The Shimano XTR M9100 is designed to withstand full force pedalling on the roughest trails, with smooth shifting and exceptional chain stability. It offers enhanced shifting performance, a low profile design, and low sprocket compatibility.-Designed with a Shadow RD clutch to reduce chain slap and create a quiet drivetrain with less distraction-Decreased rear derailleur tension at low gear positions prevents high chain tension-Features a larger 13-tooth pulley-For use with 1x11 and 1x12 set ups, but only up to a 45-tooth cog