Shimano GRX RD-RX400 10Speed

Gravel-Tuned Stability. Silent Precision.

The Shimano GRX RD-RX400 is a 10Speed mechanical derailleur that features an integrated chain stabilizer, better known as a clutch. By toggling the Shadow RD+ switch, you can engage a friction-clutch mechanism that virtually eliminates chain slap and dropped chains on rough terrain. When you're back on smooth pavement, simply flip the switch to "OFF" for a lighter shifting feel and effortless wheel removals.

Why the RX400 is a Gravel Game-Changer:

• Integrated Chain Stabilizer (Clutch): The adjustable Shadow RD+ clutch provides a quieter ride and vastly improves chain retention, allowing you to focus on the trail instead of your drivetrain.

• Shadow RD Profile: Features a low-profile design that sits closer to the frame, significantly reducing the risk of the derailleur catching on rocks, branches, or trail debris.

• Wide-Range Gearing: Designed specifically for 2x10Speed setups, it comfortably clears a 36T low sprocket, giving you the climbing gears needed for steep, loose fire roads.

• Modern Shifting Ratio: Utilizes the same refined cable pull ratio as the Tiagra 4700 and Shimano 11Speed road groups, providing a crisper, more reliable shift than older 10Speed systems.

• Gravel-Specific Tension: The internal spring and clutch tension are specifically tuned for the high-frequency vibrations of gravel riding, ensuring the derailleur stays in place even on washboard descents.

• Silent Performance: Between the clutch and the optimized pulley cage, the RX400 provides one of the quietest 10Speed riding experiences on the market.

Technical Specifications:

• Speeds: 10Speed

• Max Low Sprocket: 36T

• Min Low Sprocket: 32T

• Max Front Difference: 16T

• Total Capacity: 41T

• Compatibility: Shimano GRX ST-RX400, Tiagra 4700 series shifters

• Weight: Approx. 303g

The Alegro Perspective: In the shop, we call the RX400 the "Tiagra of the dirt". That’s a huge compliment. It brings the legendary reliability of Shimano’s mid-tier road groups to a package that can actually handle singletrack. If you are upgrading an older 10Speed gravel bike or building a budget "all-road" machine, the clutch on this derailleur is the single best performance upgrade you can make for under $100.

Clutch-Driven Security. Low-Profile Design. Gravel-Ready with Shimano GRX.