What Our Gearhead® Experts Are Saying:"This derailleur sets the bar for responsive shifts and low-maintenance racing—smooth, silent, and tough, even after hard drops or muddy rides. Battery swaps and app setup are as easy as it gets."XX1 Eagle AXS 12-Speed Rear Derailleur makes every shift count with a wireless design that responds instantly, no matter how hard you’re pedaling. The carbon cage and titanium hardware keep weight to a minimum for XC and trail rides, while more ground clearance and a subtle, forward-set design protect the mechanism against rocks and trail damage. The Overload Clutch disengages the motor if struck, then resets without fuss—adding resilience for technical terrain. Programmable through the AXS app for custom shift logic and integration with Reverb AXS dropper posts, this derailleur is truly the heart of high-performance electronic drivetrains for racers and serious riders alike.