SHIMANO GRX BR-RX400 Hydraulic Disc Brake Front Flat Mount

The SHIMANO GRX BR-RX400 Hydraulic Disc Brake Front Caliper is built for riders who want dependable braking performance on gravel roads, mixed terrain, and long adventure rides. Designed as part of Shimano's GRX gravel-specific lineup, this hydraulic disc brake delivers consistent stopping power with smooth control in varying riding conditions. Whether you are riding on rough surfaces, loose gravel, or challenging road sections, the BR-RX400 provides reliable braking confidence. Its flat mount design creates a clean and compact installation while maintaining excellent frame compatibility. The brake system also features effective heat management and an easy bleeding process for simplified maintenance. With simple wheel replacement and convenient tool access, this front brake caliper offers a practical and rider-friendly setup that helps improve riding performance and overall confidence on every ride.

Key Features

• Brake Type: Hydraulic disc brake

• Position: Front brake caliper

• Series: Shimano GRX

• Mount Type: Flat mount

• Heat Management: Excellent heat dissipation for consistent braking

• Maintenance: Easy and clean bleeding system

• Wheel Service: Simple wheel replacement design

• Compatibility: Supports multiple brake pad options

• Performance: Smooth modulation and dependable stopping power

• Terrain Support: Suitable for gravel, rough roads, and mixed riding conditions

Product Specifications

• Model: BR-RX400

• Brand: Shimano

• Series: GRX

• Brake Position: Front

• Mount Type: Flat Mount

• Rotor Compatibility: 140mm / 160mm

• Factory Assembly: Assembled for 160mm rotor

• Brake Hose Compatibility: SM-BH90-JK-SSR, SM-BH90-J-SSR

• Included Brake Pads: K03S Resin Pad

• Compatible Brake Pads: K04S, L03A

• Recommended Brake Lever: ST-RX400

• Recommended Brake Rotor: SM-RT64

• Brake Fluid: Shimano Mineral Oil

• Packaging: Individual Pack

Braking Performance & Heat Control

The Shimano GRX BR-RX400 is designed to maintain stable braking performance even during long descents and demanding riding conditions. Efficient heat dissipation helps reduce brake fade while ensuring consistent control. This allows riders to maintain confidence and smooth braking feel during extended gravel rides and challenging terrain sections.

Easy Operation / Usage

• Install using a compatible flat mount frame or fork

• Pair with Shimano ST-RX400 brake lever for ideal performance

• Use Shimano mineral oil during maintenance

• Match with compatible Shimano rotors and brake hoses

• Replace brake pads easily when needed

Why Choose This Product

• Built specifically for gravel and adventure riding

• Delivers powerful and controlled braking performance

• Easy setup and maintenance process

• Reliable heat management for long rides

• Clean and compact flat mount design

• Trusted Shimano GRX quality and durability

In the Box

• 1 x Shimano GRX BR-RX400 Front Hydraulic Disc Brake Caliper