2014 Shimano Hydraulic Road Disc Brakes ride preview and tech details

Shimano gave us a short ride opportunity to test out their new hydraulic road brakes on the latest 11-speed Ultegra Di2 group. On the ride, we had access to Dave Lawrence, their road product manager, and questions and braking were done hard and fast. Here’s what we learned:

First off, our bikes were using preproduction units, so take all this with that minor caveat. They were quite polished and probably look exactly like what you’ll see at the end of the year when parts start shipping.

The calipers are based on XT mountain bike brakes. As in, they basically are XT mountain bike calipers. This let them get a group on the road without starting from scratch, and it let them take advantage of the finned IceTech pads and trickle down Freeza rotor design to maximize cooling. They’re so confident in the combination’s ability to shed heat that they’re spec’ing 140mm rotors for all. As long as you use both the finned pads and Freeza rotors, there’s no rider weight limit.

2014 Shimano Hydraulic Road Disc Brakes ride preview and tech details

They used their older brake hose that has a bit more flex, so it’s intentionally mushier than the current XT-level MTB hoses. So the on/off of the full engagement is less severe. That means you’re less likely to lock up the wheels unintentionally because it’s purposely lacking the bite of their trail brakes.

Because these are just the initial offering, it’s likely higher end units in the future could see a sleeker design with the hose running to the inside of the caliper.

2014 Shimano Hydraulic Road Disc Brakes ride preview and tech details

Like their mountain bike brakes, it’s a one-way full bleed. Push fluid in from the caliper and out the top of the shifter. It’s all lined up so gravity and rising air works in your favor. Just below the bleed port is the reach adjust, and below that you can see the silver ServoWave rollers. Unlike on mountain bikes where ServoWave changes the rate of pad movement, it’s used here to simply provide a consistent lever feel throughout the stroke.

All of these adjustments are accessed by removing the silver top cap.

2014 Shimano Hydraulic Road Disc Brakes ride preview and tech details

Free stroke adjustment is under the hiod on the inside and controls how much lever pull you have before the pads make contact with the rotor. Back the bolt out and the pads will make contact quicker. This could be the key adjustment to getting the direct braking feel most riders will likely want.

2014 Shimano Hydraulic Road Disc Brakes ride preview and tech details


First, the good: Hood ergonomics are every bit as comfortable and sleek as the normal mechanical parts. Lever feel is super smooth, and modulation of braking power was pretty good.

I say *pretty* good because there were some potential issues with these preproduction units that resulted in a lack of full, confident braking power.

The rear brake lever in particular moved through a lot of space -about 60% of its throw- before making pad contact, then needed plenty more pull before it started feeling powerful.

Shimano’s tech rep felt it and thought the hydro fluid might be a little low, hence the amount of pull before rear braking really kicked in. A fresh bleed might fix it. He said these units just came in and they were building up the bikes quickly in order to have them ready for us.

The next initial concern was a bit of prolonged retraction on the front. At the start of the ride we had a few fast descents into corners, which required hard and/or consistent braking. That, coupled with the 100° desert heat, might have built up enough heat to keep the pads slightly close to the rotor for a few seconds. When I let go of the lever, I could still hear the pad making contact, and the noise faded away as the pad retracted over the next 1-2 seconds.

Given Shimano’s confidence in the thermal management properties of the equipment, the more likely cause was simply that the new seals inside the caliper needed to break in so they’ll retract faster. That means the issue would disappear as the brakes wear in a bit. They say this happens in mountain bike brakes, too, you’re just less likely to hear it.

About the power: I was hoping for more. I’d sprint then grab as much brake as I could without skidding, and it took a little too long to reign in the speed or come to a complete stop. A lot of the possible issues and fixes mentioned above would probably remedy this, but personally, I think I’d prefer the power and feel of a 160mm rotor, at least on the front. I rode a 140mm rotor on the rear of my mountain bike for years before switching to a 160mm, and the difference in power/feel I experienced there is what I believe was needed here, too. Keep in mind, I’m 6’2″ and about 190lbs kitted up.

So, at the moment I’d err on the side of trusting Shimano’s experience in making some of the best mountain bike brakes available and say these issues will be resolved on production parts. Several other editors on the ride said they really liked them, so it could have just been my setup. But that raises some very important concerns about making sure the factory or bike shop also has to set things up properly.

I’ll finish with this: I’m very much looking forward to testing a production set on my own bike. With a 160mm rotor.

A few notes on integration of the hydraulic brakes into an existing Di2 system:

You can put these new Di2 hydro levers and brakes on an otherwise 10-speed Di2 e-tube setup. The rear derailleur communicates to the shifters to tell them how to function. You would just need to update the software in the battery to make it all play nice together.

You can also mix and match 11 speed Dura-Ace and Ultegra, which would let you add a wider range cassette to an otherwise DA system or just upgrade a few parts at a time.

2014 Shimano Hydraulic Road Disc Brakes ride preview and tech details


  1. I’m looking forward my set arriving for my cross bike – although it looks like the additional Di2 thermals are missing from the lever bodies for Di2 remote shifters.

  2. Too bad Shimano didn’t have more time to set things up better, but these look promising. On Satruday I descended from 10,500′ to 6,000′ on 8% grades in pounding rain. This was the first time I wish I had road disk brakes. I could brake ok, but not nearly as confidently as I can on my mountain bike with XTR brakes.

  3. Personally can’t wait for these. Would love a hydro-Di2 setup, and wouldn’t mind setting one up on a bike at the shop on the stand. Win-Win!

  4. oh my goodness those hoods are disgusting!!!!!!! who would ever ride with those!!!!!
    (I joke b/c some turd will comment on how odd they look compared to sram)…blah blah blah blah…quit complaining you “too hard to impress” segment of the cycling community… just ride the bike and enjoy it, turkeys!

  5. I rode these very briefly on flat ground and if anything thought they had more grab and power than I wanted – at least for 23cs on damp road and not sure but I think 160mm rotors. Anyway, great feel, hoods / levers look + feel good.

    Why the need for thru-axles though? Not sure I see the point on a road bike. Forward-slot on the fork is there by the look of it.

  6. I’ve descended so many mountains on carbon tubular rims, never felt that I need better brakes. This hyrdo stuff is also heavy. The marketing message is so much stronger than the need. I guess this another way to make people buy new bikes!







  8. Why, if shimano are bringing in journo’s to test their latest brake offering would they not bother to bleed/set up the brakes properly? Regardless of time constraints- i could understand the bar tape being scrappy or gears being a bit clunky with indexing, but when you’re show casing a new element of the group it should be working perfectly. A lot of people look to eb13/ib13 for info on new tech and saying the units have sticky calliper seals/ poor lever feel doesn’t inspire confidence. It won’t be the first time shimano brakes have had problems with faulty calliper seals- either leaking or sticky- but I reckon this sort of issue is going to be a lot scarier on a roady than an MTB.

  9. The complaints about weight were the same ones when disk brakes were launched for MTBs in the late 90s. I know I was there.

    Ultimately the UCI has a minimum weight that brands have consistently complained that they can beat safely so the weight can be pulled from somewhere else. As for the common guy not buying a 14 pound race rig, well, yes they will be slightly heavier than a rim brake deal and more costly too.

    I know this though. I don’t ride my MTB with rim brakes like I do the one with disks. I have a lot more faith in the disks despite the high quality rim brakes I have on the other MTB.

  10. I completely agree with Jack. Your showcasing brakes that don’t even work. It takes hardly any time to do a bleed, and make sure they are in top shape before you give it to a tester that will write reviews.

  11. hmm. I have to say I have one of the new Specialized Crux running SRAM Hydro-R disc brakes, and in the month I’ve been riding it, it’s night and day better than my prior generation Specialized ‘cross bike running TRP Euro-Mag cantis. It’s nice to be able to nuke it into a loose corner and not lock up and slide. I’ve run the old (bad) Avid first-gen taperbore brakes on my MTB – they made noise and had bleed / sticky piston problems, and the Hydro-R at least for now seem worlds better. In fact the whole bike is so much nicer to ride than my road bike that it’s been left hanging in the garage for weeks and I may just sell it altogether.

    Hope Shimano can get the bugs worked out of this system as I’d definitely like to see this become a road standard sooner than later. I do a lot of road riding in steep terrain on dodgy surfaces and the modulation and security of the disc system is a game changer.

  12. Funny how they couldn’t say “Give us another hour to get these dialed in…thanks”. I blame pushy journalists! Besides the Internet told me not so long ago that disc brakes weren’t going to work for road bikes anyway.

  13. Come on, we all know this is just a marketing ploy. New ideas are being pushed on us (and recalled) at an ever increasing rate. A great sale to the “I need a reason to buy a new bike market”. Discs have their place but a road bike is not it.

  14. The sad part is that as much as I would like to blame the bike industry for inventing solutions to nonexistent problems I can’t. They are in the business of moving product and as long as consumers keep buying into their marketing hype without question they will flood the market with whatever sells. Whether is the ugly ass aero road bikes/helmets, 11 Speed, electronic shifting, hydro road brakes, BB standards or whatever other crap they have come out with lately. Even if you add up all the benefit of everything listed the gains for the vast majority of cyclist buying into it wouldn’t even be measurable on any ride they do.

  15. @Jack

    Dont forget how much lighter rims can be made when they dont have to withstand the compressive forces of road brakes. It makes sense, it might not be for everyone, but Im sure people said the same thing about disc brakes when they came out for mtb.

  16. Tyler, you wrote about how it “took a little too long to reign in the speed.” A reign is a king’s or queen’s rule, as in “long may he reign.” I think you meant “rein in,” which is how one slows down a horse—with the reins.

    It’s a small point. Anyway, thanks for posting this piece.

  17. Yep. Rim brakes are fine.

    sort of the way steel rims were fine, steel forks were fine, solid tires were fine . . . we could all go back to walking and eliminate any and all changes in technology, but if that’s your goal then why the hell are you reading this site?

    Seriously. It’s one thing to stick to something because it offers true superiority in enough categories to list, but it’s quite another to resist a new standard just because you’re used to the old stuff and the maintenance headache that comes with it.

    Nobody should have to replace their wheels because wear from braking. I’m glad to see Shimano and Sram offer this solution to a very existent problem with road and ‘cross bikes.

  18. Even though I have no personal love for CX, ‘crossers everywhere must be rejoicing — cantilever brakes are horrible.

    I’m also guessing most who are hating on road disc are not also MTB riders. The benefits of disc in terms of modulation have been clear in MTB for years. This — not power — is the huge coup for road disc. I understand that most think there’s no problem with road calipers modulation — I wouldn’t either if I didn’t ride MTB discs. Hell, even the linear pull mini-V style brakes on my current aero road frame have ruined me on road caliper brakes. I never knew how herky-jerky my road calipers felt until I rode something different.

    Open your minds, and don’t knock it till you’ve tried it….

  19. @Ryan and @RM ahh yes, But Sram/rockshox/avid NEVER EVER needs recalls, cos their products are always perfect… …. Or they just make like an ostrich and chuck their heads in the sand.

  20. @Parker

    That’s a good thing, most cyclists on the internet will tell you they are already too fast as it is.

    Also, I don’t see how recent advances in cycling tech have made anything worse. You can still get retrogrouch stuff pretty easily if you want, unless you split the difference and want new tech Campy 7-speed shifters or something like that.

    Also also, for the last X years, I have never heard any road disc supporter say ‘It’s because I need more power’. Yet someone always comes out of the woodwork to complain ‘Whaddaya need more power for?’

  21. just wondering, but why the hose need to run on the inside of the caliper for a road bike. Its covered by the chain stay back there and makes that banjo bolt way easier to set up in tight chainstays.

    in other news, what can you tell me about those shimano branded wheels on that colnago whip?

  22. Wow, struck a soft spot there lol

    My Shimano Mechanicals have been nothing but poor in the performance department on my roubaix and their customer service on the replacement/recall has been shit. They are usually great, but they dropped the ball on this one.

  23. Shimano needs to put more focus on internal hubs. If they focused the amount of attention on that as they do on normal components, internal hubs would be the shit..

  24. Sitting on the fence re: carbon wheels. Discs solve the rim-braking problem. Can’t wait till these descend from the esoterica/”and-up” firmament to the “popularly priced” categories.

    Don’t want hydros on your bike? Don’t have them. Simple.

  25. If it takes anything to convince people who are fervently against the idea of hydraulic disc brakes on road bikes, just ride a MTB with quality V-brakes such as an XTR and another with quality hydro discs such as XTR. In the wet as well as in the dry.

    Just takes 5km of technical trials. Its not about the absolute braking power available anymore. Its about the absolute control and modulation of speed you get out of the system.

    You’ll think doubly hard about picking up that V-brake MTB for a ride again. Especially when the conditions are wet. It will be a very similar situation with road bikes once it gets to the masses.

    Remember some years back there were those guys who questioned why did we need dual-pivot brakes on road bikes ?? What happened there after ??

  26. I got to ride these this week also, and I was really happy with them even surprised they stopped as well as they did. And compared to the new Hydro SRAM’s or mechanical disc they are far superior. I should have a bike late November and share the details.

  27. “Jscriv – 09/21/13 – 10:41am
    Does anyone know if these are backwards compatible with Ultegra Di2 10sp?”

    Yes, talked with the tech and will work with all Di2 except dura ace 7970, basically anything with new e-tube. Derailleur dictates 10 or 11 speed not shifter, but you have to update system software.

  28. @Jscriv – yes, they’ll work with any e-tube rear derailleur, mentioned at the end of the post.

    @fleche – those are Shimano wheels, but they’re pretty base level items. They are Centerlock only. Just as the reps hinted that these calipers are just a way to get their proven tech into the road bike segment, the wheels were a quick way to have something to use with them. Expect higher end items on both fronts in the future…but maybe don’t hold your breath. In the meantime, there are a world of new high end options from a lot of wheel brands. Search “disc brake road” and scroll through the first three pages to see plenty of options introduced in the last six months, noting what’s on some of the bikes as well as the standalone wheel articles.

    @NXrider – Yep, Keywins. Check the review here.

  29. These will turn out to be amazing, a few generations down the road when all the bugs are thoroughly worked out. Is it a good reason to buy a new bike? probably not unless you were in the market anyway. Interesting point that some people complain about the additional weight…. climbing on a 13lb bike is awesome, descending on 13lb bike (with cork pads and carbon tubulars) not so much. climbing on a 14lb bike still pretty awesome, descending on a 14lb bike with hydraulic discs, think about it!

  30. I’m planing to invest some money on a low maintenance road bike for daily usage from home to work and other places and I think that the Alfine 11 with a Di2 system, hydraulic disk breaks and a belt transmission would be the perfect fit that money can buy for city traffic bicycle. What do you think about this idea ? I know that for the same amount of money I could buy a very good bicycle and I was wandering if it’s worth it.

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