Semi-wireless is Shimano's answer to the two competing demands of modern Di2: cleaner cockpits and reliable shifting across long rides. The Dura-Ace ST-R9270 dual control lever transmits shift commands wirelessly to the rear derailleur via a CR1632 coin cell that lives inside each hood, while the derailleurs themselves stay wired to a central battery. You get the tidy handlebar setup that fully wireless systems are known for, without giving up the multi-thousand-kilometer battery life that comes from powering the motors off a bigger cell tucked in the seatpost or frame.

The R9200-generation ergonomics are a real departure from R9170. The hood body sits taller with a peak that gives your palm something to lean into on long climbs, and the body itself is longer for more real estate when you're riding on the tops. Both the brake lever blade and the lever body are carbon fiber, and Shimano uses titanium hardware to keep the weight down. The claimed shifter pair weight lands at 350 grams, and the reach adjust is a bolt-driven system that lets you dial the lever position to match your hand size rather than settling for a preset.

Braking comes courtesy of the included BR-R9270 flat-mount caliper, which uses Servo Wave Action to change the leverage ratio through the lever pull. Initial travel closes the pad gap quickly, then the ratio shifts to give you finer control once the pads contact the rotor. Pad clearance opened up 10% versus the previous generation, which is worth knowing if you've been chasing rotor rub on your current setup. Finned L03A resin pads are included in the box to help shed heat on long descents.... Read More