Dropping the front derailleur doesn't mean your left hand has nothing to do. The Shimano GRX Di2 1x 11-Speed Kit includes Di2 shift levers on both sides because the e-Tube system lets you program either lever to handle upshifts, downshifts, or multi-shift sequences however you prefer. Some riders set up the left lever as a dedicated downshift for faster access when terrain suddenly steepens, while others program multi-shift bursts for rapid gear changes. This is a partial kit covering braking, shifting, gearing, and the Di2 power system, so you'll still need a crankset, bottom bracket, disc rotors, SD50 e-Tube wiring, and a Junction A box to complete the build.

The ST-RX815 levers use the wired e-Tube architecture rather than the semi-wireless system found on newer Shimano road groups, which means SD50 wires run from each lever through the frame to the junction box and derailleurs. Each lever has two SD50 ports for wiring flexibility, and the Junction A box handles charging, firmware updates, and D-Fly connectivity if you add the optional wireless transmitter. The BT-DN110 battery mounts inside your seatpost and charges through the Junction A box with the included SM-BCR2 charger, delivering about 1.5 hours to full charge and enough runtime for months of typical riding.

GRX lever ergonomics differ significantly from Shimano's road components. The hoods feature raised heads that prevent your hands from sliding forward on rough terrain, plus textured surfaces on the hoods and brake levers for grip in wet or dusty conditions. The recessed finger notch keeps your hands from creeping upward during long descents. These details matter more on gravel than on smooth pavement because you spend more time on the hoods absorbing vibration and fighting for control on loose surfaces.... Read More