Stop on a dime.
Shimano debuts its hydraulic disc brakes as an Ultegra-level component in the form of the R-785 Di2 Hydraulic STI Lever and Disc Brake Caliper Set. This is a bit of a flip-flop for Shimano, but presumably it's because the UCI has not yet approved disc brakes at the pro-level for which its flagship Dura-Ace groupset is intended. So rather than the traditional trickle-down effect that Ultegra is normally imbued with, in this case it is at the top from the start.
The Road disc brake system was designed to be compatible only with Di2 electronic shifting. To this end, the front profile is higher than the Ultegra profile in order to hold the fluid reservoir for mineral oil. They feature reach and stroke adjustments so that your hand position is optimized. Most importantly, braking power is consistent no matter what the conditions. The brake calipers features Shimano's IceTech technology. This technology dissipates heat more effectively so that the brakes grab faster and the pads last longer. This is done by cooling fins in the braking pads.
The Shimano ST-R785 Di2 Hydraulic STI Lever and Disc Brake Caliper Set does not include the rotors.
- IceTech technology
- Di2 electronic shifting
- Reach and stroke adjustments
View more Road Bike Disc Brakes
Reviews & Community
Need Flat Mount Option
- Familiarity: I've used it several times
These are great but it would be awesome if there was an option for flat mount calipers.
Great shifters and hydro brakes :-)
- Familiarity: I've put it through the wringer
I have a background in MTB'ing so the lack of hydraulic disc brakes was an adjustment when I first started riding road. Now, years later, I have 2 bikes with these shifters and they work great. I may upgrade to the new dura shifters when they come out so I can have the button and the better button action. A couple small "nagging" issues with the r785's is that they rattle if your hand isn't on them and that they feel a little "fat" on the hoods.
Are the calipers post mounts?
Are the levers compatible with the rest of the Ultegra 11 speed 6800/6870 groupset?
These are compatible with Di2 systems and derailleurs only. The RS685 is the lever set you will need for mechanical derailleurs:
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Do you need adjusters on the frame to accomodate the brake calipers? In particular for fitting them on a NINER BSB 9 RDO 2016 frame and running 160 mm rotors (F and B)?
The 20i6 BSB is available with these installed, so they will definitely fit your frame. I have a 2015 with them and the brakes do require spacers for 160mm rotors. You don't need them for 140s.
By set does this mean Left and Right lever and calipers and hoses?
You are correct, it does come with both left and right. They will add a total of 1724g to your bike.
More questions? Just call or email me, directly.
A complete set (2 levers & calipers) really weighs 1724gm? Ouch, that is 3.8lbs not including hoses, fluid and rotors!
Bryan, You're looking at 1000g for standard Di2 levers and rim calipers without cable or housing. These brakes do include the hosing and oil- no rotors. Sure, Its a bit more weight, but most bikes are well below the UCI weight limit and stopping later makes you go faster every time.
Not to nit pick, but from your own data:
Shimano Ultegra Di2 ST-6870 11-Speed Shifters are available in one size and in the color Grey. Each pair comes in at a claimed weight of 295g (Actual Weight:Gray, 6870: 323g)
The Shimano Ultegra 6800 Brake Calipers are available in one size and one color (Actual Weight: Gray, One Size: 335g).
That makes for only 658gm for Ultegra Di2 shifters & rim calipers (add cables), but still near 1kg lighter than the hydraulics.
From what I'm reading about the hydrualic stuff elsewhere, the shifters Actual weight: 508 grams (lever pair only)) + the calipers, etc... I think you have doubled the pair weight to arrive at 1724gm which seems excessive.
Hint, you need to correct your product info which is stating this set is some 900gm more than actual.
Bikerumor has a posting with photos of actual weights: shifters: 255, calipers: 98, pads: 20. Double that up for a pair comes to 746gm total, plus hoses and fluid.
A couple competitor websites also have data in this same ballpark, ie:
1- Claimed weights: Shifter - 515g, Caliper - 263g, Hose - 61.5 g
2- Actual weight: 739 grams (Levers and calipers)
Strange nobody here thought that maybe 1724gm (3.8lbs) was just a tad heavy for a set of shifters & calipers (w/pads) and hoses.
Once you go hydraulic and electronic...
- Familiarity: I've used it several times
Di2 ain't nothing new - it works perfect every time, all of the time. That's old news. These brakes...holy moly. Take your sweetest mountain bike brakes and stick them inside a Di2 lever. Not grabby, not too strong, and as easy to modulate as a soft bristled tooth brush on a sunny Friday morning.
You can go faster when you have more control - and these are the ticket. I'm a nerd for having the brakes engage where I want them to within the lever stroke, and you can dial this in with the reach adjustment, which really was the icing on the cable-less cake. I was inclined at first to go 1x with the SRAM setup, but the lever feel of these brakes is amazing, and I like the hood shape better.
Are these levers compatible with hydraulic rim brakes, such as those made by Magura or SRAM?
Definitely no with SRAM/Avid. They use DOT fluid while Shimano uses Mineral Oil. Not sure about Magura brakes.
No, Every manufacturer has there own flow rates, valve sizes, etc so nothing is cross compatible between brands. Sorry