The Shimano GRX ST-RX820 is the right-hand dual control lever at the heart of Shimano's flagship 12-speed gravel groupset. Combining hydraulic disc braking with precise mechanical shifting in a single ergonomic unit, it's built for riders who demand road-level polish on mixed terrain — from gravel races to bikepacking adventures.

Highlights

• SERVO WAVE brake action: Progressive lever geometry reduces initial brake travel so pads engage the disc faster, leaving more lever stroke for confident modulation on loose or technical surfaces.
• Gravel-optimised ergonomics: Hood shape and clamp interface are contoured specifically for flared drop handlebars, reducing palm pressure during long rides in the drops.
• Anti-slip lever blade: Textured surface borrowed from Shimano's fishing-rod technology keeps fingers locked on the blade when gloves are wet or muddy.
• Reach & free-stroke adjust: Tool-free reach adjustment fits any hand size; free-stroke adjustment dials in exactly where the brake engages.
• One-way bleed port: Outboard bleed port simplifies maintenance — bleed the system without removing the lever from the bar.
• Mineral oil hydraulics: Shimano mineral oil is non-corrosive and stable across a wide temperature range, making it safer and easier to work with than DOT fluid.
• 12-speed mechanical shifting: MTB-derived shift internals deliver smooth, light single-finger gear changes front and rear with GRX-compatible derailleurs.

Gravel-Ready Design

The ST-RX820 hood geometry was engineered alongside GRX-specific flared handlebars. The outward sweep of gravel bars naturally rotates the lever to a more comfortable angle in the drops — Shimano designed the clamp interface and hood shape to match this geometry precisely, so brake and shift inputs feel natural whether you're riding on the hoods, in the drops, or reaching across the cockpit on rough terrain.

Hydraulic Performance

Mineral oil hydraulics deliver consistent, powerful braking across all conditions without the fluid degradation associated with DOT-based systems. The SERVO WAVE mechanism means less lever travel to reach full braking power, giving riders precise bite-point control even with cold or fatigued hands. The integrated bleed port makes routine maintenance straightforward without special bar-removal steps.

Compatibility & Fit

Right-hand lever (rear brake, front derailleur shift in Australian setup) for 2×12-speed GRX drivetrains. Compatible with GRX RD-RX820 rear derailleur and FD-RX820 front derailleur supporting 48/31T cranksets with 11-34T or 11-36T cassettes. Clamp band diameter: 23.8–24.2 mm (suits standard drop bar diameter). Brake caliper sold separately — compatible with BR-RX820 flat mount, BR-R9270, BR-R8170, and BR-R7170 calipers. Uses Shimano mineral oil (not DOT fluid).