Or as low as 
Shimano GRX 810 Rear Derailleur – 11 Speed
With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience and shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features and ON/OFF switch for the chain tensioner.
Features
- Adjustable chain stabilizer prevents chain slapping and drops
- Switch stabilizer ON/OFF to match the terrain
- Gravel-tuned clutch tension
- Compatible with current road Dual levers
- Low sprocket: Max. 34T/Min. 30T
- Total capacity: 40T
- Smooth and reliable mixed surface shifting
