With its horizontal parallelogram design and pulley offset, the Sram XX1 Rear Derailleur Type 2.1 11 Speed keeps the chain gap constant across all 11 gears, providing fast, precise shifts. By limiting all movement to the horizontal axis, this design is faster, reduces shift force and eliminates ghost shifting. ROLLER BEARING CLUTCH technology reduces bounce and chain slap. CAGE LOCK technology makes wheel removal and installation easier than ever before. Paired with the XX1 shifter, the Sram XX1 Rear Derailluer Type 2.1 11 Speed forms the backbone of X-ACTUATION technology for unbelievably smooth shifting action.