Shimano GRX RD-RX817 Di2 1x11-Speed Rear Derailleur

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.