TheShimano Deore XT FC-M8100 12 Speed 52mm Crankset without Ringuses forged HollowTech II aluminium cranks that offer an unrivalled strength-to-weight ratio. ThisShimano Deore XTcrankset is designed for use with 12-speed Dyna-Sys DCE single chainrings. Shimano Deore XT FC-M8100 12 Speed 52mm Crankset without Ring Features Lightweight construction for external super smooth bottom bracket bearings For use with 12-speed Dyna-Sys DCE single chainrings SM-CRM85 DCE chainrings are available in 28T, 30T, 32T, 34T and 36T 52 mm chain line for use with 142 / 148 mm rear axle width Stiffness and strength increased with advanced design due to wider spaced bearings and oversized axle 70 degree spider arm for optimal rigidity For use with 12-speed HG+ MTB chains only It is recommended that the bottom bracket is initially installed by a bike shop to ensure perfect bottom bracket facing and fit