Shimano GRX Di2 FD-RX815 (Braze-On)

Digital Precision for Dirty Roads.

The FD-RX815 is a masterpiece of electronic integration. It features a +2.5mm chainline compared to traditional road front derailleurs, providing the critical tire clearance needed for high-volume 700c and 650b gravel tires. Because it is a Di2 component, it eliminates the "heavy" feeling of mechanical front shifting. With a high-torque motor and auto-trim technology, it perfectly aligns itself to prevent chain rub, allowing you to focus entirely on the trail ahead.

Why the FD-RX815 is the Ultimate Gravel Upgrade:

• Increased Tire Clearance: The +2.5mm outboard chainline is specifically designed to accommodate the wide tires (up to 45mm+) common on modern gravel frames, preventing the derailleur from interfering with your rubber.

• Instant, High-Torque Shifting: Experience effortless shifts even when pedaling uphill or through thick mud. The Di2 motor provides significantly more force than a manual cable, ensuring the chain moves precisely every time you tap the button.

• Auto-Trim Technology: The derailleur automatically adjusts its position based on the rear gear you've selected. This eliminates "chain rub" across the entire 11Speed range, providing a silent and efficient drivetrain in every gear combination.

• Synchronized Shifting Compatible: Use the E-TUBE PROJECT app to set up "Full Sync" or "Semi-Sync" shifting. The system can automatically shift the front derailleur for you as you move through the rear cassette, keeping your cadence smooth and efficient.

• Robust 17T Total Capacity: Designed to work perfectly with the 48-31T GRX cranksets, offering a massive gear range that can handle both high-speed descents and the steepest backcountry climbs.

• Weather-Sealed Reliability: Fully waterproof and designed to live in the mud. The electronic internals are sealed against the elements, ensuring consistent performance through rain, snow, and stream crossings.

Technical Specifications:

• Model: FD-RX815

• Series: GRX DI2 (11Speed)

• Action: Down-Swing

• Mounting: Braze-On (Standard)

• Total Capacity: 17T (48-31T Crank compatible)

• Weight: ~131g

• Connectivity: E-Tube SD50 port

The Alegro Perspective: In our workshop, the FD-RX815 is the hero of "modern gravel" builds. Front shifting is historically the weak point of gravel drivetrains due to mud and cable friction, but Di2 completely removes those variables. If you're building up a Brodie Romax Adventure or a Winspace G3, this derailleur is what makes the bike feel truly premium. It’s silent, it’s powerful, and once it’s set up, you’ll never have to touch it again.

Clean Clearance. Digital Accuracy. Master your Front Shifting with Shimano GRX Di2.