Shimano XT M770 Crank-Bottom Brackets Sets. Hollowtech II design with outboard bearing bottom bracket. Carbon-Steel middle ring for maximum life
Hollowtech II design maximizes stiffness while keeping weight to a minimum Precision two-piece construction for perfect chainline and chainwheel alignment. 44T-32T-22T Increased stiffness and improved shifting performance Carbon composite/ Steel composite middle ring adds rigidity for better shifting, increases service life, and smoothly delivers powers to the cassette. Outboard bearings maximize stability and stiffness 850grams