The Shimano GRX RD-RX820 12-Speed Rear Derailleur is built specifically for gravel riding, delivering smooth, quiet, and reliable shifting across rough and varied terrain. Designed for 1x or 2x GRX 12-speed setups, it features Shimano’s Shadow RD+ clutch system, which stabilizes the chain to reduce slap and improve chain retention on bumpy surfaces. Its low-profile design keeps it out of harm’s way, while the refined actuation ensures precise, consistent shifts even under load. Compatible with wide-range cassettes up to 36T, the GRX RD-RX820 offers the versatility and durability needed for everything from fast gravel races to long backcountry adventures.