Speed. It is ultimately why we ride. If you want to make your bike faster, more reliable and virtually maintenance free in all conditions, look to the XD-15 bottom bracket. Precision ground and USA made at the Enduro Bearings facility in California, the XD-15 combines cryogenically treated nitrogen steel races with Silicon Nitride Grade 3 ceramic balls in a proprietary process that results in the ultimate high performance bearing setup. Find out why Bike Radar reported the XD-15 “Hands down, the best bottom bracket we have ever tested”. We are so sure that you will love these bearings we offer an unlimited 2 year bearing and race warranty.