The SHIMANO DEORE XT FC-M8130-1 crank features an entirely new construction using direct mount chainrings special gear tooth profile for improved chain retention and a 181mm Q-factor. Special MTB gear teeth profile improves chain engagement and retention Hollow forged crank maximizes power transfer while limiting weight Superior chain retention Rigid and lightweight design for aggressive trail riding Q-factor 181 mm Chainline 56.5 mm 157 mm O.L.D.