1x13 Rear Derailleur

Brand: Rotor

The 1x13 rear derailleur was the heart of the world's first hydraulically actuated 13-speed drivetrain, unveiled at Eurobike 2018 and released in 2019. Unlike every rival, it is driven neither by cable nor by electronics but by hydraulic fluid pushed through a 3mm hose from the lever; the shift indexing lives inside the mechanically-machined aluminium derailleur itself. A distinctive one-sided cage cantilevers the lower pulley, a clutch tensions the long 1x chain, and a switch on the mech lets it drop into the highest gear or convert to 12-speed for SRAM/Shimano/Campagnolo cassettes. A single short cage spans everything from 10-36 to 10-52. Note: no actuation enum captures hydraulic drive - it is neither electronic nor cable.