The Wired Bike
As Shimano unveils its second-generation Dura-Ace Di2 groupo, it’s a good time to ask: Is electronic shifting an essential upgrade or a gratuitous and overpriced accessory?
Outside's long reads email newsletter features our strongest writing, most ambitious reporting, and award-winning storytelling about the outdoors. Sign up today.
Let’s start with a little disclosure: I am a dyed-in-the-merino Luddite cyclist. I have access to some of the finest carbon fiber road bikes and can tell you all the benefits of deep-dish carbon tubular wheels, but I still ride an inexpensive metal frame with low-profile aluminum clinchers. So when it comes to electronic shifting, which hit the market a few years ago, I’ve been skeptical, mostly because first generation Di2 was bulkier and heavier than comparable mechanical parts, and yet sported a roughly 30 percent higher price tag. I’ve also been dubious of the need for electronics.
This week at a media event in San Diego, Shimano officially unveiled the second generation of its top-shelf electronic components, Dura-Ace Di2 9070. And while I’m still on the fence about its necessity (at least for the average user), I am increasingly won over by its advantages.
The new 9070 groupo boasts a number of improvements over the first-generation 7970 component set that it replaces. Both the front and rear derailleurs are slightly smaller, lighter, and less clunky looking than the originals, and when combined with the new optional internal battery (built to fit in the seatpost, seat tube, or down tube), the electronic is lighter than mechanical for the first time ever. The difference is a negligible 24 grams, but given the pricing premium, it’s important that Shimano finally equalized the two. The Dual Control brake/shift levers are even trimmer and sport better button ergonomics than before, too.
However, the most meaningful upgrades to 9070 aren’t immediately obvious. Whereas the last iteration was a closed system, meaning you purchased a pre-wired and pre-set network, 9070 is an open system that’s upgradable, programmable, and expandable. The modular E-Tube cabling is built around plug-and-play ports (think of them like USB ports on a computer) with three on each shifter and a junction box beneath the stem for either three or five more connections. The ports serve as one means of charging the battery as well as an interface to your personal computer—you literally plug in your bike to program settings and upgrade software. This means that improvements can now be made retroactively via firmware updates so you’re not stuck with an outdated groupo as soon as you buy.
The other significance of the ports is that they allow for the addition of a slew of new peripherals: sprinter shifters (two small levers that can be placed in the drops for controlling the rear derailleur); a climbing shifter (a two-button device for the top of the bars); dual-control TT shifters (integrated brakes and shifters for base bar set-ups); and single-button TT shifters (to control the rear derailleur from the ends of TT extensions). These add-ons make it possible to shift from just about any position on the bike, hence no wasted energy moving from the drops or aerobars to the hoods just to change gears. Also, since the system is fully programmable, you can customize any button (including the ones on the hood shifters) to do anything you want, for instance your left hood could control the rear derailleur, your right hood could take care of upshifting the front and rear derailleur, etc. All changes are made from your personal computer via drop-down menus in the user interface when you plug in your bike. Finally, Shimano has added multi-shift for the rear derailleur (a function already present on Campagnolo EPS), so if you hold down a rear shift button, the derailleur drops or adds gears until you release it.
That’s a ton of options, especially for a technophobe like me, but over two days of test riding outside of San Diego I was surprised just how useful and intuitive the new functions are. My test bike, a Cervélo RCA, was equipped with the sprinter shifters, and I found myself riding in the drops much longer than usual because I could feather gears up and down without changing body position. I didn’t have a climbing shifter, but on the long haul up Palomar I watched enviously as those who did switched gearing without breaking cadence. And though I’m unconvinced of the practicality of the multi-shift function, it is pretty cool to just hold down the button while you pedal until the gear feels right.
It’s worth noting that 9070’s shifting speed and accuracy is no different than in the previous release, which is good thing because it is inarguably the best out there. The derailleurs drop and add gears immediately and perfectly every single time. Most importantly, you can shift under full load—there’s no need to ease off climbing or sprinting hard when you change to a bigger or smaller ring like you do on a mechanical setup. In both its Dura-Ace and Ultegra iterations, Di2 is the smoothest, most efficient drivetrain option I’ve tried on a bike, rivaled only by Campagnolo EPS.
Apart from electronics, Dura-Ace Di2 9070 shares crank, bottom bracket, chain, and brake calipers with the mechanical Dura-Ace 9000 group, and the performance on all of these items is up to snuff. In particular, braking is much improved over past generations, with so much power and modulation that it’s easy to overreact until you get the feeling for them. In fact, the 9000 group is one of my only reservations about the new Dura-Ace Di2. The shifting and braking performance on the mechanical group is so good that it’s hard to argue against it. But it’s safe to say that if 9000 is excellent, Di2 9070 is even better—though it isn’t perfect. For instance, I found the climbing shifter a bit unrefined-looking. More importantly, the E-Tube Project software only runs on PCs, so Mac users are out of luck without a converter like Parallels.
That brings the question back around to cost and necessity. At $4,125, Di2 9070 is extremely expensive (though still significantly cheaper than Campy Record EPS), and realistically it will run you even more than that because the peripherals like the sprinter and climbing shifters are sold separately. The mechanical 9000 group is $2,700, Ultegra Di2 6770 is $2,435, Ultegra mechanical is $1,625, and prices plummet from there. The truth is, Di2 9070 is the finest performance money can buy, and those who demand the ultimate edge (like professional racers) really have no choice. For the average consumer, the differences are real but perhaps less important, so it simply comes down to how much you’re willing to spend. The good news is that even if you can’t justify the best, performance gains like the improved braking of both Dura-Ace groups should continue to trickle into the less expensive parts.
One last note: Though I’ve been resistant to electronic drivetrains, as I continue to see their refinement and new benefits, I’m increasingly convinced that they are the future. As with all electronics, the products are sure to continue to rapidly evolve and improve and the prices will drop. (Just look at Ultegra Di2 and Shimano’s Alfine Electric for proof of that.) It’s unlikely that traditional components will ever completely go away, but I can see a day in the not-too-distant future when electronic overtakes mechanical in the same way that digital cameras have come to rule the market. When was the last time you had a roll of film developed, after all?