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. The RD-RX817 DI2 version offers the digital precision of SHIMANO electronic shifting and synchronized shifting. and is compatible with mtb cassettes with a 42T low sprocket max.

• Silent and uninterrupted rear shifting on rough terrain
• Adjustable chain stabilizer prevents chain slapping and drops
• SHIMANO SHADOW RD+
• Smooth and reliable mixed surface shifting
• Switch stabilizer ON/OFF to match the terrain
• Gravel-tuned clutch tension
• Compatible with current road DUAL CONTROL LEVER
• Top sprocket: Max. 11T/Min. 11T
• Low sprocket: Max. 42T/Min. 40T
• Total capacity: 31T