The Shimano Deore XT FC-M8130 12 Speed Crankset without Ring are forged HollowTech II aluminium cranks that offer unrivalled strength-to-weight ratio. Shimano have created these cranks with a lightweight construction for external super smooth bottom bracket bearings. Shimano Deore XT FC-M8130 12 Speed Crankset without Ring Features For use with 12-speed Dyna-Sys DCE single chainrings SM-CRM85 DCE chainrings are available in 28T, 30T, 32T, 34T and 36T Super boost 56.5mm chain line for use with 157 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