Second Impressions: Shimano’s R785 Hydraulic Road Disc Brakes Totally Redeem Themselves

shimano r785 hydraulic road disc brakes ride review

After riding SRAM’s Hydro-R disc brakes at their launch and being very impressed (long before the recall), it was with quite a bit of anticipation that I hopped aboard a preproduction set of Shimano’s R785 hydraulic disc brakes at Interbike’s outdoor demo last year.

Unfortunately, that ride didn’t go as well as I’d hoped. Probably as well as Shimano had hoped. The set I rode had the dark cloud of “preproduction” and a bit of a rushed set up hanging over it. The power felt lacking, and left me with the impression that someone of my size (6’2″, 185lbs at the time) might be better served by 160mm rotors rather than the quaint 140′s they recommend for all users. Something seemed off, but given my overwhelmingly positive experience with their mountain bike brakes, I chalked it up to the set needing to be rebled, something to which the attending tech rep concurred. Thus, I left optimistic, looking forward to a second run.

That time came just a few weeks ago, and it proved to be a much better testing ground than the aqueducts of Nevada’s deserts…

shimano r785 hydraulic road disc brakes ride review

My real test took place at the Baller’s Ride aboard the all-new Alchemy Aithon gravel road bike. The first day’s shakedown ride was a mere 30-ish miles of rolling hills and gave me the opportunity to feel them out, testing the limits of braking power before things locked up. I also dragged them for a bit to see how they tolerated heat.

shimano r785 hydraulic road disc brakes ride review

So long as you’re combining their Freeza rotors with the Ice-Tech finned brake pads, Shimano recommends 140mm rotors for all rider sizes/weights. Despite my initial skepticism, they proved to be plenty powerful and held up to dragging on long descents. I didn’t totally abuse it, trying to alternate between front and rear, but I did maintain consistent application for long stretches in order to both test them and keep speed in check. On several long descents, I gave them a little extra squeeze after dragging just to see what they had left in them. I’d argue you really don’t have much control when you’re topping 40mph on skinny little tires, but these seemed to provide more stable deceleration than any rim brakes I’ve used. I’m happy to say I’m not writing this from a hospital.

shimano r785 hydraulic road disc brakes ride review

All seemed right in the world, so why not push it?

shimano-hydraulic-road-disc-brakes-ride-review10

For the actual Baller’s Ride, an 80 mile gravel-and-paved road grunt with more than 8,000 feet of climbing (and descending), I switched from the ENVE Smart Disc wheels installed on the bike to Boyd’s new Altamont Disc with thinner, lighter tires. (My computer turned itself off prior to one huge descent, which truncated the recorded mileage, hence the straight line drop/path on the lower left segment. I turned it back on at the bottom.)

Boyd Cycling Altamont Disc alloy road bike wheelset for disc brakes

The one concern was having to switch to 6-bolt rotors. I brought along Hayes’ rotors since they had the most surface area of any other rotors I had laying around. Presumably, that’d offer the most heat capture and dissipation compared to more minimal rotors. Fortunately, my theory seemed to work, and braking power was equally strong held up through consistent dragging and power braking.

Besides just testing the brake’s ability to handle heat, some of the gravel road descents carried on for miles and simply required brake dragging to maintain a safe speed. The Baller’s Ride presented some of the more treacherous real world conditions any road or ‘cross bike is going to see, and these brakes handled them flawlessly. At the end of the day, I had zero complaints…and that’s not even running Shimano’s own heat shedding rotors. That’s particularly important considering the Freeza rotors are ONLY offered in Centerlock. If you’re upgrading an existing bike or just really want a sweet set of wheels that are only offered with 6-bolt mounts, my experience suggests it’s not a problem to mix and match their calipers with a high quality, substantial rotor from someone else. I would strongly discourage trying to save weight at the rotors with a minimal, wide open design – you don’t want to repeat my mistakes. Of course, you do any such experimentation at your own risk.

shimano r785 hydraulic road disc brakes ride review

Shimano’s hood ergonomics for the Di2-specific hydraulic braking levers are fantastic. They remained comfortable ride after ride, hour after hour. Lever feel is smooth as butter, which is what all hydraulics should feel like. Unlike the fast-then-slow ServoWave pad movement pattern on their MTB systems, the road brakes use a much more linear movement. Brake force comes on smoothly, not suddenly, and gives you plenty of power progression before lockup. There’s a ton of control here.

shimano r785 hydraulic road disc brakes ride review

Even better, that full braking power and modulation is achievable with only one finger tip at the very top of the lever. The hand positions are shown above provided a secure grip and are how I rode all of the gravel descents. That’s huge when you’re screaming down a gravel road at 25+ mph and hit a washboarded corner that rattles your bones and you need that death grip to avoid full frontal road rash. So I’ll reiterate for emphasis – you have FULL BRAKING POWER with a mere fingertip positioned in the least leveraged part of the lever. And this feeling should never degrade due to cable housing contamination. If you’re a pure roadie that’s never used mountain bike hydraulic brakes, this will change your life. If you’re a switch hitter, you’ll understand…it feels just like you think it should. Which is amazing.

shimano r785 hydraulic road disc brakes ride review

Once back home from Baller’s I went for a few more road rides on normal, rolling terrain and stop-and-go downtown sections. Still with the Hayes rotors, it was confidence inspiring and exactly what I want from braking. The slow pad retraction issue I experienced at Interbike was gone, likely because Matt at Alchemy had been riding this bike for a while and the piston seals were broken in.

shimano r785 hydraulic road disc brakes ride review

Heck, they even have me rethinking 140mm rotors up front. With nothing but positive experiences with their mountain bike brakes, this is what I thought Shimano’s road offerings would be. This is what I wanted them to be. And, now, this is just plain what I want.

shimano r785 hydraulic road disc brakes ride review

One note on mixing and matching: If you plan on going the other way, using Freeza rotors with non-Shimano calipers, ask your local shop to let you install a wheel with them before buying. Shimano’s two-piece rotor’s carrier is thick and extends far enough out to create clearance issues with some other calipers. I’ve tried them with Avid and Hayes brakes with the following adjustments to make them fit:

  • Avid mechanicals’ brake pad tabs make contact, but can be filed down (particularly the inside one) to clear the carrier.
  • Hayes CX-5 calipers barely touch, but small thin washers between the caliper and fork/adapter/frame will let it clear the carrier while still providing enough pad contact.

Again, any such modifications are made at your own risk, but wanted to share so you can check fitment before making the switch.

Unrelated, if you’re searching in vain for Shimano’s R785 brakes on their website, you’ll need to look under Ultegra > Di2 > Disc Brake Series. Check our original tech post on the R785 here and the new 105-level RS685 hydraulic braking with mechanical shifting here.

Bike.Shimano.com

Comments

Randall - 06/09/14 - 11:05am

” Avid mechanicals’ brake pad tabs make contact, but can be filed down (particularly the inside one) to clear the carrier. ”

It’s also soft enough metal to be clipped off with a wire cutter, for people who don’t like unnecessary filing and aren’t worried about a slightly sharp tab-edge.

mudrock - 06/09/14 - 11:38am

Your reviews get better all the time. The Centerlock restriction is a dealbreaker for me, tho. Plus I’m a Sram fan. Holding out for wireless! TRP Hylex with Sram wireless, if they ever release remote shifters.

David - 06/09/14 - 12:07pm

@mudrock Don’t worry about Centerlock too much. The only reason to go that route is to use the 140mm rotor [IMHO]. Shimano makes IceTech rotors [RT86] in 160mm which do the job just fine. Not quite as fancy/expensive as Freeza. I use 6-bolt standard XT rotors with my TRP Hylex, and they work quite well.

The main/only reason to go with Icetech or Freeza is to maximize heat loss of the rotor. Cooking your brakes is bad, but how long do you have to drag a brake before it gets too hot? As an occasionally timid mtn bike rider, I’ve dragged my XT rear brake for several minutes at a time down some misbegotten goat path and not had it fail in the slightest. Of course, that’s not a real repeatable test – maybe one of the German bike mags has done a “Mach Schnell to Fail” test with Hope/Shimano/Formula/Avid/Magura…

Flip - 06/09/14 - 12:11pm

@mudrock – It’s not restricted to Centerlock, but Centerlock is the only rotor capable of shedding heat in the way Shimano intends them too. You can buy and use any rotor you want except for the Freeza. You can do 160 Ice-Tech 6-bolts, if you’re so inclined, and you’ll have much of the heat dissipation properties that Shimano intends.

Why people don’t like Centerlock is beyond me – it literally solves every single problem I can think of with rotor attachment.

Flip - 06/09/14 - 12:20pm

@david – Actually, Tour magazine did just that, and ran a test of the Freeza rotors on a long, steep downhill. They dragged the brakes the whole way, and by the end, the center had melted out of the rotor. Of course, the moral of the story is don’t drag your brakes down a mountain for ten miles. There’s a video out there that’s worth looking for.

Jason - 06/09/14 - 12:44pm

How difficult are the hoods to re-install? I also tested the brakes at Interbike and the hoods were a real pain to snap back in place.

Derek - 06/09/14 - 12:47pm

Here’s the Tour magazine test (German skills not needed to see results of test)

http://www.tour-magazin.de/technik/so_testet_tour/video-praxistest-scheibenbremsen/a30097.html

mudrock - 06/09/14 - 1:02pm

I’m fine with Centerlock if someone wants to give me the wheels. But I now have Stans and want to stay with them (I’m sure you can get them built with Shimano hubs if you want to pay custom prices). Centerlocks aren’t that readily available. Shimano continues the tradition of creating their own proprietary standards. That’s what pissed me off about them 30 years ago when i worked in shops, and they’re still at it today.

Clancy - 06/09/14 - 1:51pm

Interesting video from Tour Magazine. Not knowing German I wasn’t able to tell the total weight of the bike or rider. I’m assuming that the large block in the triangle was added weight? I’ve seen the Shimano video where they tested the rotors, with recording equipment hooked up and added weight as well, but no melted rotor. I would like to see comparison tests done, same conditions, with caliper brakes and carbon rims.

dislivello - 06/09/14 - 2:15pm

Only one .. pads touch disck when u stat to push w weighr on front wheels. Other is safe safe safe system

Derek - 06/09/14 - 2:19pm

@Clancy, according to the thread on WeightWeenies, weights were added to the bike in order to bring the total weight (bike+rider) to 100 kg. I don’t speak German so I can’t confirm.

Tyler Benedict - 06/09/14 - 2:36pm

Flip – the downside is compatibility with the vast majority of hubs out there, but as others have mentioned, 160mm rotors and up can be had in 6-bolt versions.

Jason – they do take a bit of finagling to get flush again, but they’ll get there.

Mudrock – thanks for the compliment.

David - 06/09/14 - 2:47pm

Derek, Flip – Thanks for the Tour video. That is impressive – melting the Al out of the rotor [at least that's what it looks like]. Mach Schnell to Fail indeed! I think I’ll stick with standard 160s…

K11 - 06/09/14 - 3:40pm

@tyler Benedict-well done review and article.

@mudrock- i was an early adaptor of center lock systems. i entered the game as soon as DT swiss offered hubs in this option (as dt was a personal preference). Once you make the initial entry into center lock, you wish you would have done it sooner. I also hate proprietary parts, but this system is really slick. Ya the hub option and rotor options ARE more limited, but this center lock thing is gaining momentum, which makes me happy. White industries as recently jumped onboard with a center lock hubs (which is another hub preference of mine) There are a handful of others and handful of rotor companies, won’t list them now, but this system is quietly gaining popularity and acceptance. i tell everyone, that it’s worth a look, especially now, ten years later.

any 6bolt rotor can be converted to center lock by using shimano RTAD05

Alex - 06/09/14 - 3:42pm

The german magazines are known to test parts to death.
The box on the bike is a steel box filled with sand. The rider is wearing a Rucksack, too. This is made to get the weight of rider plus bike to just over 100 kilograms. Don´t know why they did not let a heavier rider do the test.
He rode down a steep narrow road and finally, after the descent flattened out accelerated to 40 mph and did a emergency brake. Unfortunately there was a cut between the testride and the picture of the melted rotor. At the end of the testride the rotor still had the small orange sticker on it. There was no orange sticker to be seen when they showed the melted rotor. Strange. I´m thinking that if a rotor gets so hot to melt the aluminum core then a small plastic sticker should melt, too – even when it´s sitting in the middle section.
Another Magazine, bike, did a similar test with the first MTB Ice-Tech Rotors some years ago.
Perhaps Shimano did not place enough commercials.
I´m using a lot of different brakes, cantilever, V, mechanical road rim, mechanical cyclocross disc and XTR Ice-Tech. All are fine to me.

K11 - 06/09/14 - 4:15pm

@alex. agree with last statement. it comes down to a combo of ride technique and the choosing the correct gear for the job.

Pete - 06/09/14 - 6:11pm

Out of this whole article….the thing I really wanted to see was a pic of the complete Bike!

Mike - 06/09/14 - 9:02pm

I have 622mm rotors on my bike.

KGr - 06/09/14 - 11:06pm

I destroyed a Reynolds rim from overheating coming down a steep mountain pass with plenty of asphalt expansion cracks. I’d rather keep the heat on dedicated disc rotors. If they have to be 160mm or larger, so be it.

Aaron - 06/10/14 - 3:14am

R785 shift/brake sets come stock installed with the older-style (SM-BH63 I believe) Shimano brake hose. Shimano reps claim that when testing it back to back with their newer BH90 hose (same as XT/XTR/ hose), the older style hose gave a more “road-like” brake feel (better modulation perhaps), so they supply it as the stock brake hose.

Apparently one of the primary reasons newer Shimano hydro brakes are so insanely strong is the redesigned BH90 hose. It is very stiff and delivers all the hydraulic fluid to the piston without losing power to flex/expansion in the hose.

If you’re looking for a bitier, more MTB-style stopping power and feel, my Shimano reps said you can easily swap in SM0BH90 hose instead. They told me that the power takes some definite getting used to, but I myself would prefer more braking power, and would run the BH90 hose.

Moby - 06/10/14 - 4:54am

@Aaron
I upgraded my custom TiCycles disc road bike from the Ultegra Di2 10speed/bb7s set up that I’d been running for just shy of 2 years to DA Di2 11 speed/R785 back in March. I’m running 160mm rotors from and 140mm rear. I guess I have the stock old style hose as I’m running what came with the R785. I have 3 months of 80+ miles a week in all conditions (PNW). I have no need for more power out of this system. Modulation and top end power both blow away the bb7s. Now, I don’t have a mtn background so I don’t know what an mtn hydro set up feels like. I just know that a 160mm front is overkill for me @167lbs.

Laurens - 06/10/14 - 8:20am

Tour magazine’s sister mag BIKE had a trashing test of the first IceTech mountainbike brakes back in the day as well. The verdict of their testing had nothing to do with real life experience, though. Possibly because no one will ever brake continuously for 10 miles – you’d better stop after half the distance (or even earlier) to loosen those cramps in your hands and lower arms.

It’s annoying to see that a magazine with such a huge circulation as Tour (and a well-educated staff consisting mostly of engineers) is continuing to apply test parameters that are not reflected in real life. Yes, you can test any part to destruction. No, it’s not necessarily relevant in real life conditions. Unless you’re a 200lbs rock climber who can squeeze a brake lever for more than 10mins continuously, that is.

Tom - 06/10/14 - 10:09am

Tyler, did your brake levers rattle like a bucket of bolts when you hit bumps? Mine sure did. Ended up having to remove the hood covers and glue a small piece of rubber onto the top of the brake lever, where it smacks into the hood’s cross pins. A very inelegant solution. Not at all Shimano-like, in my experience!

Tyler Benedict - 06/10/14 - 10:51am

Tom – yes, they did actually. Forgot to mention that. Resting a finger on the brake lever quiets them down, but it is pretty annoying.

Laurens – FWIW, both SRAM and Shimano’s road hydro levers are so easy to squeeze, I don’t imagine them causing hand cramps unless you’re overpowering the brakes. But I don’t think feather dragging for 10 minutes would cause muscle fatigue in most riders. Cable actuated discs, yes, absolutely…which is something I’ll elaborate on in a future post.

Matt - 06/10/14 - 4:37pm

At one point in my life I was 240lbs and from my experience coming down mountains, I can state that no caliper brake/pad/rim combo would survive what that tour video did to those rotors. With a standard caliper setup you not only have to contend with glazing your pads, but the heat soak build up can cause your tubes to blow. Thank god I am 160lbs now, because stopping is so much easier… not to mention going uphill.

KGr - 06/10/14 - 7:23pm

Laurens – depends on your real life situation. On my mountain bike, dropping 4700ft in 9 miles and over 100kg puts my typical Saturday not all that far off from one of the German magazine tests.

Haven’t melted my Ice Techs yet, but I’m using 180mm on a 29er. I’m very skeptical about Shimano’s “no weight limit” claim on the 140.

markus.gerat - 06/12/14 - 12:47am

german cycling magazine “tour magazin” should that those freeza rotors are melting the alloy core if they get to hot in hard brake conditions.that is really a pitty! because “bike magazin” showed this issue some years ago and shimano didnt react on that.

http://www.tour-magazin.de/technik/so_testet_tour/video-praxistest-scheibenbremsen/a30097.html

watch video (no german language needed to see and understand)

markus.gerat - 06/12/14 - 1:05am

sure german magazines do that. lol.
but: look what track the go by bike. this is not a very critical situation. i know much more sloping downhill streets in the mountains. and i dont want to crash because my rotors melt down.

but i think if you use 160 mm freeza rotors with a weight of 85 kilo / 187 pounds it will work.

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