Shimano GRX FD-RX815 Di2 Front Derailleur – 11-Speed, Down Swing, Braze-On

The Shimano GRX FD-RX815 Di2 Front Derailleur is purpose-built for gravel and adventure cycling, delivering smooth, reliable electronic shifting across mixed terrain. Designed for 2x GRX Di2 drivetrains, this front derailleur features a down-swing, braze-on design with optimized geometry for wider tire clearance. Engineered to accommodate chainstay angles of 61–66° and top gears of 46–50T, it ensures precise, consistent shifts for 11-speed drivetrains in rugged conditions.

Why you’ll like it

• GRX-specific design – engineered for gravel and adventure performance.
• Di2 electronic shifting – delivers precise, reliable shifts at the push of a button.
• Braze-on mount – lightweight and clean installation.
• Down-swing configuration – optimized for frame compatibility and wide tire clearance.
• Supports 46–50T top gear – ideal for gravel and endurance gearing setups.
• Chainline: 46 mm – designed to match GRX 2x drivetrains.

What’s in the box

• 1 × Shimano GRX FD-RX815 Di2 Front Derailleur (braze-on, down swing)

Tech specs

Manufacturer	Shimano
Series	GRX
Model	FD-RX815
Manufacturer Part #	KFDRX815F
Speed	11-speed (front)
Mount Type	Braze-on
Configuration	Down swing
Chainstay Angle	61–66°
Top Gear Capacity	46–50T
Chainline	46 mm
Application	Gravel / Adventure / Endurance road (Di2 electronic)

Fit notes

• Designed for Shimano GRX Di2 2x 11-speed drivetrains.
• Requires Di2 wiring and shifters (sold separately).
• Braze-on mount; an adapter may be required for clamp-style frames.
• Compatible with top gear chainrings between 46–50T.