12-speed Eagle drivetrains transformed mountain bike gearing, and the GX rear derailleur delivers that range without the price tag of X01 or XX1. The mechanical shifting platform uses the same 520% gear range as SRAM's top-tier options, giving you a 10-52T cassette spread that handles steep climbs and fast descents without a front derailleur.

The cage design on this derailleur uses SRAM's X-Horizon geometry, which limits lateral movement while allowing vertical travel for chain management. What that means in practice: the derailleur moves straight up and down as you shift rather than swinging in an arc, which keeps shifting consistent across the entire cassette. The Roller Bearing Clutch maintains chain tension over rough terrain, reducing chain slap against your chainstay and preventing dropped chains when you're hammering through rock gardens or root sections.

SRAM builds the GX Eagle with an aluminum cage and steel hardware where it counts. You're adding weight compared to carbon-cage X01 and XX1 derailleurs, but you're also adding durability for the inevitable contact with rocks and logs. The Lunar colorway gives you a matte gray finish that shows trail grime less than gloss black options.... Read More