Shimano SM-BB92-41B is a bottom bracket for press-fitting Hollowtech II cranks into a road frame with 86.5 mm bottom bracket shell. Hollowtech II means the axle diameter is 24 mm, which benefits the rigidity and resilience. Use this bottom bracket, which is characterized by its weight-saving small ball bearings, best in combination with a Dura Ace 11-speed crank.
Small ball bearings for low weight
Recommended for Dura Ace FC-R9100, FC-R9100-P, FC-9000