Description XT has gone 11-speed, and the new Shimano XT Cranksets are spinning on XTR/Dura-ace inspired bottom brackets. They have a smaller bearing size to enhance rolling efficiency and for shaving some weight. They are also better sealed to reject whatever muck mother earth conjures up and tries to throw at them. SHIMANO XT BB-MT800 BOTTOM BRACKET Small Ball Bearings for Better Rotation Better Sealing Fits threaded 68/73mm BB Shells
