2013 Interbike, Part 8


I can say with some certainty that my favorite product introduced at this year’s Interbike show that I actually got to ride, as opposed to just staring at, was the new Shimano road hydraulic disc brakes. It’s become popular for people attending the show to say, “You know, I didn’t see anything that wowed me.” That’s been the cool kid thing to say ever since Americans decided that Eurobike was the cool show. I think it’s damned cynical.

This brake system wowed me. I don’t see any point in lying. Two years ago I was arguing against disc brakes on road bikes as causing more problems than they solve. The thing is, I’m not an engineer, especially not a motivated one, but I understand the thrill of problem solving, and that’s mostly what engineering is.


For those of you who have been pulling on jerseys since they were wool, you’ll recall that Colnago was once the place to look for all the most forward-thinking ideas, even if some of them were crazier than Hunter Thompson at Burning Man. It was nice to see the storied Italian brand embrace disc brake tabs and internal routing for the hydraulic brake lines, though I could hear people crying foul to see Shimano parts on the Italian legend. That didn’t bother me, but what did make me chuckle was seeing such forward-looking technology on a bike that was glued together.


The brake set is non-series, which is to say that they are neither Dura-Ace nor Ultegra. That gives product managers the opportunity to use this brake with either group without it looking wholly out of place.

The brakes can be used with either a 140mm or 160mm rotor. The Colnago I rode was equipped with 140mm rotors. There’s been a concern within the industry about using 140mm rotors and heat buildup. You’ll notice that the rotors above feature two different colors. The outer ring of material, the portion of the rotor the pads actually grab is, of course, steel, but that inner ring is aluminum which, by virtue of the fact that aluminum isn’t very dense, allows for speedy heat dissipation.



The brakes themselves also feature fins to help them function as heat sinks.  Shimano went to a number of far-flung locations for product testing, including the Stelvio Pass (at this point it seems like you can’t claim to have tested a brake system until you’ve been to the Stelvio), so when they say that heat buildup won’t be a problem with a 140mm rotor, we’ve got some reason to take them at their word.



This detail of the rotor shows the pairing of steel and aluminum to increase heat dissipation.



The lever has a couple of advantages over SRAM’s lever. First, of course, are the improved ergonomics. Shimano went with the Di2 electronic shifting so they could gain valuable space in the lever for the hydraulic master cylinder, which is why the lever looks big but not tumescent. The lever also allows for reach adjustment as well as throw or free-stroke, which is how far the lever travels before the pads engage. These are two important adjustments that help keep the system feeling as much like a traditional rim brake system as possible. Because Shimano has made hydraulic systems for a variety of applications, from cross country to downhill, they were able to select components to increase modulation without compromising power.

My experience in limited riding on the system was impressive. With a 140mm rotor, power was on a par with rim brake systems. Modulation was terrific and felt more easily controlled than with some brakes I’ve used.



I’ve been vocal in my opposition to disc brakes. I haven’t seen the need. The maintenance is more complicated, the system is heavier, the aerodynamics compromised and the increased demand in frame strength changes the flex in the frame. I still think all those issues are, well, still issues. However, one criticism that can’t be leveled at the brakes is that they don’t work. They absolutely do and it may be that with some experience riders using them will find greater control thanks to them.

Stay tuned.

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  1. Anthony

    On mountain bikes I can (and often do) ride without suspension, gears, tubeless tires, dropper seatpost… I could NEVER go back to rim brakes. Hydraulic discs are so superior in terms of feel, power and modulation. Now that hydraulic discs are making it to the mainstream road I’m very excited to try them out.

  2. Ransom

    I dig the idea. This seems most of all like an excellent way to stop mucking about with what kinda look like half-answers to braking carbon rims.

    What I am curious about, given the ever-expanding emphasis on aero, is to what extent there’s a penalty for needing a front wheel laced to transmit torque, and with enough spokes to do so; a disc brake makes the front wheel capable of consistently generating more torque between hub and rim than the rear, as opposed to the usual “none”.

  3. cash

    What impact will this have on wheel design? I can’t see how a hydraulic disc will play nice with a wheel like a Zipp 303 or similar without some major accommodations.

    That said, i run XTR brakes on my mountain bike. Superlative is not a strong enough word for how good they are. I have Avid mechanical on my cross bike and they are good, but not great (but certainly better than cross cantis).

    Pretty stoked to see how road disc evolves. For now, I’m going to stick with what I’ve got (DA9000 rim brakes … which are sublime).

    1. Author

      Anthony: Interesting way to frame the advance. Thanks for sharing that.

      Ransom, Cash: Aerodynamic losses due to more spokes, the presence of the disc and a bigger hub are all issues that will need to be addressed. The thing is, when I talk to engineers and product managers about aero issues they all reduce it to an engineering issue. Put another way, it’s just math, at least, to them. ENVE and Roval (Specialized) have already introduced hubs for discs. We will see some losses in aerodynamics in the short term, but I’m told that there will be opportunities to improve aerodynamics once the need for a braking surface has been eliminated.

  4. Sam

    Another way to frame the advance is to look at the cable actuated, rim friction brake as the most antiquated component of the bicycle. Assuming the advanced technology elsewhere, the brakes deserve the same treatment. The bike is always evolving, do we actually bemoan the departure of six speed friction shifting or single pivot brake calipers, with their simplicity and easy of maintenance?

  5. Hautacam

    Extra points for “tumescent” and the Hup United jersey in the pic. Looking forward to an update when you or Robot or somebody has put a few hundred miles worth of saddle-time with these brakes under less-than ideal conditions (rain, gravel, sand, muck, etc.).

    1. Author

      Sam: When you talk to an engineer you’ll sometimes hear startling observations like, ‘Well, we’ve been using disc brakes all along. We were just getting double-duty out of the wheel.’ Insights offered have included that a rim is a pretty fantastic heat sink because of its enormous diameter and that brake force doesn’t have to be that high due to the leverage the wheel offers. Looked at another way, we stumbled onto a genius design a very long time ago.

      Hautacam: I’ll be getting on a SRAM-equipped bike very shortly.

      Jeff B: Correct. We had a very fun ride.

  6. dave

    I’d argue that modulation is orders of magnitude more important on dirt than on road.

    Road descending is all about entering the corner at the correct speed, usually a good descender only touches the brakes in a corner in an emergency.

    Which isn’t to say that the extra modulation won’t make riding more pleasurable, but completely unlike MTB I doubt very much that it will make you faster downhill, which for most people is the point.

  7. Ransom

    @dave; I’d have to argue “yes and no”… That is, faster is *supposed* to be the point, and is the stated raison d’etre for most of this really nice equipment we spend so much time and attention on.

    That said, an awful lot of it is bought and ridden by slowpokes like me (or actual fast people) who enjoy the tactile improvements of better equipment. A lot of the joy of cycling comes from how it feels, and modulation would seem to fall under that heading.

    It certainly is harder to rationalize a sea change in complexity and expense because “it feels a bit better”, though, I have to admit…

  8. Hautacam

    @ Padraig — all right! Give it some extra rainy-day and bad-road punishment (er, “evaluation”) for those of us up here in the wet Pacific NW. I

    @ JeffB — Always glad to see my Hup brother Andrew Yee in front of the camera! I’ll hand up your $1 at the next CX race.

  9. DaveO

    The cycling industry has discovered, late I might add, what the fashion industry always knew: In order to separate customers from their money you have to convince them last year is bad and this year is good.

    Rim brakes have been around forever because they work, they have few points of failure and can be fixed easily and cheaply. I wonder what people do with their road bikes that existing brakes can’t handle? It also begs the question, if your current brakes can’t handle it why are you doing it?

    Engineers love complexity but like the triangle, the column and circle there is virtue and strength in simplicity.

  10. Malcolm -

    DaveO: Engineers love complexity but like the triangle, the column and circle there is virtue and strength in simplicity.

    And beauty!

    Im with cash…Dura Ace 9000 is all I need too. The mountain bike and the road bike are two different tools.

  11. Robo

    A wise man once told me: “You have to have good brakes to go fast”.

    @Dave: modulation is incredibly important, particularly when riding in a pack. This is part of the reason why I agree with Cash & Malcolm – DA9000 calipers are far superior to even DA7900. They allow me to brake smoothly without setting off a chain-reaction of brake grabbing behind me.

    To me, the most exciting potential of road discs is the ability to run carbon rims without having to compromise on braking performance. If I can ride a lighter, more aero carbon rim, the benefits will more than make up for the additional weight and loss of aerodynamics at the hub/caliper. And it’s not as if rim calipers are all that aero – why else would every manufacturer be trying to bury them inside the fork on their latest aero race bikes?

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