Outside the pro ranks though, the prohibitive high cost has meant it's a groupset for the elite or deep of pocket. But we think the Ultegra Di2 incarnation (aka Ultegra 6770) may change the world of electronic shifting, as it’ll be cheaper than mechanical Dura Ace.
Riding Ultegra Di2: So close to Dura-Ace
Enjoying the Swiss Alps
We spent three days riding Ultegra in the Swiss Alps, with weather ranging from hot and sunny to heavy rain.
The simple answer to how it rides is that it’s pretty much indistinguishable from Dura-Ace. If there’s any difference it may have a little less oomph when shifting under load, but you have to be really looking for it. If you’ve never experienced electronic shifting before then the ergonomics of two buttons in place of a swinging set of levers takes a little while in getting used to. But the excellent hood shape and textured button surfaces make it very easy to adapt. Compared to standard mechanical shifting, the advantage of consistent shifting is hard to underestimate. Combine that with the front mech's self-trimming function, which even allows for the worst chain line (53/28 anyone?) without fuss or drama is quite brilliant.
The question of making the switch from mechanical to electronic still exists. It was easier to dismiss with Dura-Ace Di2 - the much higher cost for small gains being the main issue, especially when shifting gears on a mechanical set-up isn’t exactly a chore, and making sure you’ve kept up on charging the battery is arguably less fuss than fettling and maintaining cables.
Rest assured the electronic set-up is just much, much easier to maintain. You don’t have to break out any tools just push the +/- buttons on the control unit should you require any adjustment. In three days riding on a brand new set-up I had to adjust the rear mech 1 step (0.3mm) to trim out a tiny amount of chain buzz in the 11-tooth sprocket.
With the advent of Ultegra, our cost concerns with electronic shifting just aren't as prominent, to the point where the benefits outweigh the downsides. That combined with rumours of a substantial number of 2012 bikes having an Ultegra Di2 option means we could be seeing the start of a revolution in road bike gearing. If Shimano does their usual trickle-down tech trick and we see a 105 level Di2 system in the coming years, we might just be witnessing the next big thing in the evolution of the bicycle drive train.
The components
The STI unit
The new STI shifting units weighed in at 313g a pair, that’s 58g more than their Dura-Ace counterparts. Most of that weight gain is because Ultegra lacks the titanium clamps.
It’s the same story with both the front and rear mechs too, with the front being 165g (41g more than DA), while the rear mech weighs in at 45g more. The reason here apart from the DA’s lighter hardware is the difference in the motors driving the system. Whilst Dura-Ace’s motors are bespoke to Shimano’s design, Ultegra has co-opted existing motors from other applications. They add weight but this vastly reduces the manufacturing cost.
The rear mech retains the same crash protection function of Dura-Ace, so that in the event of a fall the motor dislocates from the mechanism, protecting it from damage should things go wrong. It’s also good to see the Ultegra’s rear mech allow for up to a 28t cog, a much more sensible gear for the average rider. The front mech retains the brilliant auto-trim function we’ve loved about Dura-Ace Di2.
The battery is the same li-ion unit as found on DA, conservatively estimated to run for 1000km on a single charge. Recharge time is 90 minutes and the battery is guaranteed for 500 cycles, the same as quoted for Dura Ace.
For the non-powered components Ultegra 6770 (Shimano’s code for Ultegra Di2) follow the same as standard Ultegra with chainset options of 52/39, 53/39, and 50/34 and arm lengths of 165,170,172.5 and 175mm. Weight-wise its 790g including the bottom bracket (788g for the compact 50/34). Shimano cassette choice is from 11-23,12-23,11-25,11-28 and this all combines with Shimano’s latest directional chain.
The inline control unit
The inline control unit offers on-the-bike gear adjustment. In the maintenance mode and there are +/- 15 steps of adjustment of the rear mech (with each step offering 0.3mm of movement). The biggest difference between the two though is the wiring. While Dura-Ace has a four-core wiring loom, Ultegra has gone to a two core; this is 3.7mm thinner than DA, allowing for much smaller connectors. The connectors are also waterproof, meaning than unlike DA there is no need for heat-shrink connection covers, making Ultegra much easier to fit for the average home mechanic.
On dedicated frames this means smaller wiring holes but more interestingly an external cabling set is also available, making retro fitting onto non-Di2 bikes easily achievable.
The use of this new wiring loom means that Ultegra and Dura-Ace are non-compatible - for the electronics at least. That does leave it open to up spec the non-electronic components for all the benefits at a lesser cost. The other factor of the Ultegra Di2’s wiring is that due to the smaller diameter two core wire and reduced connector size it actually weighs in at 82g, that’s 36g lighter than the DA set-up. Like Dura-Ace, Ultegra will also be getting an optional satellite shifter for TT and triathlon riders.
Finally, slipping out alongside Ultegra Di2 is a new composite Ultegra-level pedal. Carbon bodied with cutaway details to reduce the total weight to 268g, compared to the standard alloy's 314g.
Charging on…
Wanting to know how much charge you've got left is simply a case of holding a shift button for two seconds, the indicator LEDs on the control unit show green for 100%, flashing green at 50%, and red at 25%, and flashing red means you really need to charge it.
An optional maintenance and diagnostic tool is also available. At a cost estimated at ~£170 this control box allows the user (or shop) to diagnose any problems, update the firmware or even customise the button functions. This isn’t needed for initial installing/fitting so it’s good to see this is a true optional extra and not a hidden cost.
Try before you buy
As part of Ultegra Di2’s launch, Shimano have made available 1000 demo bikes Europe wide. That means if you want to give it a try, your larger local Shimano dealer should have a demo bike available.
