Maximum ImpactWith its horizontal parallelogram design and pulley offset, X-Horizon keeps the chain gap constant across all 11 gears, giving 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 X-Horizon RD forms the backbone of X-Actuation technology for unbelievably smooth shifting action.Large upper pulley offset automatically adjusts chain gap,X-Horizon design reduces shift force and ghost shifting,12-tooth X-Sync pulley wheels,Type 2.1 technologies: Roller Bearing Clutch and Cage Lock,New silent pulley tooth design.