Want to make your bike faster than any other? Had enough of servicing your ceramic bearings so that they will survive another rainy day race? Would you rather have a bottom bracket outlast your frameset? Then you have arrived at the solution. XD-15 ceramic bearings have it all – hands down the speediest, and longest lasting ceramic bearing available on the market. Nitrogen steel is the secret, precision machined and ground to ABEC-5 tolerances at Enduro's facility in Gilroy, California. Voted “Hands down the best bottom bracket we have ever tested” from Bike Radar, you can find out why. These bearings spin with the very least resistance of anything developed to date featuring oversized Grade 3 Silicon Nitride balls. On top of this, they will be spinning with the same ease one year or even two years from now, with longer intervals between servicing. No one else in the bicycle industry offers this combination of speed and durability: XD-15 bearings for wheels, bottom brackets, and drive train.