Just days before the Tour de France kicks off in Mont Saint-Michel, France, Shimano released a new Dura-Ace, which we’ll likely see the pros riding at the Grande Boucle. Confirming much of what VeloNews reported on in March, the Dura-Ace updates include an integrated power meter, synchronized shifting, and Dura-Ace hydraulic disc brakes, along with some less whiz-bang but still important updates like lighter components and improved shift functions.
Shimano’s new power meter certainly has a clunky name — the FC-R9100-P — but the meter itself looks quite svelte, almost hidden behind the crankarm. The device is built into the new Hollowtech II crankset that maintains its four-arm design. What we didn’t know or expect when we wrote our article in March was that the power meter will use dual-sided strain gauges that are internally hardwired together for accurate measurements regardless of pedaling position.
The power meter is nearly hidden. You can only see a small control unit in the crank spider that has an LED light for indicating if the integrated rechargeable battery is charged and if the system is on. The magnetic charging port is also located in this control unit.
The meter uses a single rechargeable battery that powers the entire unit, and firmware for the meter can be updated wirelessly. It uses Bluetooth and Ant+ communication and will come in a range of crank-length options: 170, 172.5, 175mm (with chainrings) or 165, 167.5, 170, 172.5, 175, 177.5, 180mm (without chainrings).
Di2 synchronized shifting
First introduced with Shimano’s XTR Di2 mountain bike group, Synchro Shift is now available with both Dura-Ace Di2 R9150 rim and R9170 disc brake options. This confirms our reporting from March and we’re excited to see the Synchro Shift for the road. The “Full Synchro Shift” platform acts just as it does on the mountain bike system, which is essentially automatic front shifting, requiring the use of only two shift buttons to shift the entire drivetrain. When the derailleur reaches a certain point (which is customizable) on the rear cassette, the front derailleur shifts while the rear derailleur shifts in the opposite direction. The rider gets similar gear jumps with each button push. It’s a system that is made possible by Di2’s incredible front shifting.
In addition to traditional “full” Synchro Shift, riders can optionally select “semi” Synchro Shift. This new mode reacts when the rider shifts from one chainring to another, automatically shifting the rear derailleur to minimize the gear step, thus preserving the rider’s rhythm.
Synchro Shift will be made available for all previous 11-speed Di2 road component groups with a new Di2 firmware and accessories in November 2016.
Rim and disc brakes
The new R9100 group sees updated rim brakes with redesigned dual-pivot and direct mount calipers. They promise improved stopping power and increase tire clearance up to 28mm tires.
But the big news is the Dura-Ace groups now have their own Dura-Ace-level hydraulic-disc braking systems. The brakes have been redesigned to shed weight, have better heat management, and better braking performance and reliability. The new Dura-Ace rotors have an alloy core, which now extends to the spider of the rotors, allowing more heat to dissipate into the air and not into the brake system. The BR-R9170 flat-mount caliper has a lower profile and weighs a claimed 256 grams. Centerlock disc rotors will be available in 140mm and 160mm sizes.
The new Dura-Ace hydraulic dual control levers are nearly identical to the mechanical version, keeping that slim, racer-friendly shape and feel that we love.
Beyond the big updates, Di2 gets a full makeover, shedding weight and seeing redesigned components for improved shifting, more gearing options, and better ergonomics.
The Dura-Ace FC-R9100 Hollowtech II crankset has been reshaped to add claimed strength and rigidity while also dropping weight. It builds upon the four-arm design of previous Dura-Ace cranks and offers new chainring configurations that work better with bikes with shorter chainstays. The R9100 crankset has also been adapted for the latest disc brake frame design without needing to increase the q-factor.
Where the previous version of Dura-Ace drivetrains was designed to only work with an 11-28T cassette or smaller, the new version expands its range, now accommodating up to an 11-30T cassette. We’ve seen 11-32T cassettes work on older versions of the group, so we’re guessing this will still work, only more smoothly.
A new, narrower chain comes along with the updated group. The HG901-11 chain features an asymmetric plate design that Shimano says will improves shift quality, increase chain retention, and reduce drivetrain noise. Dura-Ace has always been on the quieter side, so reducing noise should make it nearly silent.
Dura-Ace’s previous version had a long front derailleur arm that ran into problems as bike frames changed to accommodate wider tires and used shorter chain stays. To combat this, Shimano came up with an internal toggle mechanism. It works just as smoothly as the long-arm design but can be fitted on complex frames.
The rear derailleur attaches to the bike via a direct mount hanger. The Shadow rear derailleur borrows from the mountain bike group and is positioned in line with the bike rather than sticking out into the wind. Also, there is now only one specification that will cover the full range of all cassette options.
Along with the updated drivetrain, Dura-Ace wheels get a full overhaul as well. Shimano introduced two new wheel platforms, the 40mm deep C40 wheels and the 60mm deep C60 wheels. Both have the same rim width so swapping between wheel sets won’t be a problem. Both also have rim brake options with quick release compatibility as well as center-lock disc brake options with thru-axle compatibility.