The Shimano GRX RX820 12-speed rear derailleur is designed for gravel use with 2x drivetrains and a wide-range road bike cassette. It has quiet, reliable shifting and excellent chain security. RD-RX820 is compatible with 34 and 36 teeth on the largest cassette sprocket. It also features Shadow Plus technology, an integrated chain stabiliser, which prevents the chain from slapping on rough surfaces and thus counteracts chain drop. The function can also be switched off when you are riding on smoother roads or when you want to remove the wheel.
Mechanical rear derailleur for gravel bikes with 2x12-speed setup
Safe and quiet shifting on mixed surfaces
Smooth and reliable gear changes
Adjustable chain stabilisation prevents chain drop
Stabiliser with on/off switch to adapt to the terrain and for easy wheel removal