SRAM Rival 1 Rear Derailleur - 11 Speed Long Cage Black/SilverSRAM Rival 1 Rear Derailleur 11 Speed Long Cage Black Silver. The 1x specific X Horizon derailleur design provides excellent chain control and shifts well regardless of cassette size. Roller bearing clutch and parallelogram design combine to minimize chain bounce making the drive train safer and quieter over rough terrain Not compatible with multiple chainring drive trains TECH SPECS Rear Derailleur Mount Type 10x1 Standard Rear Der Shifter