Thanks to its "horizontal parallelogram" design, X-Horizon can keep the chain gap the same across all 11 gears. By taking vertical movement out of the equation, this design doesn't just make shifting faster. It reduces shift force & eliminates ghost shifting. Sram's Rolling Bearing Clutch technology reduces bounce & chain slap, which the Cage Lock technology makes wheel removal & installation easier than ever before. Paired with the XO1 shifter, the Sram XO1 11 Speed Rear Derailleur forms the backbone of X-Actuation technology, the key to totally smooth shifting action.