With the introduction of its top-level Red group last fall, upstart road component manufacturer SRAM took a shot directly across the bow of the industry leader. Shimano’s soon-to-be-released 7900 series Dura-Ace group is clearly a direct response to Red and it adds considerable firepower to the full-on techno’ wars raging among the three big component manufacturers.
While Shimano has used its electronic group as a teaser for the last three years, prototype examples of the 7900 mechanical Dura-Ace group first appeared this spring. Even then the components looked very much like prototypes and not nearly as polished as the latest crop of Electric Dura-Ace parts. But since the competition in road components is so hot these days, prototypes in any form that make it into ProTour competition create a buzz, especially when they come from a manufacturer as large as Shimano.
The old 7800 series Dura-Ace has been in service in the professional peloton since 2003. It was released to the public as 2004 equipment and, although it wasn’t the first 10-speed group to market, it was trend-setting. Five years later, the 2009 redesign of Dura-Ace will set the stage for the brand’s future and the Japanese giant took some inspiration from its competition.
“If you were to look at the last generation of SRAM product and then look at ours you could absolutely walk away with that impression,” said Devin Walton, Shimano’s PR manager. “The reality is that a lot of the things you see integrated at this level are things that have already been done at more affordable levels of our product. But also this is a normal evolution of product. We are absolutely going to respond to what the market wants. If somebody makes something with a favorable feature and we’re making a new product, we wouldn’t turn away from that just due to pride.”
Without further ado, here is Shimano’s official introduction of the new 7900 Dura-Ace group, which will be available for purchase this fall.
FC-7900 Dura-Ace crankset
The new Dura-Ace crankset features a hollow outer chainring. Likely due to the ring and further refinement of its hollow forging process Shimano claims the crankset is 20 percent stiffer and 15 grams lighter than the 7800 edition. Other changes include redesigned chainring teeth said to improve chain interface and power transfer, as well as improved bottom bracket seals to reduce contamination and friction. The new crankset does not adopt Shimano’s 970 XTR non-drive crank arm attachment; instead it retains the pinch-bolt style design of the old crank.
After a long wait Shimano will also carry a Dura-Ace branded compact crankset (34/50) with the 7900 series group.
The latest word of Shimano’s yet-to-be-sold Carbon Dura-Ace crank is that it will keep the 7800 series designation and chainring style. Its revised release date is later this year, likely fall.
The initial release of 7900 does not include a newly designed triple crank.
ST-7900 Dura-Ace Dual Control levers
The new STI Dual Control levers offer a refined ergonomic shape and are claimed to be 40 grams lighter. 7900 will be known as the group in which Shimano fully accepted carbon fiber. The new STI levers feature unidirectional carbon fiber lever blades, which are responsible for much of the reduced weight. Shimano also took the opportunity of a lever redesign to tuck both the brake and shifter cables under the handlebar tape, putting it in line with its competitors. The shifters are held to bars via titanium clamps and bolts. Shimano claims that the revised internal mechanism along with a new PTFE-lined casing keep the action as light as previous designs.
The shift stroke for the rear derailleur has been reduced by 20 percent for quicker shifts, but a 7800 rear derailleur will work with the new group and vice versa. A built in reach adjuster allows for fine-tuning the fit for riders with smaller hands.
The shifters continue to offer integrated controls for a new FlightDeck computer (SC-7900), which has been updated to include heart rate, altitude, grade, cadence, gear position, and is directly downloadable via a wireless connection. The new SC-7900 computer is completely wireless via the use of a coded frequency.
CN-7900 Dura-Ace chain
The newly designed Dura-Ace chain has a asymmetric design whose redesigned plates are said to improve the contact interface with the cogs and reduce the chance for chain suck on the chainrings. Shimano also claims greater durability with less noise and smoother function. The new chain uses hollow pins and weight drops by over 18 grams. Likely the best improvement is the addition of a removable master link. The master link marks a welcome departure from Shimano’s traditional Hyperglide connection pin; the SM-CN79 quicklink provides a reusable connection and removal point for the chain. Even better, the quicklink can be used on any Shimano 10-speed chain, while the new chain can also be assembled with a traditional Hyperglide 10-speed connection pin.
RD-7900 Dura-Ace rear derailleur
The rear derailleur further illustrates the brand’s acceptance of carbon fiber with a carbon fiber pulley cage. The rear derailleur loses another 16 grams. The new mech is compatible with wider range cogsets and can accommodate up to a 28-tooth cog.
FD-7900 Dura-Ace front derailleur
Shimano claims its new Dura-Ace front derailleur cage design eliminates the need to manually trim the front shifting, therefore the extra detents have been eliminated. The redesigned front derailleur linkage is wider and the spring is tweaked to reduce the effort required at the shift lever. This is a tough one to stomach, as the absence of trim for both chainrings is one of our top gripes when it comes to SRAM’s road groups.
BR-7900 Dura-Ace brakes
According to Shimano its new Dura-Ace brakes have “Increased linear response, improved braking power and reduced weight.” In addition the company claims that its new brake pad compound doubles wet condition performance, while improving dry power by 20 percent. If this proves true, Shimano will have a brake that’s untouchable in terms of power; the current version still serves as the industry’s benchmark. The “increased linear response” is spawned from a redesigned caliper arch, while the cable stop is lower profile, creating smoother cable routing, which is said to reduce cable friction. The brakes feature a spring tension adjuster and adjustable toe-in for the pads while dropping nearly 30 grams from the combined front and rear calipers.
FH-7900/HB-7900 Dura-Ace freehub and front hub
Both the hub and freehub body have new designs that are said to improve rigidity for efficient power transfer and sharp handling. The bearings have been updated with a tool-free bearing adjuster. The freehub retains its titanium shell and quick engagement internals.
CS-7900 Dura-Ace cassette
Shimano claims further shifting improvements by creating a stiffer and lighter aluminum carrier along with re-engineered tooth profiles. The largest four cogs are titanium. Shimano claims the cassette is 10 grams lighter. The 7900 Dura-Ace cassette will be available in the following combinations: 11-21, 11-23, 11-25, 11-27, 11-28, 12-23, 12-25 and 12-27.
We expect to see the production version of the 7900 group pop up in ProTour competition in the lead up to this July’s Tour de France. While the new group is lighter than the previous version, it doesn’t trump either Campagnolo or SRAM when it comes to weight, so the true testament of the redesign’s success will come through riding it and its performance on and off the racecourse.
“Creating something that’s as lightweight as possible is an important goal especially for a product like [Dura-Ace], but it’s never going to be sacrificed for critical features, features that will actually increase endurance, reduce fatigue as well as insure that you’ve got a product that isn’t going to fail you when you need it most,” said Walton.
“Those things are going to trump reducing weight, and I think ultimately we’ve always been more conservative that way and that’s paid off in competition. We’re making it with high enough performance so that it can be used by ProTour riders; we also realize that this is one of those sports that you can go out and buy the same stuff they’re riding in the Tour de France. Who knows how long they’re going to ride it? We always think about the racer and that’s the environment this product is developed in, but the reality is that the vast majority of it is purchased by people who aren’t racers and they might not reinvest as soon as someone who races does. It’s like if you could buy Formula One parts for your car, yet still drive the thing daily.”
So the question is: Will Dura-Ace 7900 work so well that consumers, and racers, won’t mind taking a quarter pound (roughly) weight penalty to ride it? For that answer, we’ll just have to wait and see.
|Components||Dura-Ace 7800 Weight (Grams)||7800 (2008) Pricing||Dura-Ace 7900 Weight|
|Chain (116 links)||280||$50||262|
|Rear Hub 7850||267||N/A||N/A|
|Weight w/out Hubs:||2181||2052|
(2009 Dura-Ace 7900 pricing is not available)
FILED UNDER: Bikes and Tech