Building on the X-Horizon rear derailleur design of the 1x11 drivetrains, the GX Eagle 12-Speed Rear Derailleur follows it's Eagle breathren in terms of engineering and function, making shifting effortless despite the great range of the cassette and narrow dimensions of the 12-speed system. With it's upgraded Roller Bearing Clutch and Cage Lock, controlling chain action and swapping wheels have never been more enjoyable. The precise, positive shifts of the 1:1 ratio made possible by X-Actuation from the shifter through the derailleur have never been faster, over the greatest range every seen in a cassette. Top quality materials and construction ensure incredible shifting, durability and light weight. At 290 grams this GX Eagle design delivers the precision you expect from any and all SRAM drivetrains.

The body and cage design of X-Horizon increases mechanical efficiency while resisting torsional forces that result when the unit is under serious pressure from shifting under load at extreme angles. The curves and angles reflect strength and extremely deep knowledge of how force loads must be managed. The aluminum and steel body is stout, yet sculpted strictly for what is necessary. There is no excess of material to make you feel better about the look. The new B-Bolt mount design is a great example. At first glance it looks minimal, but when you examine it closely you see how the shapes and sectioning create strength, which makes this crucial zone stiffer and stronger than its predecessor, for great durability and consistency under load and aids in quieting the system. The cage is pure X-Horizon, optimized in length and stiffness for the staunch requirements of of Eagle's 10-50 cassette despite it'relatively compact length. The offset inner plate is machined and shaped from forged aluminum to resist wear, flex and torsion as the outer plate, which works in conjunction with the inner plate via the pulley wheels to keep the cage tracking perfectly inline with the intended shift.

SRAM has designed X-Sync pulley wheels that have optimal tooth profiles for the Eagle 12-speed chain. These hyper specific pulleys carry the chain smoothly, and have been paired specifically to manage the long chain required for the full cassette range. The re-positioned upper pulley has 12 teeth and the lower has 14 teeth, allowing the cage to be a moderate length. The pulleys travel on super smooth stainless steel bearings, which are durable, cost effective and easy to maintain. Managing the cage is a newly iterated Roller Bearing Clutch. This type-3 version was developed for Eagle XX1, but carried down, as it features a smoother torque curve, which makes the system quieter and performs more consistently as the derailleur is shifted. By preventing the cage from bouncing and the chain the slapping, the clutch system improves durability and safety, while keeping the derailleur perfectly postured for your next shift. The Cage Lock Button still allows you to lock out the derailleur cage position for easier, faster wheel changes, but the location has moved rearward of the Roller Bearing Clutch pivot, which keeps it somewhat sheltered from mud and dirt coming upward as you ride forward. Smart, and effective.

With Eagle, SRAM's shifting has never been smoother faster, or more precise. Refinements at the lever start the process, and the GX Eagle 12-Speed Rear Derailleur delivers, every time. The SRAM engineering team had already created excellent systems from which to build on and improve but you have to admit, the inspiration for Eagle challenged every physical and technical requirement. Whether you are running a long travel hard tail or 6" of travel front and rear, the shifting capacity and consistent performance in any combination from the 1x ring to the 10-50 cassette is head-scratchingly awesome.