The pinnacle of mountain bike drivetrain design, this XX1 rear mech offers simple & fast shifting over the XX1s wide range cassette. Using a horizontal movement the XX1 rear mech is faster while reducing shift force & complete eliminates ghost shifting, Cage Lock With CAGE LOCK technology in the rear derailleur, wheel removal & installation—as well as chain installation—becomes faster & simpler. Just pushing the cage forward to create slack & lock it into place. Roller Bearing Clutch Designed for X0 & X9 families, TYPE 2 rear derailleur delivers maximum drivetrain stability—even through the most punishing technical terrain. With Roller Bearing Clutch™ technology, SRAM TYPE 2 eliminates derailleur bounce & chain slap without sacrificing precision. A one-way roller clutch controls chain tension for consistent shifting Needle bearing Self-lubricating for consistently smooth action 360 degree clutch force for reliability & durability TYPE 2’s clutch force comes factory calibrated by SRAM Consistent shifting feel Maintenance free clutch design X-Actuation Developed specifically for SRAM 1X, X-ACTUATION keeps shifting sharp & consistent across the entire 10- to 42-tooth cassette. X-Horizon This rear derailleur’s “straight parallelogram” design limits all movement to the horizontal axis, which makes ghost shifting impossible while also reducing shift force. For quicker, more exact shifting, the large upper pulley offset design maintains a constant chain gap across all gears. X-Sync A CNC-machined, “wide tooth, narrow tooth” pattern is repeated around the entire XX1 chainring, perfectly mirroring the 1X11 XX1 specific chain’s inner & outer links for maximum control.