Shimano Ultegra Di2 R785 Road Disc – First Look

Anyone who reads AeroGeeks will find that our technical editor (Devon) waxes poetic about the benefits of hydraulic disc brakes on bikes. They stop better, resist fade better, offer better control and belong on every bike under the sun. Today, Shimano has heard his fervent prayers to the cycling gods and announced Ultegra Di2 R785 Road disc shifters and calipers. You read that correctly. Ultegra Di2 with hydraulic road brakes. Now is the appropriate time for cheering.


R785 is the first of its’ kind; shifter levers utilizing Di2 actuation for minimal space requirements under the hood, leaving room for the master cylinder… without the massive increase in surface area that a mechanical setup would require. What this means is that the hoods will see only minimal changes, with all the goodness of hydraulics crammed inside. But that’s not all that’s going on.


With R785, the calipers are of a two-piston design to ensure both stopping power under any conditions, as well as an excellent ability to modulate stopping power. Furthermore, the heat dissipation of the entire system has been maximized to be able to handle a temperature delta of 200 degrees by utilizing not only finned disc rotors, but finned brake pads, as well, and will be available in 140 and 160mm variants (via Shimano’s ICE technology).


Let us not forget that this also means that any Di2-equipped cyclocross rider now suddenly finds himself in possession of a nearly bolt-on solution to his braking woes from mud and grime, so he can now brake later, turn later, and go faster. In fact, Shimano is also releasing an 11-speed hub intended for just such a CX rider. The HB-CX75 will take a 140mm rotor, just for them, in addition to an 11-speed disc brake wheelset called WH-RX31.

More details on this system are forthcoming, and will be widely available in November of this year.

2 responses to “Shimano Ultegra Di2 R785 Road Disc – First Look

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