Details are emerging on Shimano's new Dura-Ace R9100 series of components for road and cyclocross bikes. With hydraulic disc brake options, the new Dura-Ace raises the bar in the battle with SRAM for cyclocross bike supremacy.
Here's what we know so far about the new group with a particular eye on use for cyclocross and gravel bikes:
- Traditional mechanical (R9100) and Di2 electronic (R9150) options are offered
- Both groups remain 11 speed
- an updated Hollowtech II crankset is now available with, or without, an integrated power meter. Appears to retain the unusual 4-bolt mounting pattern used on prior Dura-Ace and Ultegra groups, which limits replacement chainring options for cyclocross, however, Wolf Tooth notably make their Drop-Stop chainring line in this pattern for riders who want a single front chainring setup for cyclocross
- System diagnostics, updating firmware, etc. possible through a smartphone app
- for the first time, Dura-Ace has a hydraulic disc brake option (previous offerings were an Ultegra-level part)
- the brake system is highlighted by a new Centerlock rotor, featuring IceTech cooling technology, stopped by finned brake pads inspired by Shimano's MTB brakes. Centerlock rotor requires a matching mount on the hub, ruling out using these on wheels with the more common 6-bolt mounting pattern popular on mountain bikes.
- Shimano's existing and updated wheel line of course has Centerlock option with tubular and tubeless options.
- As introduced on the XTR electronic mountain bike group, the shifters can be set to control both derailleurs through a single shifter if desired. As with SRAM's competing eTap system, it looks like you can configure one shifter to shift to easier gears and another to harder gears (allowing the system to manage both front and rear shifting for you, switching between chainrings as needed for the next ratio in line)
- Short-cage rear derailleur handles up to a 30t cog (hello, cyclocross!). For many riders this is enough range to run a single chainring 1x setup
- new options for hiding cables of the junction box (which has traditionally sat underneath the stem) to be routed inside a handlebar or frame
- The rear derailleur has an updated design, but it's not a Shadow+ "clutch" type like you'd find on a mountain bike. This would have been a nice feature/option, as it's highly desired by cyclocross and gravel riders using a 1x single chainring drivetrain to help with chain retention on bumpy terrain. Looks like an add-on, like the Wolftooth Tanpan, would be needed to run the new Dura-Ace shifter with a MTB clutch rear derailleur, same as with previous Dura-Ace parts.
For more official information, visit Shimano's Dura-Ace website.