Shimano Hollowtech cranks have been the best cranks you can put on a mountain bike. Extremely strong, remarkably lightweight, and stiffer than a straight shot of whiskey. The crankarm construction exemplifies the level of craftsmanship that's put into a Shimano crankset, utilizing a 3D hollow bonded structure to further reduce weight and increase stiffness. Chainrings are easily exchanged with the new direct-mount system and the cranks can be swapped between single and double front chainring setups. 

Features
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

Specifications
Q-factor: 181mm
Chainline: 56.5mm, works with 157 O.L.D.
Compatible Bottom Bracket Type: Outboard
Compatible Chain: HG 12-speed
Bolt Circle Diameter: 96mm asymmetrical 4-bolt (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

Mfr Claimed Weight
636g