MichaelB wrote:Wonder what the new DA levers will look like ?
Very very similar to 9000/9070.
Following the official launch yesterday of new R9100-series Dura-Ace, here's the pre-emptive answer to the compatibility questions. The good news is that despite the significant geometry changes to both derailleurs, they're fully compatible with existing 11-sp + 4700 Tiagra shifters. Brake calipers likewise are a match with existing 7900 & later levers. All levels of road hydraulic brake levers and calipers are interchangeable. The only bit that comes with a slight question mark is the crank/FD pairing. The new crank has slightly wider chainring spacing, with the small ring being brought inward very slightly. We're only talking about half a millimetre, but apparently some frames limit how far in the older derailleur can be wound, so may not work as well as it could with the new crank. As such it's recommended to pair the new crank to the new FD, but in reality it's generally unlikely to be an issue.
On the Di2 front, disregarding ye olde 7970 10-sp. Dura-Ace, all shifters, derailleurs and upper junction/control boxes, both road and MTB will talk to each other, but certain functions such as Synchro shifting are only available with certain derailleur and junction combinations.