The Red AXS E1 is the road-focused counterpart to SRAM's new gravel-specific Red XPLR AXS derailleur, and unlike the 13-speed XPLR unit, this one sticks with the 12-speed Flattop platform that's been the backbone of AXS road since launch. The latest SRAM RED AXS debuted in May 2024 , and this derailleur is the piece that anchors the entire electronic road ecosystem. If you're building a 1x or 2x road bike around the current Red groupset, this is the rear derailleur that came in the box.

The headline change from the previous Red eTap AXS derailleur is capacity. It covers cassette ranges from 10-28T up to 10-36T, uses larger pulleys to increase drivetrain efficiency, and an Orbit fluid damper to keep everything in place over the rough stuff — one derailleur ready for 1x or 2x, on road or off. The 36-tooth max opens up gearing for gravel builds and steep road terrain that previously required a Force XPLR or Rival XPLR derailleur to handle. One derailleur now covers the full range of AXS road cassettes, which simplifies the parts picture considerably.

The Orbit fluid damper is the key mechanical detail. Rather than a traditional clutch, it uses silicon fluid as part of the damper system, which results in lower resistance on the spring — easier shifting and less chain bounce. The damper works continuously instead of engaging at a threshold like mountain bike clutches do, so chain slap over broken pavement stays quiet without adding drag to every shift. Paired with the larger X-Sync pulleys, the drivetrain runs noticeably smoother than the previous generation.... Read More