Shimano GRX RD-RX820 12-Speed Rear Derailleur

Performance
Built for gravel, the GRX RD-RX820 delivers silent, secure 12-speed shifting on rough and mixed terrain. Shimano’s Shadow RD+ design with an adjustable chain stabiliser prevents chain slap and drops, and an ON/OFF stabiliser switch lets you match the setup to the terrain. The low-profile body reduces the risk of crash damage.

Options
Available in 36T, 46T and 51T maximum-sprocket versions to suit different cassette ranges – the wider-capacity options support mullet and wide-range setups. Select the version that matches your cassette.

Cassette Compatibility

36T: Top sprocket: Max. 11T/Min. 11T
Low sprocket: Max. 36T/Min. 34T

46T:Top sprocket: Max. 10T/Min. 10T
Low sprocket: Max. 45T/Min. 45T

51T:Top sprocket: Max. 10T/Min. 10T
Low sprocket: Max. 51T/Min. 51T