/XDR this hub is ready to hit the dirt.