Shimano GRX RX820 Disc Brake Caliper Rear

The Shimano GRX RX820 Disc Brake Caliper Rear is the hydraulic stopping power at the heart of Shimano's flagship gravel groupset — refined for the kind of mixed-terrain riding where brake modulation matters as much as outright power. Compared to its predecessor, the RX820 caliper is designed to deliver a more immediate initial bite point alongside improved feel throughout the braking range, giving you more precise control when the road turns loose or the gradient steepens.

Shimano engineered the RX820 with 10% wider pad clearance than the previous generation, which reduces rotor contact and drag while also quieting the caliper on rough surfaces. The housing is more compact, making wheel removal and trail-side maintenance more straightforward. A one-way bleeding process simplifies hydraulic servicing — less time bleeding, more time riding.

Shimano GRX RX820 Disc Brake Specs at a Glance

• Groupset: Shimano GRX RX820 (12-speed)
• Type: Hydraulic disc brake caliper — rear
• Pad clearance: 10% wider than previous generation for reduced noise and drag
• Bleeding: One-way hydraulic bleeding system
• Colour: Black