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.