A high performance chainset from the classic ATB group offering the most advanced features Forged Hollow Tech II aluminium cranks offer unrivalled strength-to-weight ratio Lightweight construction with external super smooth bottom bracket bearings for efficient use SG-X anodized aluminium chainrings deliver a smooth precise shift Stiffness & strength increased with advanced design due to wider spaced bearings & oversized axle 48 / 36 / 26 tooth 9-speed chainrings We recommend that this bottom bracket is initially installed by a bike shop to ensure perfect bottom bracket facing & fit Comes complete with bottom bracket for 68 & 73 mm frames Weight: 853 grams for M770 in 175 mm