Shimano GRX Di2 FD-RX825

Fast Electronic Shifts. Expanded Tire Clearance.

The hallmark of the Shimano GRX FD-RX825 Derailleur is its +2.5mm outboard chainline design. By pushing the front derailleur architecture further outward, Shimano creates valuable real estate between the seat tube and the rear tire. This allows riders to run wide 2x gravel tires (up to 700x45c) without sacrificing the tight, optimized gear steps of a double chainring setup. Driven by a powerful internal Di2 motor, the FD-RX825 executes precise, crisp front shifts in a fraction of a second.

Why the GRX FD-RX825 Belongs on Your 2x Gravel Build:

• Instant 2x12 Electronic Front Shifting: High-torque Di2 motor drives the chain effortlessly between chainrings with absolute precision, even when laying down heavy power on steep gradients.

• +2.5mm Outboard Gravel Chainline: Increases tire-to-derailleur clearance to accommodate wider gravel tires and prevent sticky mud buildup around the bottom bracket.

• Full & Semi-Synchronized Shift Modes: Configurable via the E-TUBE PROJECT app to automatically manage front derailleur shifts when you change gears at the rear, keeping your cadence completely fluid.

• Auto-Trimming Tech: Automatically micro-adjusts the derailleur cage position as you shift across the rear cassette, eliminating frustrating chain rub in every gear combination.

• Direct-Mount & Braze-On Compatibility: Mounts securely to standard braze-on frame tabs or band-clamp adapters for broad frame compatibility.

Technical Specifications:

• Series: Shimano GRX RX820 / RX825 Di2 Series

• Drivetrain Speed: 2x12Speed Electronic

• Chainline: 47.0mm (+2.5mm wider than standard road front derailleurs)

• Top Gear Teeth: 48T (Optimized for GRX 48/31T and 46/30T cranksets)

• Total Capacity: 17T

• Mounting Standard: Braze-On (Clamp band adapter available separately)

• System Connection: Wired E-TUBE SD300 port (connects to central internal battery)

The Alegro Perspective: In the shop, 2x gravel setups are coming back strong for riders who want tight gear jumps for endurance pacing without suffering massive cadence gaps. The FD-RX825 solves the old 2x dilemma, giving you that massive gear range while still allowing you to run plump 45c tires for rough descents. Plus, the auto-trimming feature is pure magic: you can cross-chain all day long across the 12-speed cassette without ever hearing the chain brush against the derailleur cage.

Effortless Front Shifting. Maximum Tire Clearance. Perfect Your Gravel Cadence with Shimano.