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. 77 grams.
A guide to bottom bracket standards.