Time to service your mountain bike's drivetrain? The bottom bracket is the heart of it all, and this Shimano Deore XT BB-MT800 is a top-tier choice. It's the Hollowtech II design, which means it's the external bearing style that works with all Shimano Hollowtech II cranksets (like the popular XT, SLX, and Deore series).
It's a BSA threaded model, which is the standard screw-in type found on most traditional mountain bike frames. The shell width is 68mm or 73mm—this one fits both, so it's perfect for the vast majority of hardtails and full-suspension bikes. The cups are aluminum to save weight, and the bearings are sealed and smooth.
This is an OEM-level part from Shimano's high-performance XT line. It comes with the two adapter cups, the bearings, an inner cover, and even the Shimano TL-FC25 installation tool. Swapping in a fresh BB like this can make your cranks spin noticeably smoother and quieter, eliminating creaks and play.
If your bike has a threaded BB shell and Hollowtech II cranks, this is the direct replacement you need for a reliable, high-performance rebuild.
Free 30-day returns 
Free 30-day returns
