While aimed primarily at road riders, there are some features of Shimano's newly announced Dura-Ace 9100 group that cyclocross racers and gravel riders may find of interest.
Dura-Ace Hydraulic Disc Braking
Most notably is the addition of Dura-Ace level hydraulic disc brake calipers. The R9170 caliper is a flat mount design and is said to be "tuned for road applications." Paired with the caliper is a new RT900 rotor said to manage heat better than the existing RT-99 Ice rotors. And maintenance is said to be easier with easier tool access and one-way bleeding.
Weight for the R9170 calipers is a claimed 256 grams per pair. The new RT900 rotors come in at a claimed 119 grams for 160mm rotors and 96 grams for 140mm.
Dura-Ace Power Meter
The R9100-P is a Shimano power meter designed into the new Dura-Ace crankset. Dual-sided strain gauges are internally hard wired together in an effort to provide reliable performance and accurate power measurement. The system has a single rechargeable battery powering the entire unit and the ability to wirelessly update firmware.
The power meter is said to offer ±2% strain gauge power measurement accuracy, riders have the ability to swap chainrings without affecting power measurement, the unit offers Bluetooth and ANT+ wireless communication and like the standard crankset comes in 170, 172.5, 175mm crankarm lengths and ring combinations of 50-34T, 52-36T, 53-39T.
New Dura-Ace Cassette
To go with the new crankset and mated to the revamped rear mechanism, discussed below, there is a new 11-30 R9100 cassette expanding the gear range some. The cassettes in each configuration, 11-25, 11-28, 12-25, 12-28 and the new 11-30 each feature an alloy spider arm and five titanium sprockets.
Revamped Dura-Ace Brake/Shift Levers
As seems to happen with most groupset redesigns, the brake/shift levers also recived some modifications. The new mechanical Dura-Ace 9100 levers come in two modes, the R9100 and the R9120 hydraulic model. The right, rear lever now has a shorter stroke for faster rear shifting and the left, front lever receives new internals for lighter front shifting operation, paired with a newly designed front derailleur.
The levers feature more adjustability, up to 14mm for the R9100 mechanical brake model and there are more ways to customize overall lever position. And the hoods have been redesigned for improved ergonomics
Claimed weights for the new Dura-Ace Dual Control levers are 365 grams for the R9100 mechanical braking set and 505 grams for the hydraulic R9120 pair. The mechanical levers will retail for $500.99 USD per pair, without brake calipers, while the mechanical shifting/hydraulic braking levers, which come paired with the new R9170 disc calipers are $1,029.98 USD.
On the Di2 side of things, both Di2 ST9150 mechanical brake and ST9170 hydraulic brake Dual Control levers also feature a revamped and refined hood shape. The levers also are said to produce a more defined shift click for a more intuitive feel, quicker shifting operation and expanded E-Tube customization to allow every switch the option to independently turn on or off multi-shift. Weights for the new Di2 levers are a claimed 230 grams for the ST9150 units and 360 grams for the ST9170 haydraulic levers. The ST9150 units cost $623.99 USD and the ST9170 levers with brake calipers are $1,155.98 USD.
Revamped Dura-Ace Derailleurs
Interestingly, Shimano's new 9100 Dura-Ace mechanical rear mechanism is a Shadow unit, but not a Shadow Plus derailleur, thus it does not feature a clutch. So it seems for the interim that Shimano is not ready to fully embrace 1x for the road side of things. The Shadow aspect of the unit should help limit damage in the event of a crash and total capacity is said to be 35 teeth, which is nice for low gear seekers. The new R9100 Dura-Ace rear mechanism has a claimed weight of 158 grams. The 9100 rear mechanism will retail for $207.99.
The new mechanical front derailleur, as mentioned above, does offer a claimed lighter shifting operation. But there's also improved ease in setting the R9100 front derailleur. What Shimano is calling Toggle is a new link construction that does not require special tools. There are also more cable routing options and an integrated cable tension adjustment. Total capacity is said to be 16 teeth and the R9100 front derailleur is said to tip the scales at 69 grams and will sell for $108.99.
The new R9150 Dura-Ace Di2 rear derailleur sees a ground-up re-design, which, like the mechanical unit, takes advantage of Shimano’s Shadow architecture. And the new R9150 front derailleur is said to deliver improved shift performance even under high pedaling torque.
Weight for the new Di2 derailleurs are a claimed 104 grams for the front mechanism which will sell for $371.99 USD, and 204 grams with a retail price of $601.99 for the rear with the same tooth capacities for each as their mechanical counterparts.
Updates to Dura-Ace Di2 Software
R9150 and R9170 Dura-Ace riders can, if they like, take advantage of Shimano's Synchro Shift, first introduced in XTR Di2 M9050. The programmable Di2 Synchro Shift, as the name suggests, synchronizes front and rear shifting that can be custom programmed.
Riders can opt between “Full” Synchro Shift and “Semi” Synchro Shift. This new mode automatically reacts when riders front shift and automatically shifts the rear derailleur to minimize the gear step, in an effort to preserve the rider’s rhythm.
Shimano Synchro Shift will be available for all previous 11-speed Di2 groups via new Di2 firmware and accessories in November of this year.
New Dura-Ace Wheelsets
There are new Dura-Ace wheelsets as well, both for rim and disc brakes.
For cyclocross racers who prefer tubular wheels, the new R9100-C40-TU, carbon tubular or thru axle WH-R9170-C40-TU, carbon tubular are the go-to option. Each features a wide section rim, improved drive rigidity, full carbon rim construction, and a titanium freehub body. The quick release C40 wheelset weighs in at 1,343 grams while the thru axle option is 1,389 grams. The tubular C40 wheelsets will cost $2,402.99 for quick release and $2,445.99 for thru axle.
There is also the deeper sectioned WH-R9100-C60-TU carbon tubular or the thru axle WH-R9170-C60-TU carbon tubular each with the "D2" wide section rim, improved drive rigidity and added Aerodynamic performance. The quick release version comes in at 1,471 grams and the thru axle version is a claimed 1,492 grams. The C60 wheels will sell for $2,628.99 for quick release and $2,668.99 for thru axle.
There are also tubeless wheel options for riders looking to forgo the work associated with tubulars. Both the C40 and C60 rim depths come in tubeless compatible models and interestingly each only comes in a thru axle design. The C40 tubeless carbon wheels weigh a claimed 1,557 grams and the C60 version is said to weigh 1,644 grams. The C40 tubeless wheels will sell for $1,969.99 USD and the C60 tubeless wheelset will go for $2,078.99 USD.
More info: duraace.com