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. FEATURES: 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 Will accommodate up to a 51-tooth cog SPECS: Largest Cog: 51 Rear Derailleur Mount Type: 10x1 Standard Chain Wrap Capacity (teeth): 41 Cage Length: Long Rear Der/Shifter Compatibility: Shimano Mountain Drivetrain Speeds: 12 Weight: 240g