SRAM XX1 Eagle 12-Speed Rear Derailleur Review

We’ve all been there, grinding slowly up a never-ending climb as our cadence slows to a high-torque, barely moving crawl, fruitlessly clicking the shift lever in hopes that an ethereal body will drop out of the sky and deliver an extra cog to lighten the pressure. Airborne deities notwithstanding, SRAM swoops in with its Eagle one-by 12-speed drivetrain. Eagle’s gear range rivals that of a two-by system without the extra weight and worry of a finicky front derailleur. The SRAM XX1 Eagle 12-Speed Rear Derailleur brings the system together, driving precise gear changes across the entire cassette with a titanium spring and carbon fiber outer cage. Similar to SRAM’s one-by 11-speed offerings, this little derailleur holds a heap of technology bent on creating a pleasant riding experience with clean shifts and no unnecessary noise distracting from the outdoor ambiance. The Roller Bearing Clutch, long revered for its nearly unbeatable chain stabilization, gets an update with a repositioned upper pulley and larger lower pulley to accommodate the extra chain length needed to run such a wide range of cogs. Paired with a strengthened clutch, it efficiently manages chain tension to eliminate derailleur bounce and chain slap for a solid, noise-free ride. X-Horizon further boosts this stability by limiting movement across the horizontal axis, with its large upper pulley design maintaining a constant chain gap across the cassette. This effectively reduces shift initiation force and eliminates pesky ghost shifting, so you’ll drop into the right gear with minimal effort the second you want it. Last, but by far not the least, is SRAM’s Exact Actuation technology. Exact Actuation addresses the issue of different gears requiring different amounts of cable pull to shift, which in turn leads to loud cassettes and inefficient shifting. With Exact Actuation, each gear shift requires the same amount of cable pull, resulting in a predictable click and shift no matter where the chain sit…