The Shimano Deore FC-M6100-1 crank features an entirely new construction, using direct mount chainrings, special gear tooth profile for improved chain retention, and a 178 mm Q-factor that is compatible with 148 mm O.L.D. frames.Great value Deore M6120 2-piece design chainset for 12-speed Dyna-Sys MTB HG-X transmissionsForged crank arms rigid whilst being incredibly strong and durableHollowTech II integrated bottom bracket design uses a wide bearing placement with a large axle diameter for increased stiffness, efficiency and added durabilityLightweight aluminium chainringWe recommend that the bottom bracket is initially installed by a bike shop to ensure perfect facing and fit55 mm chain line for use with 148 mm O.L.D. framesDirect mount chain ring12-speed Dyna-Sys compatible