Sram RD Rival Long Cage 1X11 SpeedFeatures Dedicated 1x rear derailleur for efficient and reliable shifting Exact Actuation provides fast and accurate shifts with SRAM's 1: 1 actuation ratio X Sync pulley with 12 tooth design controls chain movement for smoother shifts Roller Bearing Clutch technology ensures consistent chain tension X Horizon design eliminates ghost shifting and reduces shift effort Cage Lock technology enables quick wheel changes and chain installation