Tested: Shimano’s New R785 Hydraulic Disc Road Brakes

Brakes Disc

Site for our test session were the scenic slopes of the famed Haleakalā Crater in Maui. Photo Credit: Shimano/Eric Wynn

How Well Do They Work?

We’ve now had the chance to wrap our hands around both SRAM and Shimano hydro levers and the general feeling is they work exceptionally well. [Read our first impressions of the SRAM system here.] We can also say that neither system is as ergonomically comfortable as their traditional hood cousins. Both are a little wider and more boxy. It’s not a deal breaker, but it certainly needs to be pointed out.

As for the look, being less fashion conscious than some of our more high-brow road riding peers, it really doesn’t bother us too much. It’s a bike not a Versace. In fact, if you race ’cross or like to go down steep, bumpy roads, you can argue that the larger levers provide a more secure grip point. Safe to say your hands will not slip off your bars when riding in the hoods.

As mentioned above, testing ground for our short time on the new Shimano’s R785s was Maui and specifically the slopes of the stunning and majestic Haleakalā Crater (an absolute bucket list road ride). The roads there are not particularly steep, nor twisty, but because you can climb from the beach to 10,000 feet, they do offer the chance to use the brakes for an uninterrupted — and significantly long — period of time. Here again, our experience was wholly positive. Even after thousands of feet of descending fade was non-existent.

The R785 system uses an ICE Technologies disc brake rotor that traces lineage to the Saint downhill mountain biking group. The technology then trickled down to XTR for cross country riders and now has come to the road. The hallmark of these rotors is what Shimano calls FREEZA, which is a sandwich construction where stainless steel wraps around an aluminum radiator fin that is claimed to pull heat from the outside of the rotor, thus reducing heat.

That enhanced cooling factor allows Shimano to sign off on 140mm rotors for all users, in contrast to SRAM, which advises 160mm for paved use and 140mm for ’cross. [You can use 160mm with the Shimano system if you prefer.]

Wheel choice with R785 is limited to centerlock hubs, a technology Shimano created and now licenses. “We are not trying to restrict it,” claimed Lawrence. “We just feel that it is a simple system that works great for a road application. It’s very clean and we know that the look of a bike is something that is very important to a lot of roadies.”

It will also likely help Shimano sell more of its new RX31 wheelset, a 23mm wide, 28-spoke aluminum clincher with 135mm spacing centerlock hubs. Alas they’re not road tubeless and weigh a hefty 1,795 grams.

Pad choice for the R785 system is resin or metallic. Shimano recommends using metallic pads if you’ll be riding in the wet or mud (cyclocross racing), and save the resin pads for road riding, where braking noise is more likely to be an issue.

As for our extended downhill riding time at the three-day Shimano camp, we found the brakes to work exceptionally well and make almost no noise. In comparison to standard rim brakes, less hand force was needed to scrub speed. And even during a brief encounter with an afternoon squall that left us cold and soaking wet, the braking performance remained powerful. There was no need to squeegee the rotors before you needed braking force to kick in. It was there whenever you needed it, wet or dry.

But perhaps most impressive was the comforting feel of total control. We weren’t brave enough to attempt a full-on panic stop, but on several occasions we went from going really fast to really slow and never felt on the edge of skidding, much less losing control.

Are They Adjustable?

Indeed they are. Both reach and free stroke can be tweaked to the user’s liking, which determines where the pads engage the rotor. This is a great feature, especially for riders with small or large hands who prefer engagement to occur at the extreme ends of the lever pull range. It’s also something the current SRAM system cannot do.

Are They Hard To Bleed?

If you can bleed a set of Shimano’s mountain bike brakes, you can bleed the new R785s; the process is identical. The road hydro brakes use all same hoses and fixings as the mountain bike system, and run on mineral oil.

Shimano’s FREEZA rotor combined with what is essentially an XT caliper provide a solid combination of stopping power. Photo Credit: Shimano/Eric Wynn

Why The Marketer’s Nightmare Of A Name?

Shimano says that the new R785 brakes are essentially an Ultegra level offering, but it went with the non-series name so it would be easier to spec with Ultegra or Dura-Ace. It’s the same approach they took with their first compact cranks.

“Bringing the new brakes out at multiple price points would have been challenging,” explained Lawrence. “By taking this approach we provide the opportunity for more people to experience it right away.”

Will They Make You A Better Bike Rider?

Ah yes, the million dollar question. Or at least the $800/342-gram question. Of course there is no definitive right answer. If you’re a highly competent roadie (meaning you know how to use your brakes), and you don’t spend a lot of time riding in the wet, or rolling out on long, gravel grinder adventures, then the answer is probably no. Plus you’ll pay a small weight penalty, buy new disc-compatible wheels, have to put up with the larger lever hoods, and likely see your aerodynamic efficiency at least slightly reduced.

But if you race ’cross, ride carbon wheels in wet weather, want to run wider tires, don’t fret over minor aero or weight penalties, or simply want brakes that require less hand force and provide enhanced modulation and control, then hydraulic disc road brakes from Shimano (or SRAM) are worth a long hard look.

Take tire width for instance. With Shimano’s standard mount road brakes, Lawrence says 25c is the max width the company recommends. Switch to a direct mount brake set-up and that number jumps to 28c. But with disc brakes, the only limiter is frame clearance, meaning 30s or even 32s should be no problem. That’s a boon to the ever-increasing gravel grinder crowd who are looking for way to smooth out the ride and increase traction, not to mention enjoy better braking on broken riding surfaces.

It’s a similar performance-enhancing story in cyclocross. Better braking means carrying more speed into corners, more control on steep, sketchy course sections, and less mud build-up than you typically see on rim-brake calipers. It’s no surprise then that we see rampant adoption of hydraulic disc brakes at the elite level in the U.S. with pro riders such as Jeremy Powers and Tim Johnson leading the way.

In Europe, at the sport’s highest level, uptake has been slower. But Dutchman Lars van der Haar proved that you can win on disc brakes, snagging victory at the first two rounds of the UCI cyclocross World Cup series. [See full details of his bike here.]

Bottom line, we agree with Lawrence, who says simply, “People are looking for more versatility in a road bike and this will help facilitate that.” If you are one of those people, head down to your local bike shop and take a test spin. We think you’ll like the ride.

Photo Thumbnails (click to enlarge)
About the author: Jason Sumner

An avid cyclist, Jason Sumner has been writing about two-wheeled pursuits of all kinds since 1999. He’s covered the Tour de France, the Olympic Games, and dozens of other international cycling events. He also likes to throw himself into the fray, penning first-person accounts of cycling adventures all over the globe. Sumner, who joined the RoadBikeReview.com / Mtbr.com staff in 2013, has also done extensive gear testing and is the author of the cycling guide book "75 Classic Rides: Colorado." When not writing or riding, the native Coloradoan can be found enjoying time with his wife Lisa and daughter Cora.

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  • DrSmile says:

    Thank you for an informative non-biased pro review! The 1795g wheelset seems like a heavy additional weight penalty to pay. Let’s hope Shimano develops lighter Dure Ace level wheels soon. I liked descending Haleakala much more than ascending it! The Campy brakes on my Breakaway didn’t have any issues slowing me down though (even though I got drizzled on too), as you state off-road may be a better application for discs.

  • aclinjury says:

    So how does the 135mm hub fit the 130mm rear spacing on current frames??

    • Jason Sumner says:

      aclinjury — The answer is they dont. The 135mm hub will NOT fit on a 130mm-spaced frame. If running a steel frame it’s possible to cold set it wider, but most disc brake frames are 135mm spaced. Have been for some time. A couple companies were going with 130mm rear spaced disc frames, but they were a minority. At this point the industry has essentially decided upon 135mm as the standard for disc brakes. It makes sourcing hubs, etc much easier. Thanks for the question — and visiting the site.

  • mikebike says:

    + 342 g for the brakes + 125 g for frame + fork, and how much for heavier Wheels?
    Are we talking 800+ grams here?

  • scarecrow says:

    Jason if you still have access to a disc brake road bike this is what I would like to see from a test. Take the old motorcycle cornering drill of using a white line to gradually move your braking point closer to the turn entry on a disc bike vs. a dura ace brake bike. Use a 180 turn coming off a little hill or something like that. You will find out pretty clearly if the disc lets you brake later/harder into the turn. Try it in the rain as well if possible. If the disc is better you should be able to enter the turn later and still make it through with a good line etc.

  • Randonneur says:

    To the all-weather touring cyclist, there is a very important aspect of disc brakes that seems not to be addressed by any disc brake reviewer:

    How is pad-to-disc clearance controlled???

    Every mtn bike with disc brakes has the same problem: inadequate user adjustability in the field. When the wimpy pad return spring fatigues or breaks, or when the rotor becomes warped due to heat or collision, then there is no way to adjust the pad further away from the disc.

    … and if you don’t think this is a problem, you must have a full-time mechanic. I can’t remember the last mountain bike ride i’ve ridden where someone didn’t enounter a dragging disc at some point on the ride. On the road, perhaps the duty cycles are less, but the effects of a dragging disc are even more annoying.

    Brake manufacturers need to solve this problem, and reviewers need to start doing some serious testing instead of just the usual gushing of positive comments for anything with a major brand name on it.

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