The SRAM XX1 was built with a dedicated 1X design philosophy
- making it simpler, lighter & more durable than any other. No matter where you ride, no matter what you're up against: SRAM XX1. Unstoppable. With its 'horizontal parallelogram' design & pulley offset, X-Horizon 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, reduced shift force & eliminates ghost shifting. Roller Bearing Clutch technology reduces bounce & chain slap. Cage Lock technology makes wheel removal & installation easier than ever before. The 12 Tooth X-Sync pulley wheels perfectly mirror the chain's inner & outer link for maximum control. Large upper pulley offset automatically adjusts chain gap. Straight parallelogram design with horizontal movement reduces shift force & improves drivetrain performance, 12T X-SYNC pulley wheels. TYPE 2 technologies: ROLLER BEARING CLUTCH & CAGE LOCK New silent pulley tooth design. The first rear derailleur of its kind, SRAM TYPE 2 lets you push your cage forward & lock it into place with the push of a button. This creates slack, removing all tension from the chain. With Cage Lock, TYPE 2 makes wheel removal & installation-as well as chain installation-easier than any other derailleur on earth.