The Shimano GRX Di2 FD-RX815-F brings electronically precise front shifting to gravel riding. Engineered specifically for the demands of off-road and mixed-terrain cycling, it delivers smooth, lag-free 2x11-speed shifts even under hard pedalling load — so you can change rings on steep climbs without backing off.

Highlights

• Electronic Di2 actuation: instant, precise front shifts at the touch of a button — no cable tension to manage or trim.
• Gravel-offset chainline: 2.5mm wider chainline than a conventional road front derailleur improves tyre and mud clearance on gravel frames.
• Programmed trim positions: automatic chain guide trim eliminates chain rub without any manual adjustment.
• Synchronized Shift support: compatible with full and semi Synchronized Shift modes via the GRX Di2 junction unit, for automated front/rear co-ordination.
• 17T total capacity: wide front range suits the typical 2x gravel chainring combinations (e.g. 46/30T).
• SD50 Di2 port: single wired connection integrates cleanly into any GRX Di2 or compatible road Di2 wiring harness.

GRX Di2 Gravel Technology

GRX (Gravel Experience) is Shimano's dedicated gravel groupset platform. The FD-RX815-F is the electronic front derailleur in the top-tier RX815 Di2 tier, sharing the platform with the RD-RX815 rear derailleur and ST-RX815 Di2 brake/shift levers. The wider-than-road chainline is designed to work with GRX cranksets and gravel frame geometries, providing extra clearance that makes a real difference when the trail gets muddy.

Compatibility & Fit

Fits braze-on front derailleur mounts. Chainline: 46mm. Designed for 2x11-speed GRX Di2 drivetrains; compatible with GRX Di2 and road Di2 rear derailleurs and shifters. Recommended top chainring range: 46–48T; maximum chainring: 50T. Total capacity: 17T. Requires Shimano Di2 SD50 wiring. Not compatible with mechanical (non-Di2) shifters.