The Shimano GRX ST-RX400 is a right-hand Dual Control Lever built for gravel and mixed-terrain riders who demand reliable hydraulic braking alongside smooth 10-speed shifting in a single ergonomic unit. Designed as part of Shimano's GRX groupset, this lever brings confident stopping power and light, precise gear changes to drop-bar gravel bikes.

Highlights

• Hydraulic disc braking: Mineral oil hydraulic system delivers consistent, modulated braking in all conditions — rain, mud, and dust included.
• Mechanical 10-speed shifting: Light, responsive shifting action controls the rear derailleur via cable — comparable in feel to higher-tier Shimano road groups.
• Gravel-tuned ergonomics: Raised hood profile and flared bracket shape reduce hand fatigue over long days in the saddle on rough terrain.
• Anti-slip brake lever: Textured lever surface keeps your grip secure when descending on wet or bumpy ground.
• Reach adjust: Tool-based reach adjustment lets you dial in the lever-to-grip distance to suit your hand size and riding preference.
• Tidy cable routing: Internal shift cable routing keeps the cockpit clean and protects cables from the elements.

GRX Gravel Performance

The GRX 400 series sits at the entry point of Shimano's dedicated gravel groupset range, offering gravel-specific geometry and ergonomics at an accessible price. The ST-RX400-R is the right-hand lever, handling rear shifting and front brake control (Australian set-up). It pairs with Shimano's GRX and Tiagra-compatible hydraulic calipers using mineral oil — the same fluid used across Shimano's road and mountain hydraulic lines for straightforward servicing.

Compatibility & Fit

The ST-RX400-R is a 10-speed right-hand lever compatible with the following Shimano rear derailleurs: RD-RX400 (GRX) and RD-4700 (Tiagra). For front shifting the left-hand lever (ST-RX400-L, sold separately) pairs with FD-RX400 or FD-4700. The hydraulic system uses mineral oil and is compatible with Shimano flat-mount hydraulic disc brake calipers including BR-RX400 and compatible Shimano road hydraulic calipers. Sold without hose or caliper.