Why Do XT Riders Choose the Shimano BB-MT801 Bottom Bracket?

The Shimano Deore XT BB-MT801 is the threaded English bottom bracket engineered specifically for Deore XT M8000 and M8100 Hollowtech II cranksets, using high quality sealed bearings positioned outboard of the frame shell per the Hollowtech II standard. The outboard bearing position maximizes the effective bearing span, improving lateral stiffness and distributing pedaling loads more efficiently than traditional threaded designs with inboard bearings. Shimano specs the BB-MT801 with high quality sealed bearings tuned for the higher power loads and more demanding trail conditions typical of XT-level riding.

English threaded BSA shell, compatible with both 68mm and 73mm shell widths. Designed for Shimano's 24mm hollow crank axle standard used in XT M8000 and M8100 cranksets, and mechanically compatible with other Shimano Hollowtech II MTB cranksets. Installation requires a Shimano TL-FC36 or equivalent Hollowtech II BB wrench. Shimano offers the BB-MT801 in both threaded and press-fit options -- this is the threaded English version. For riders building or maintaining a Deore XT drivetrain on a threaded English frame, the BB-MT801 is the correct OEM bottom bracket.