Shimano GRX Spec. Di2 RD-RX825 12v Direct Mount Compatible Rear Derailleur

Shimano GRX Di2 RD-RX825 12-speed Rear Derailleur – Wireless Electronic Derailleur for Gravel and Adventure

Smooth and reliable electronic shifting for every type of terrain

The Shimano GRX Di2 RD-RX825 12-speed represents excellence in gravel bike components. Designed to tackle mixed and rough terrains, this electronic rear derailleur offers advanced wireless performance, smooth transmission management, and total customization thanks to synchronized Di2 technology.

Equipped with SHIMANO SHADOW RD+ technology, the adjustable stabilizer minimizes chain noise and prevents accidental drops even during the most aggressive pedaling. The integrated charging port simplifies powering the system, while the tensioner ON/OFF switch allows adapting the derailleur's behavior to the type of surface: ON for gravel, OFF for asphalt.

Compatible with 12-speed 11-34T and 11-36T cassettes, the GRX Di2 RD-RX825 is the ideal companion for gravel cyclists seeking precision, quietness, and technological integration.

Technical Specifications – Shimano GRX Di2 RD-RX825 12-speed

• Wireless electronic derailleur with integrated charging port

• Cassette compatibility:

  • Min. small sprocket: 11T

  • Max. large sprocket: 36T

  • Compatible with 11-34T and 11-36T cassettes

• SHIMANO SHADOW RD+ technology

  • Clutch tension adjusted for gravel use

  • Maximum chain stability on rough terrain

• Adjustable ON/OFF stabilizer

  • ON for trail and gravel

  • OFF for smooth surfaces

• Total capacity: 40T

• Multifunction LED indicator

  • Battery status

  • Adjustment mode

  • Wireless pairing

• Customizable Di2 shifting modes

  • Fully synchronized or semi-synchronized shifting, adaptable to rider preferences