Shimano XT M8000 Triple Chainset A high performance chainset from the classic MTB group, using the most advanced 11-speed Dyna-Sys chainrings Forged Hollow Tech II aluminium cranks offer unrivalled strength-to-weight ratio Lightweight construction with external super smooth bottom bracket bearings for efficient use Hollow chainrings using drilled steel & carbon composite construction middle ring, combined with a thicker aluminium & carbon composite outer ring, & plated aluminium inner ring for excellent rigidity & durability Close ratio gear combination: 40-30-22T provides enhanced cadence while reducing pedal feedback on suspension bikes HG-X chainring with patented spike pins give smooth & fast gear shifts under load Stiffness & strength increased with advanced design due to wider spaced bearings & oversized axle 70 degree spider arm for optimal rigidity For use with 11-speed HG-X MTB chains only We recommend that this bottom bracket is initially installed by a bike shop to ensure perfect bottom bracket facing & fit