The SRAM X1 11-Speed Type 2.1 Rear Derailleur is a premium, trail-proven mechanical rear mechanism optimized exclusively for 1x11 mountain bike drivetrains. Registered under SRAM Model ID RD-X-1-A2, it borrows the top-tier "one-by" engineering architecture of high-end XX1 groupsets but uses slightly more robust aluminum cage materials to remain cost-efficient.

Note: Although some retailers list this component under a "long cage" description, SRAM officially classifies the standard 11-speed X-Horizon body as a medium cage length. This length is mathematically optimized for a 1x11 configuration up to a maximum 42-tooth cog.

Product Specifications & Features

• X-HORIZON Technology:
  The "straight parallelogram" body moves purely along a horizontal plane. This design entirely eliminates ghost shifting, lowers required shifting force, and handles chain bounce.
• Type 2.1 Roller Bearing Clutch:
  Uses a self-lubricating, one-way friction clutch mechanism that dramatically increases chain tension. It completely controls chain slap and prevents dropped chains without sacrificing crisp shifting.
• CAGE LOCK Design:
  A built-in push-button lockout locks the derailleur cage forward and out of the way. This leaves the chain slack so you can easily install or remove the rear wheel.
• X-SYNC Pulley Wheels:
  Features 12-tooth square/narrow-wide jockey wheels engineered to lock tightly into the inner and outer links of an 11-speed Powerchain for maximum control.
• Cable Pull Ratio:
  Operates on SRAM's specific X-ACTUATION actuation ratio, maintaining exact, sharp shifting across all 11 gears.
• Weight & Limits:
  Weighs a nimble 256 grams, features sealed cartridge bearings, and supports a maximum gear capacity of a 42T cog.