The Shimano GRX ST-RX820 Dual Control Lever with BR-RX820 rear hydraulic disc brake caliper brings top-tier gravel performance to mixed-terrain riders who demand crisp mechanical 12-speed shifting and confident hydraulic stopping power in a single ergonomic unit. Designed from the ground up for gravel cycling, this left-hand lever set controls your rear brake — the primary brake in Australian riding convention — pairing seamlessly with the full GRX RX820 groupset.

Highlights

• Mechanical 12-speed shifting with smooth, precise cable actuation
• SERVO Wave brake lever technology for rapid initial pad engagement and progressive power build
• 2-piston BR-RX820 flat-mount hydraulic caliper with 10% wider pad clearance to reduce disc brake noise
• Anti-slip lever surface — borrowed from Shimano's fishing-rod technology — maintains grip in wet and muddy conditions
• Adjustable reach mechanism to fit any hand size or riding style
• Ergonomic lever body shaped for flared handlebars, reducing palm pressure on long gravel efforts
• Mineral oil hydraulic system for consistent, fade-resistant braking
• Includes L05A resin brake pads with fins for improved heat dissipation
• 1700mm brake hose pre-installed for rear caliper routing

SERVO Wave Technology

Shimano's SERVO Wave action delivers fast initial pad travel so the pads contact the rotor with minimal lever movement, then multiplies braking force progressively through the rest of the stroke. The result is confident, controllable stopping whether you're scrubbing speed on loose gravel descents or managing precise trail braking.

Gravel-Optimised Ergonomics

The ST-RX820 lever body is engineered for the flared handlebars that define modern gravel cycling. Textured anti-slip surfaces on the tops and lever blade maintain purchase even when hands are coated in mud or rain. The reach-adjust mechanism lets riders dial in the exact lever distance to suit their hand size, glove thickness, and riding position without tools on the road.

BR-RX820 Hydraulic Caliper

The matched BR-RX820 2-piston flat-mount caliper features Shimano's updated bleed port design — an Allen-key bleed port replaces the older spanner fitting, making home servicing straightforward. Pad clearance is increased by 10% over the previous generation, reducing the risk of pad rub and associated brake noise on rough terrain. The caliper ships with L05A resin pads installed.

Compatibility & Fit

This is the left-hand lever set, pairing the ST-RX820-L shift/brake lever with the BR-RX820 rear hydraulic disc brake caliper and 1700mm hose. Compatible with Shimano GRX 12-speed mechanical drivetrain components including RD-RX820 (2x) and RD-RX822 (1x) rear derailleurs. Also compatible with Shimano 12-speed road mechanical rear derailleurs. Requires a flat-mount disc brake frame/fork rear mount. Hydraulic fluid: Shimano Mineral Oil. Rotor sold separately — compatible with 140mm and 160mm flat-mount rotors using appropriate adapters; note the 170mm in the part number refers to the hose length specification code, not rotor diameter. Pair with the right-hand ST-RX820-R for a complete GRX mechanical dual-control lever setup.