The XTR BB93 takes a cue from Shimano’s top road bottom brackets now featuring smaller diameter bearings to save weight. This new design drops 21g off its ancestor and features a new seal system which reduces friction by 50 The XTR BB93 Bottom Bracket is available with English threads and includes three 2.5mm spacers for use with 68mm and 73mm shells. Compatible with all HollowTech II cranks.