Class-leading XTR 12-speed double chainset, integrating the bottom bracket and crank set into a strong, rigid, yet lightweight unit Direct mount chainrings are lightweight and easy to replace while providing increased rigidity Integrated bearing preload design is lightweight and makes installation and adjustments easier than ever Super-lightweight HollowTech II cold forged Duralumin crank arms - hollow design saves weight whilst increasing rigidity and durability Easy to use splined bottom bracket spindle connection provides a rigid and secure interface between crank and spindle With a 51.8mm chain line (boost) and a 168mm Q-factor ideally suited for all-mountain and to be used in conjunction with 10-45T cassette crank set supplied without bottom bracket and chainrings Compatible with all 12-speed direct mount XTR chainrings For use with 12-speed HG+ chains only