Dérailleur arrière Shimano GRX DI2 RD-RX825

Shimano rear derailleur for the named series — the chain-routing mechanism that sets precision, speed-count compatibility, and (on GRX / MTB models) chain-retention over rough ground. Matched-series pairing with shifters, cassette and chain is what delivers the in-spec shift-feel Shimano is known for. GRX is Shimano's gravel / adventure groupset — clutch-equipped derailleurs, wider-range gearing, ergonomics tuned for on / off-road riding and hood-level grip on rough surfaces. This is the Shimano GRX DI2 RD-RX825 Rear Derailleur.