The shimano xtr m9000 race 3828 11 speed double chainset is ideal for those who value lightweight strength and a wider gear range on their cross country bike these class leading cross country race focused cranks are compatible with xtr 1x or 2x chainrings on its narrow 158mm q factor crankarms the crankarms are made from a carbon aluminium construction with a 3d hollow structure to increase stiffness and minimize weight the outer chainring is made with a titaniumaluminium composite hollow 3