TheShimano Deore XT FC-M8000 11 Speed Chainsetis a performance mountain bike chainset is designed for use with Boost 148 axles / 53.4mm chainline. Shimano Deore XT FC-M8000 11 Speed Chainset Without Ring Features Forged HollowTech II aluminium cranks offer unrivalled strength-to-weight ratio Lightweight construction for external super smooth bottom bracket bearings Steel inner ring combined with a thicker aluminium and carbon composite Hollow outer ring for excellent rigidity and durability Close ratio gear combination for minimum shifting gap provides improved cadence while reducing pedal feedback on suspension bikes Available in 36-26T Plus 3 mm outboard chain line (53.4 mm) for use with 148 mm rear axle width HG-X chainring with patented spike pins give smooth and fast gear shifts under load 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 11-speed HG-X MTB chains only We recommend that the bottom bracket is initially installed by a bike shop to ensure perfect bottom bracket facing and fit