Bring Ultegra Di2 precision to mixed terrain. The Shimano RD-RX805-GS pairs electronic accuracy with a Shadow RD+ chain stabiliser clutch, giving you quiet, reliable shifting whether you're on smooth tarmac or rough gravel. Flip the ON/OFF switch to disengage the clutch for road riding — one derailleur, every surface.

Highlights

  • Ultegra RX Di2 — electronic 11-speed shifting with gravel-ready clutch
  • Shadow RD+ clutch suppresses chain slap and improves retention on rough terrain
  • ON/OFF clutch switch for easy transition between road and off-road modes
  • Medium (GS) cage supports cassettes up to 34T
  • Total capacity: 39T — suits 2×11 drivetrains with wide-range gearing
  • Compatible with Shimano road Di2 systems including Dura-Ace and Ultegra Di2
  • 1× SD50 port for Di2 wiring integration
  • Supports Synchronized Shifting and customisation via E-TUBE Project app

Shadow RD+ Clutch Technology

Shimano's Shadow RD+ mechanism applies tension to the cage, reducing the chain movement that causes noise and dropped chains on rough ground. It's the same principle used in mountain bike derailleurs, brought to road and gravel — and on the RD-RX805-GS, it's electronically integrated with full Di2 intelligence. Toggle it off in seconds for criteriums or smooth sportives.

Di2 Electronic Shifting

The RD-RX805-GS runs on Shimano's proven Di2 platform. Shifts are executed by a precision motor, eliminating cable stretch and barrel-adjuster fuss. Pair with Shimano E-TUBE Project software to configure shift modes, Synchronized Shifting (semi-automatic front/rear coordination), and battery monitoring. Compatible with the full Shimano road Di2 ecosystem — Dura-Ace, Ultegra, and GRX Di2 components.

Compatibility & Fit

Designed for 2×11-speed Shimano road Di2 drivetrains. Accepts cassettes with a low sprocket of 28T–34T and a top sprocket of 11T–12T. Maximum front chainring difference: 16T. Mounts via standard 10×1 B-axle hanger or direct mount. Requires a Di2 junction or battery system and compatible Di2 shifters. Weight: 280 g.

Shimano provides a limited warranty on this product against defects in materials and workmanship for the period specified in the applicable regional warranty terms. For warranty support, return the item to Tune Cycles.
  • Shimano Ultegra RX Di2 — 11-speed electronic rear derailleur
  • Shadow RD+ clutch mechanism for chain stabilisation on rough terrain
  • ON/OFF clutch switch — easy toggle between road and gravel modes
  • Medium (GS) cage — supports up to 34T low sprocket
  • Total wrap capacity: 39T
  • Maximum front chainring difference: 16T
  • Compatible with Shimano road Di2 (Dura-Ace, Ultegra, GRX Di2)
  • 1× SD50 Di2 port
  • Synchronized Shifting compatible via E-TUBE Project
  • Standard 10×1 B-axle mount; Direct Mount compatible
  • Weight: 280 g
  • Colour: Black
BrandShimano
SeriesUltegra RX
Part NumberRD-RX805-GS
Speeds11-speed
Cage LengthMedium (GS)
Shift TypeElectronic Di2
Max Low Sprocket34T
Min Low Sprocket28T
Max Top Sprocket12T
Total Capacity39T
Max Front Difference16T
ClutchShadow RD+ (ON/OFF switch)
Di2 Port1× SD50
MountStandard 10×1 / Direct Mount
Weight280 g
ColourBlack
SKU SHM-IRDRX805GS
Barcode # 4524667340553
Brand Shimano
Shipping Weight 0.3000kg
Shipping Cubic 0.001000000m3
Unit Of Measure each
Must be installed and serviced by qualified bicycle mechanic

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