Precise electronic shifting and confident hydraulic braking in a single gravel-tuned package. The Shimano GRX Di2 ST-RX825 right-hand lever delivers wireless 12-speed Di2 shifting alongside smooth hydraulic disc brake actuation, while the BR-RX820 caliper brings low-noise, low-maintenance stopping power — all engineered specifically for the demands of gravel and mixed-terrain riding.

Highlights

• Wireless GRX Di2 12-speed electronic shifting — no junction wires required
• Three customisable Di2 buttons per lever via Shimano E-TUBE PROJECT Cyclist app
• Gravel-optimised hood shape integrates seamlessly with flared handlebars
• Anti-slip coating and ribbed hood texture for secure grip in all conditions
• SHIMANO FRONT SHIFT NEXT functionality for extended satellite shifter customisation
• BR-RX820 flat mount caliper with 2-piston design and 10% wider pad clearance for reduced brake noise
• ONE WAY BLEEDING system for quick, clean hydraulic maintenance
• Compatible with 140mm and 160mm rotors (bracket included)

GRX Di2 ST-RX825 Lever

The ST-RX825 is Shimano's flagship GRX gravel lever, redesigned for 12-speed wireless Di2 operation. Each lever houses two replaceable CR1632 coin cell batteries with an expected lifespan of 3.5 to 4 years — no charging required. The ergonomic hood cross-section is optimised for drop bars with a flare, keeping your hands comfortable and in control on long gravel days. Three Di2 ports allow connection to satellite shifters (sold separately), giving you full customisation of shift assignments through the E-TUBE PROJECT Cyclist app.

BR-RX820 Hydraulic Disc Brake Caliper

The BR-RX820 is a low-profile flat mount caliper built for Shimano's GRX gravel groupset. Its 2-piston design uses L05A-RF resin pads with fins for enhanced heat dissipation, and the 10% wider pad clearance compared to previous generations significantly reduces the chance of annoying brake rub and noise on rough terrain. Shimano's ONE WAY BLEEDING process — using mineral oil — streamlines hydraulic maintenance by minimising the risk of air entering the system, so servicing is faster and cleaner.

Compatibility & Fit

The ST-RX825 lever is the right-hand unit for rear brake (Australian standard) and rear electronic shifting, operating a 2x12-speed GRX Di2 drivetrain. It is compatible with Shimano's GRX Di2 derailleurs and Di2 battery systems. The BR-RX820 caliper is a front, flat mount unit supplied with a bracket for use with 140mm or 160mm centre-lock or 6-bolt rotors (assembled for 160mm). Uses Shimano mineral oil. Rotor sold separately.