James Huang departs the Tour de France for the official Dura-Ace 7900 launch in the lush green hills of Ebnisee, Germany to gather some first impressions (and some impromptu interval training).
All in the palm of our hands
Of all the updates unveiled for Dura-Ace 7900, we’ve held the highest hopes for the changes to the new STI Dual Control levers. Now that we’ve logged some actual saddle time, we can confirm that the revised shape is everything it’s cracked up to be, at least in terms of ergonomics.
The body’s markedly increased girth overall and flatter top yield a far more comfortable perch than 7800’s overly concave shape and the knob at the top of the lever still offers a good place to set your palms when you’re trying to go aero even without the benefit of the old version’s exposed cable housing to hook your thumbs around.
The carbon lever blade’s outward cant is a more natural fit, too, and the long-awaited reach adjustment proved rather handy on the PRO anatomic-bend bar we used during this initial testing. Even before bringing the levers closer to the bar, though, the new shifter’s larger paddles down below offers bigger targets that are easier to find when you’re in the drops and going hard.
Rear shifts actually feel identical to 7800 with the usual incredibly light and smooth action we’ve become accustomed to from Shimano. Considering the concealed derailleur housing’s slightly more convoluted gear cable routing, this should be probably be viewed as an improvement.
Even so, we had hoped for a little more here. Shimano claims a 20 percent shorter throw for the main right-hand lever but if that’s the case, it’s hardly noticeable. As compared to Campagnolo and SRAM’s newest Red group, Dura-Ace 7900’s lever throws seem far longer, especially for upshifts. The XTR group’s more advanced Instant Release and Multi-Release functions have been skipped over here in the name of weight saving, too, which means you can still only upshift one gear at a time (Red obviously has the same limitation but its far shorter throw still makes for faster multiple upshifts). In a distinct step backwards, you can now only downshift two gears at a time, not three as with 7800.
One undeniable star of the group is the new crankset.
Front shift performance is simply stunning, however, and is without doubt one of the highlights of Dura-Ace 7900. The lever action is lighter and crisper thanks to the revised cable pull ratio, and the new hollow outer chainring’s stiffer construction and updated ramp profiling yield very real dividends in terms of shift quality, particularly when you’re hard on the gas. As promised, we never experienced any chain rub in the big-big combination thanks to the slighter wider front derailleur cage and didn’t miss that outer trim position one bit.
The new chain seems to help here, too, with its differentially-profiled side plates. The inner and outer sides are now completely distinct (mechanics: take care during installation) and Shimano says the shaping improves shift quality by optimizing the interaction with the unique front and rear chain pick-up points. Again, we didn’t notice it much out back (although seriously, how much smoother could it be?) but this seems to hold true up front.
Improvements in drivetrain smoothness and longevity
The 7900 crankset is supposedly about 20 percent stiffer than the old 7800 benchmark yet a modest 15g lighter. The spider is far deeper to match up with the new hollow outer chainring and of course, the arms are still hollow-forged.
Not much has changed to the rear cassette although more aggressive machining and the addition of a fourth titanium cog (last year there were only three) mean slightly lighter weight. There’s a broadly expanded size range which means more usable gearing for more casual cyclists.
The new brakes are another standout performer on 7900. Shimano only claims a modest eight per cent improvement in dry braking power (and 100 percent in wet) but the increased control and modulation afforded by the stiffer caliper arms make it feel like much more on the road.
Braking performance on Dura-Ace 7900 is stunning with superb power and modulation matched with outstanding lever feel.
Lever action is markedly improved thanks to the revised cable pull geometry while the new pivot location (it’s now slightly closer to the bar) feels more natural in your hands and is easier to grab while on the hoods. Moving the shift mechanism further back into the lever body and disconnecting it from the brake lever also yields a lighter and snappier feel as there’s less mass to move around.
Not to be overlooked are the revised barrel adjusters which sit noticeably lower than before. While this doesn’t sound all that significant on paper, it provides very real improvements in cable routing, especially on more aggressively sloped frames or shorter/lower stems.
FlightDeck comes of age
Shimano’s integrated FlightDeck computer has always struck us as an intriguing concept but also one that fell short in execution for one reason or another. Although we didn’t get to try the new version in
The new FlightDeck will be far easier to install than previous iterations; just remove the stock cap, plug in the new units and off you go.
The new setup will be truly wireless with coded 2.4GHz transmission, unlike the current ‘wireless’ model that still has cables running from the shifter bodies to the computer head. Installation will be hugely improved as well, and not just because you no longer have to pull back the handlebar tape. FlightDeck users will now simply have to pull back the front of the shifter hood on either side, remove the top ‘knob’ of the shifter, then install the FlightDeck module in its place. Slap on the front wheel sensor, magnet and computer head and off you go. This also means that the buttons also get moved from the inner sides to the shifter peak.
There’ll be added functionality too including an integrated heart rate monitor, altimeter and calorie estimator.
Shimano readily admitted that it had a power meter and GPS system currently in development. We’re not sure how it would integrate GPS functionality into the presumably small-sized screen but no matter; the thought of a Shimano-engineered power meter has got our minds racing and we can’t wait to see what becomes of this. Stay tuned.
Concerns and compatibility
Other than what we already mentioned, a few other details gave us pause during our brief interlude with this new Dura-Ace 7900 group and nearly all of them have to do with the STI Dual Control levers. 7900 internals are noticeably exposed with no protective covers whatsoever in key areas. One good digger into the mud will likely be all it takes to jam these up right quick.
Fit and finish on the new levers is a bit disappointing too - the STI lever hoods fit inexplicably poorly (it’s somewhat lumpy) and shortening the brake lever reach leaves an unsightly gap up top. These oversights strike us as very distinctly un-Shimanolike.
On the bright side, we’re happy to report that earlier accounts of a revised rear derailleur cable pull ratio were incorrect, meaning that the new levers are compatible with older 10-speed rear derailleurs and vice-versa. However, that is small consolation as little else will be.
The new front derailleur cable pull ratio means that mismatching new and old shifters and front derailleurs will reportedly result in sluggish shifting. Also, the new levers pull more brake cable (the matching 7900 calipers are adjusted to compensate). As such, using new levers with old brakes will yield a firm lever feel but less power while old levers and new brakes will have plenty of power but a spongy feel. At least Shimano maintained the current 10-speed cog spacing.
So what do we think so far?
In spite of a few apparent missteps, Dura-Ace 7900 is still an improvement over 7800 overall and there are obvious standouts to us that will justify the upgrade for many (lever ergonomics, front shifting, braking). It’s also undeniably lighter and supposedly more robust although we’ll have to wait for our long-term test group to make that final call.
Unfortunately for Shimano, though, the new group just doesn’t initially strike us as quite the monumental leap in performance that we were anticipating. While the front shifting and braking performance have made significant leaps ahead, rear shift performance doesn’t seem to have changed much and there are a few small details that seem to have been uncharacteristically overlooked.
Particularly considering how Campagnolo and SRAM have stepped up their games as of late, Shimano might have a tougher fight ahead.