Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.
Shimano Dura-Ace and Ultegra ($4,280 and $2,566)
Shimano launched its first electronic drivetrain in 2009. From ten to 11 and now 12 speeds, the Japanese company’s Di2 drivetrains have always set the bar for shift speed and precision.
This year, in a departure from its previous launches, Shimano introduced the newest versions of its second-tier Ultegra group and its premium, lighter Dura-Ace, at the same time—a boon for budget-conscious cyclists who previously had to wait longer for updated drivetrains in their price range. Both of these new 12-speed groups aren’t completely wireless, but they are wireless where it matters. Shimano ditched the E-Tube lines that connect the shift levers to the front and rear derailleurs, to declutter cockpits and reap aerodynamic gains. A pair of small, coin-size batteries power the shifters. The rechargeable battery located in the bike’s seatpost is still wired to the derailleurs and has enough juice to last approximately 600 miles between charges.
But what puts Shimano far in front is the Hyperglide+ shifting technology, previously reserved for mountain-bike groups. Ramps on the cassette and contours on the chain allow for quicker shifting, even under heavy torque. Try as we might to jam them, both were faultless even under our most hamfisted shifts during sprints.
RockShox Flight Attendant (sold with certain bikes)
RockShox isn’t the first company to use electronic controls to balance pedaling efficiency with suspension performance, but it has produced the most refined system to date. The Flight Attendant made our rides faster, more efficient, and more fun because we were able to simply focus on the trail ahead.
The system automatically switches the front and rear suspension between open, pedal, and locked-out modes, with adjustments every five milliseconds. Wireless sensors on the fork and rear shock record information on acceleration, impacts, rider inputs, and the orientation of the bike. The sensors then relay that data to the control unit built into the fork, which adjusts the suspension. The engineers even went a step further by adding a third sensor on the crank spindle to measure cadence for uphill efficiency. Riders can fine-tune the system to spend more time in open or pedal modes, depending on preference. The Flight Attendant is designed to complement aggressive trail and enduro bikes by making them more efficient without sacrificing suspension performance on rowdy terrain. Surprisingly, it offered more support in corners than similar analog models and so helped us carry more speed.