Everything you need to run Shimano's GRX 820 mechanical 1x12 drivetrain arrives in one shipment with this Excel Sports kit. Sourcing individual GRX components has been a frustrating exercise since the 12-speed platform launched, with levers appearing in stock one week and derailleurs vanishing the next. The GRX-820 Mechanical 1x 12-Speed Kit solves that problem by bundling the shift lever, brake levers, calipers, rear derailleur, cassette, chain, and all the hydraulic hardware into a single package. You still select your own crankset, bottom bracket, and rotors based on your frame and preferences, but the core drivetrain and braking system comes ready to build.

The right-hand ST-RX820 lever handles both shifting and rear braking through Shimano's dual-control design. Mechanical cable actuation drives the 12-speed rear derailleur while the integrated hydraulic master cylinder operates the rear brake caliper. The left-hand BL-RX820 lever is brake-only, which is exactly what a 1x drivetrain needs. Both hoods feature the gravel-specific ergonomics Shimano developed for use with flared handlebars, including a raised hood profile that prevents your hands from sliding forward during rough descents and a textured anti-slip coating on the brake levers themselves. The lever throw has actually shortened compared to the 11-speed version, a side benefit of the internal mechanism changes required for the additional gear.

Cassette selection determines which rear derailleur ships with your kit. The 10-45T option pairs with the RD-RX822 GS medium-cage derailleur, while the 10-51T gets the SGS long-cage version. Both derailleurs use Shimano's Shadow RD+ architecture with an adjustable clutch mechanism that keeps chain tension consistent over rough terrain. The clutch tension has been tuned specifically for gravel conditions rather than simply borrowing mountain bike settings, and you can disengage it entirely for easier wheel removal. The derailleur cages are interchangeable between GS and SGS, so if your terrain requirements change down the road, you can swap cages rather than buying a complete new derailleur. That flexibility means you can start with the 10-45T range for racing and switch to 10-51T for bikepacking without replacing the entire mech.... Read More