SRAM XX1 X-Horizon Rear Derailleur
With its "horizontal parallelogram" design and pulley offset, X-HORIZONTM 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 CLUTCHTM technology reduces bounce and chain slap. CAGE LOCKTM technology makes wheel removal and installation easier than ever before. Paired with the XX1 shifter, the X-HORIZON RD forms the backbone of X-ACTUATIONTM technology for unbelievably smooth shifting action.    Large upper pulley offset automatically adjusts chain gap    Straight parallelogram design with horizontal movement reduces shift force and improves drivetrain performance    12T X-SYNC pulley wheels    TYPE 2 technologies: ROLLER BEARING CLUTCHTM and CAGE LOCKTM    New silent pulley tooth design    Weight: 220 grams