Shimano's Deore XT M8100 12-Speed Single Crankset uses an entirely new construction, with exchangeable direct mount chainrings matched to their proven Hollowtech 2 bottom brackets (sold separately) to create a lightweight, strong and great value crankset.Forged HollowTech II aluminium cranks offer unrivalled strength-to-weight ratioLightweight construction for external super smooth bottom bracket bearingsFor use with 12-speed Dyna-Sys DCE single chainringsSM-CRM85 DCE chainrings are available in 28T, 30T, 32T, 34T and 36T52mm chain line for use with 142 / 148 mm rear axle widthStiffness and strength increased with advanced design due to wider spaced bearings and oversized axle70 degree spider arm for optimal rigidityFor use with 12-speed HG+ MTB chains onlyShimano recommend that the bottom bracket is initially installed by a bike shop to ensure perfect bottom bracket facing and fitThe Deore XT M8100 uses Shimano's long-standing Hollowtech II construction, giving you a crankset that is lightweight, stiff and incredibly durable. They are also a breeze to install and maintain. The versatile direct mount chainring design means you can quickly and easily swap between double or single chainring combinations, boosting the cranksets versatility. This version is sold as bare crank arms, so you can choose the chainring ratio to suit your bike, riding style and terrain. Lightweight, durable and versatile, the Shimano Deore XT M8100 12-Speed Single Crankset is perfect for any mountain bike designed to get out in the wilds on rugged terrain.