The Shimano M770 XT Hollowtech 2 Chainset is a high performance chainset from the classic ATB group offering the most advanced features. Forged HollowTech II aluminium cranks offer unrivalled strength-to-weight ratio. Lightweight construction with external super smooth bottom bracket bearings for efficient use. Drilled steel and carbon composite construction middle ring combined with a thicker aluminium double anodized 44 tooth and plated aluminium 22 tooth ring for excellent rigidity and durability. SG-X chainrings delivering a smooth precise shift and are HyperDrive compatible. Stiffness and strength increased with advanced design due to wider spaced bearings and oversized axle. 44 / 32 / 22 tooth 9-speed chainrings for a wide gear ratio range. We recommend that this bottom bracket is initially installed by Evans to ensure perfect bottom bracket facing and fit. Comes complete with bottom bracket for 68 and 73 mm frames. Weight: 853 g for M770 in 175 mm.