Shimano FC-M8120-1 XT Boost Crank Arms - 12 Speed

55mm chain line works with 148 O.L.D. Prioritizes frame and tire clearance over Q-Factor

Special MTB gear teeth profile improves chain engagement and retention
Hollow forged crank maximizes power transfer while limiting weight
Superior chain retention
Rigid and lightweight design for aggressive trail riding
Q-factor: 178mm
Chainline: 55mm chain line works with 148 O.L.D. (Prioritizes frame and tire clearance)
Compatible Bottom Bracket Type: Outboard
Compatible Chain: HG 12-speed
Bolt Circle Diameter: Shimano Direct Mount spider
Chainring sold separately
Rear Speeds: 12
Recommended Bottom Brackets: BB-MT800-PA (Pressfit); BB-MT800 (Threaded)
Bottom Bracket sold separately
Threaded BB Shell Width: 68/73mm
Weight: 616g.