In the never ending conundrum of one-by gearing choices, we've spent many a day opting for ten-tooth speed only to end up grinding over merciless grades and wishing that an extra climbing gear could somehow fly out of the sky and save us in our time of knee-breaking need. With a massive gear range across 12 cogs, SRAM's Eagle drivetrain swoops in to save the day and provide nearly the range of a two-by system in a simple one-by setup. The SRAM X01 Eagle 12-Speed Rear Derailleur ties the system together, driving precise gear changes across the entire cassette with a titanium spring and durable, forged aluminum body.
Similar to SRAM's 11-speed offerings, this little derailleur borrows a boatload of technology from its flagship XX1 sibling to create a budget-friendly, clean-shifting ride experience. 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.
The X-Horizon feature further boosts this stability by limiting the derailleur's shifting 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 addresses the issue of different gears requiring different amounts of cable pull to shift, which 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 sits in the cassette. This also means an overall quieter, better adjusted drivetrain for predictable shifting in any situation.
Shredding trails inevitably involves a mechanical or three, and the X01 Eagle 12-Speed Rear Derailleur makes the ensuing wheel swaps and maintenance easier with an update to SRAM's Cage Lock functionality that sees the lock pin tucked a bit more out of the way for additional protection from impact. Its overall functionality remains the same—just push the derailleur forward and it locks into place for quick and easy rear wheel removal or installation to get back out on the course in a snap.
- RSRAM's Eagle derailleur redefines one-by shifting
- Updated pulley design accommodates extra chain length
- Exact Actuation guides precise shifts
- Roller Bearing Clutch quiets the chain
- Locking mechanism for easier wheel removal