The Shimano GRX ST-RX610 dual control lever combines 12-speed mechanical shifting with hydraulic disc braking in a single gravel-optimised unit, bundled here with the GRX BR-RX400 front flat-mount hydraulic disc brake caliper as a J-Kit set. Designed for gravel racers and endurance riders who demand confident control across mixed terrain, the ST-RX610 delivers fingertip-light shifting and reliable stopping power in all conditions.

Highlights

• Gravel-specific ergonomics: Textured hood and anti-slip brake lever surface increase grip and control on rough, uneven terrain.
• Reach adjust mechanism: Lever-to-bar distance is adjustable to suit any hand size, riding style, or individual preference.
• 12-speed GRX shifting: Light and responsive mechanical shifting drawn from Shimano's MTB technology — crisp, single-finger front and rear gear changes.
• Hydraulic disc braking: Mineral oil hydraulic system delivers consistent, modulated braking power regardless of conditions.
• BR-RX400 2-piston caliper: GRX flat-mount front caliper with finned L03A resin pads and ICE Technologies heat management for fade-resistant braking.
• J-Kit convenience: Pre-bled hose connection system simplifies installation, maintenance, and wheel removal.
• Easy Hose Joint System: Streamlines brake hose replacement and everyday servicing.

ST-RX610 Dual Control Lever

The ST-RX610 is Shimano's 12-speed GRX hydraulic dual control lever, combining braking and shifting in a single ergonomic body designed for drop-bar gravel bikes. The lever shape is optimised for all-day comfort on flared bars and features a non-slip coating that keeps your hands secure when the trail turns technical. Reach adjustment allows the lever to be set precisely for your hand size without tools.

BR-RX400 Front Brake Caliper

The GRX BR-RX400 is a 2-piston hydraulic flat-mount disc brake caliper engineered for consistent performance on gravel and mixed-terrain courses. Shimano ICE Technologies heat dissipation technology manages braking temperatures under sustained load, while finned L03A resin pads extend pad life and reduce noise and fade. The caliper mounts directly to the fork via the Flat Mount standard, compatible with 140mm and 160mm rotors (sold separately, adapter required for 160mm).

Compatibility & Fit

This set includes the right-hand ST-RX610 lever (controls rear brake and rear derailleur — note: Australian standard is right lever = front brake; confirm your setup before ordering) and the BR-RX400 front brake caliper. Compatible with Shimano GRX 12-speed rear derailleurs (RD-RX820 for 2×12, RD-RX822 for 1×12). Brake caliper uses Flat Mount attachment; supports 140mm rotor (SS adapter) or 160mm rotor (S adapter, sold separately). Hydraulic fluid: Shimano mineral oil. Rotors and adapters sold separately.