GRX Di2 2x12 rear mech
Shimano GRX RD-RX825 Di2 Rear Derailleur
The semi-wireless GRX Di2 rear mech for 2x12 gravel builds, combining fast electronic shifting with a switchable Shadow RD+ clutch to keep the chain quiet on rough ground. It runs 11-34T and 11-36T cassettes.
Highlights
Why we rate it
Clutch you can switch
Shadow RD+ damps chain slap on rough tracks and can be turned off for smooth roads or easier wheel removal.
Wireless and rechargeable
The wireless unit and charging port are built in, so it pairs straight to the GRX Di2 levers.
Gravel-tuned tension
Clutch tension is set specifically for mixed-terrain riding rather than road use.
Status at a glance
An LED shows battery level and pairing or adjustment mode.
Tech specs
Specification
Manufacturer specification. Details may change without notice.
Specification
- Model code
- RD-RX825
- Speeds
- 12
- Actuation
- Di2 (semi-wireless, battery-in-frame)
- Drivetrain
- 2x
- Max low sprocket
- 36T
- Min low sprocket
- 34T
- Top sprocket
- 11T
- Total capacity
- 40T
- Clutch
- Shimano Shadow RD+ with on-off switch
- Chain
- Shimano HG 12-speed
- Compatible levers
- ST-RX825 (wireless)
Ordering
Available from The Cycle Collective
Available to order through The Cycle Collective in Dorking. For availability, setup or advice, call 0203 148 6764 or email hello@thecyclecollective.cc.