Race Tech

Shimano introduce Dura-Ace R9100 with integrated power meter

Integrated power meter, Synchronized Shifting, Dura-Ace disc brakes, and new pedals and wheels among updates to Shimano's flagship groupset

Shimano has pulled back the covers from the latest iteration of its flagship Dura-Ace groupset, which includes an integrated power meter.

The long-awaited R9100 Dura-Ace group, unveiled to the media ahead of the Tour de France and once again available in mechanical and Di2 (officially dubbed R9150) shifting versions, is the first major update to Shimano’s top-tier product in four years.

While the four-arm chainset remains and Dura-Ace continues to be 11-speed, plenty has changed, with the introduction of an integrated power meter and the first Dura-Ace level hydraulic disc brake among the highlights.

A chainset-integrated power meter is the standout feature of the Dura-Ace R9100 groupset

A wireless response to SRAM’s eTap system did not materialise and Manabu Tatekawa, Shimano’s global marketing chief, told RoadCyclingUK.com that such technology was not essential for such an integrated package as a road bike.

Still, there’s plenty new in the shifting department, with Dura-Ace R9100 Di2 borrowing the Synchronized Shifting technology from Shimano’s leading mountain bike groupsets, XT and XTR. With that in mind, here are the key innovation for Dura-Ace R9100 before we get into more detail.

Key innovations for Shimano Dura-Ace R9100

A power meter integrated with the chainset, able to communicate with third party devices via ANT+ and Bluetooth. Non-power meter chainset also available.
Updated electronic and mechanical shifters, each offering compatibility with hydraulic disc or mechanical rim braking systems.
More options for programmable shifting via the E-Tube system, including a road-specific iteration of the Synchronized Shifting, semi-automated system previously only available with Shimano’s flaghip MTB groups.
A ‘shadow’ style rear mech which sits directly below the cassette and so out of the ‘line of fire’ for collisions from behind. Able to handle an 11-30t cassette with a standard derailleur.
New wheelsets: 28mm wide carbon tubulars in new 40mm and 60mm depths, with a promise from the latter of a 16w saving over the existing Dura-Ace 9000 C50 hoops. Shimano’s Tim Gerrits told journalists a full carbon, disc compatible tubeless wheel, with 12mm eThru axle, would also be made available in 40mm and 60mm depths, alongside caliper brake versions with an aluminium braking track and carbon laminate rim.
New pedals and an update to the C24 training wheelset.

Team Sky used R9100 prototypes at this year’s Giro d’Italia, ahead of the official launch in France

While the introduction of an integrated power meter and top-level discs will steal the headlines, rather than placing an emphasis on the virtues of any one component, Shimano has instead focused on the advantages of integration across the groupset.

Indeed, system integration, (the favoured design philosophy of Cannondale, by coincidence), is the watchword for R9100. ‘System Supremacy’ was another phrase used with some frequency at the launch in Caen, three days before the Grand Départ of the Tour de France in Normandie.

Mismatched components reduce the level of the entire system to that of the weakest component, Tatekawa told RCUK. Officially, Shimano has set out R9100’s stall on maximising the performance of each component to minimise energy loss from the rider.

Sir Dave Brailsford and Richard Plugge, general managers of Shimano-sponsored WorldTour teams Sky and LottoNL-Jumbo respectively, were guests at the launch, underlining the status of Dura-Ace as professional standard equipment. A promotional video revealed that Team Sky had used R9100 prototypes at this year’s Giro d’Italia. A fourth victory for the team at the forthcoming Tour de France would do much to launch the group to the wider public.

That the top-level news; now let’s take a closer look at the most important updates to feature across the Shimano Dura-Ace R9100 groupset.

The FC-R9100-P power meter measures left and right leg power strain gauges located inside either crank arm, while the power meter’s ‘brain’ sits within the crank spider

Power up

The chainset is at the heart of the new R9100 gruppo and while Shimano have stayed loyal to the four-arm design first unveiled as part of the previous generation Dura-Ace, much has changed. First of all, it’s lighter (a theme across the groupset), albeit by only 7g, but, more significantly, the Hollowtech II crank arms are significantly bigger and have an asymmetric design, while the the outer chainring has been reinforced, in a move said to improve stiffness and shifting performance.

Even more noteworthy is the introduction of an integrated power meter. It doesn’t come as standard and instead Shimano will offer a Dura-Ace R9100 chainset with and without the power meter. ‘Accuracy’ is the key as far as Shimano is concerned, with the FC-R9100-P measuring left and right leg power separately, using strain gauges located inside either crank arm, while the power meter’s ‘brain’ sits within the crank spider.

Shimano call it one of the “lightest and cleanest [power meters] on the market” and say because the power meter is connected to the spider, the chainrings can be changed without affecting its accuracy.

“In the past Shimano developed the most advanced power crank I’ve worked with for use in a laboratory,” says Fred Grappe, head of performance at Francaise Des Jeux. “We took that technology and experience from the laboratory and transferred it into a system suitable for use in real world racing situations. Together with the Francaise Des Jeux team we’ve been testing it throughout the 2015 and 2016 seasons and we’re incredibly impressed with the breadth of powerful analytical information.”

The chainset will be available in five sizes – 50-34t, 52-36t, 53-39t, 54-42t and 55-42t – and with seven crank arm lengths ranging from 165mm to 180mm.

Synchronized Shift

The R9100 groupset offers riders a range of shifting options. Once again, Shimano will offer both mechanical and electronic (Di2) versions of Dura-Ace, and both have seen advancements over the previous incarnation of the Japanese firm’s pride and joy.

Synchronized Shift is the key update to Di2 and has been imported to the road world from Shimano’s electronic mountain bike groupsets, having first been introduced on XTR Di2. Synchronized Shift is “designed to simplify gear choice and reduce decision making in racing situations,” according to Shimano – in practice, shifting become semi-automated, according to which of the two Synchronized Shift modes are enabled (though it is fully customisable).

Full Shimano Synchronized Shift sees the front derailleur react to rear derailleur shifts. The front derailleur detects the position of the rear derailleur and automatically shifts to the most efficient gear for the best chain line.

Semi Shimano Synchronized Shift mode, on the other hand, sees the rear derailleur react when the rider switches from one chainring to the other to reduce the gap between gears.

Essentially, that means if you have full Synchronized Shift enabled, you should only need to use the rear shifter buttons, and if you have semi Synchronized Shift switched on, the rear mech will move to keep a constant cadence when you shift at the front. Shimano believe Synchronized Shift will be particularly advantageous in time trials or triathlons.

While we’re talking shifting, the new Dura-Ace groupset will be able to accept anything up to an 11-30t cassette with a standard derailleur, widening the available spread of gears for climbing even further.

Rim brakes or disc brakes? Take your pick

Discs for Dura-Ace

While disc brakes have had a stop-start introduction to life in the professional peloton, the launch of Dura-Ace 9100 sees Shimano add discs to its flagship gruppo for the first time.

Shimano say Dura-Ace R9100’s hydraulic disc brakes, which use the flat mount standard, are the company’s first road-specific discs, as opposed to the redesigned mountain bike stoppers previously introduced, and feature a new rotor design to improve heat management. “With an increased adaptor size, heat transfer through the rotor is decreased and more heat can dissipate through the air,” according to Shimano, citing a claimed 30^oC reduction in rotor temperature over the previous rotors. Centrelock disc rotors will be available in 160mm and 140mm sizes

Of course, Shimano will offer hydraulic disc brakes as an option for both mechanical and electronic shifting, and have significantly reworked the lever ergonomics to ensure there’s little difference between the two when using disc brakes, meaning riders can switch between mechanical and Di2, rim brake and disc brake, without noticing a difference.

Still, if disc brakes aren’t your thing, Shimano say Dura-Ace R9100’s rim brakes (available in dual-pivot or direct mount designs) are stiffer and lighter than before, offering improved clearance for 28mm tyres and a claimed 43 per cent reduction in flex over previous Dura-Ace brakes.