The shimano xtr race m9000 11 speed chainset will integrate the bottom bracket making this a strong rigid and lightweight unit that is easy to install and adjust to make the bottom bracket last longer the precise bb bearings are spaced further apart making it much more stable than conventional bottom brackets vital grams are shredded from this crank set thanks to the hollow bonded construction for the lh crank arm this shimano crank set is ideally suited for xc racein