The Shimano Deore M6100 12 Speed 52mm Chainset is an excellent value 2-piece chainset for 12-speed Dyna-Sys MTB HG-X transmissions. The HollowTech II integrated bottom bracket design uses a wide bearing placement with a large axle diameter for increased stiffness, efficiency and added durability. Shimano Deore M6100 12 Speed 52mm Chainset Features Forged crank arms rigid whilst being incredibly strong and durable Lightweight aluminium chainring We recommend that the bottom bracket is initially installed by a bike shop to ensure perfect facing and fit 52 mm chain line for use with 135 /142 mm O.L.D. frames Direct mount chain ring 12-speed Dyna-Sys compatible