Rear Disc Brake Caliper Shimano GRX BR-RX400 Flat Mount

Rear Disc Brake Caliper Shimano GRX BR-RX400 Flat Mount

The Shimano GRX BR-RX400 is a hydraulic 2-piston rear disc brake caliper with Flat Mount design, developed for gravel, road and cyclocross bikes. It delivers reliable braking power and confident control on both paved and loose surfaces.

Based on Shimano’s road Flat Mount platform, the GRX caliper is optimized for gravel riding demands. ICE TECHNOLOGIES heat management with finned brake pads ensures excellent heat dissipation and consistent braking performance on long descents. Shimano’s One-Way Bleeding system makes maintenance simple and clean.

Supplied with L03A resin brake pads with fins, it minimizes heat buildup and brake noise. The aluminium caliper weighs approximately 143 g and allows quick wheel changes and straightforward setup – ideal for versatile riding from asphalt to gravel.

• Application: Gravel / Road / Cyclocross
• Group: GRX
• Model: BR-RX400-R
• Brake type: Hydraulic disc brake
• Mount: Rear
• Brake mount: Flat Mount
• Brake pads: L03A Resin with fins
• Hose connection: Straight
• One-way bleeding: Yes
• Brake fluid: Shimano mineral oil
• Recommended lever: ST-RX400
• Recommended hose: SM-BH90-JK-SSR
• Recommended rotor: SM-RT64
• Material: Aluminum
• Weight: approx. 143 g