Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.
MAUI, Hawaii (VN) — When Shimano sneezes, the industry as a whole holds out a tissue. To fall out of the company’s graces would be perilous indeed; within the cycling industry, it has no real match. It’s more than twice the size of its nearest competitor, SRAM, and has for well over a decade been the undisputed king of components. Nothing about the machines we love changes dramatically without Shimano’s blessing.
This month, that blessing was applied to the road disc brake. VeloNews was on hand in Maui, Hawaii, for the North American launch, and caught up with the senior product manager behind the new R785 disc system, Dave Lawrence, to find out what the largest component brand on the planet has to say about drop bar disc brakes.
VeloNews: What set off development?
Dave Lawrence: The understanding that (discs) were going to be coming in the future. At first we came out with a mechanical road disc at a lower price point; something for commuters and bikes like that. It started at the very low end, basically just a mechanical disc with a drop bar lever compatible stroke, at least five years ago. It was all Tiagra level. People were starting to play around with running them on some ’cross bikes and commuters.
At the time, the European pros weren’t the ones clamoring for it as much. So that’s as far as we went for a bit. But development on the hydraulic version started about the same time, five years ago.
VN: Who are these new discs for?
DL: First and foremost is, anyone who is looking for all-weather braking. That’s one of the distinct advantages of a disc versus a rim system. The easy one is the ’cross guys. It’s legal, they race in crappy conditions. And then, from there, it’s people who are looking for something with more confidence.
The linear progression of the braking is so predictable. You start to feel the brakes coming on sooner, and you get a very consistent feel all the way through the stroke. And I think that is really confidence inspiring. I saw it in the elite riders, they go into the corners braking later, feeling very confident in the consistency. That lends itself well to the average rider, someone who is less confident.
We’re looking into the idea that discs will be legal in non-UCI road races in the U.S. That could change things here, if suddenly you can race them in a crit. What does that do? Well, it brings up a host of things that we thought were farther down the line. We’re working on that now.
VN: When will we hit a tipping point towards road discs, if ever?
DL: I think we saw, based on our mountain bike experience, the tipping point was when we could tell people there was no weight penalty. That was the holdup for a lot of XC racers. “Well, I feel like I can stop well enough,” they would say.
I think it was with our first XTR brakeset. We could finally tell racers, “When you pull the bosses off the frame, this will be the same weight as your v-brake version bike.” That took that one big objection away. But to get there you have to look at the frame, the wheelset — when all those three things come together, you can get to a tipping point.
I think it’s still a few years away. There needs to be some coordination. But there are tons of benefits available now for riders now.
VN: When will we get to that point, where the weight increase is negligible as it is on cross-country bike?
DL: That I don’t know. It could be something in the frame that is the tipping point. What I think would also change things is people’s perceptions. Once there are enough frames and enough bikes equipped with disc brakes out there, does the objection based on weight go away? So will this happen sooner because (consumers) see the value in the technology over the weight penalty? Today most are basing it on little or no experience on the product, but I saw some attitudes change over the weekend (At Shimano’s product launch in Hawaii -Ed.). Some guys came in skeptics and left with a very different attitude.
How quickly people adapt, that will play a big part. If USA Cycling allows them in racing, that accelerates things even more.
VN: What’s an acceptable weight penalty today?
DL: As (bikes) move up in price points, it’s more important. When you’re talking about a commuter, people are less concerned. But as you’re talking about a nice carbon endurance bike, it’s a bigger deal.
That’s what we’re all waiting for. We’re trying to get as much feedback as possible. Ultimately the consumer is going to decide how quickly things move. We need to give them more choices, a nice selection. We’re always working on new product. It’s continually improving.
VN: How many iterations of the R785 did you go through during development?
DL: We’re in the range of three-to-four different versions of the levers. Tough to say because some things are just small changes. The biggest change was between version 2 and 3. Lever feel was the big thing. The first versions were very much on/off feeling. It was all about tuning the lever for road use.
In the early tests, romping around in the woods in Japan, we were like, “ok will this be applicable?” The ’cross application was easy, absolutely. I can control my bike with less effort, that’s obvious. After that first step it was all about the feeling. That very linear feeling was tough. How do you get it to feel like a road brake but get the advantages of a hydraulic system? We spent a long time on that.
VN: What about failures? Poor bleeding could certainly result in failure.
DL: The first line of defense for us is that you should let a pro mechanic work on your brakes. The brakes that come on the complete bikes are pre-bled at the factory, and those have a very sophisticated system for the bleeding process.
The way we designed the actual product, it bleeds much easier than the previous system because it’s all a one-way bleed. More bubbles would get trapped in the old calipers; now they push right out.
The final issue here is heat management with a smaller rotor size. When we brought the system down to a 140-size rotor, to get the road look and feel, heat was the concern. That’s when the ICETech technologies come into play.
For heat management there is no weight restriction if you use the Freeza rotor and ICETech pads. There’s usage restriction: no tandems and such. But as far as power, if you feel like you need more bite then look at a 160 for the front, and if you need even more look to a 160 in the rear. Riders can decide what kind of feel they want.
VN: What is the boiling point of your hydraulic fluid? And how hot did the rotors get in your testing?
DL: When we did the test on Palomar (Mountain in California) and then in Italy, the highest rotor temperature was less than 300 degrees Celsius. The boiling point of the fluid is 280C, but of course the fluid will never get as hot as the rotor. There’s a lot in between the two. Ceramic pistons, which we use on all our mountain brakes, are a great insulator. We didn’t change the pads; we use all the same pads as the mountain.
VN: How do you deal with the wheel swap issue?
DL: I think that’s going to be a focus for the future, but for now I think people are thinking less about that since it’s not a UCI-level product yet.
If all of a sudden USA Cycling says,” Go ahead, race,” then that changes things. I think everyone thinks that’s still a few years out, because on the ’cross side most guys are just swapping bikes, at least at the elite level.
It’s going to be tough, because people will be adjusting their calipers to rotors that aren’t totally true. (The brakes) are being set up for that rotor on that bike. You always have variance. There is adjustability built into that caliper for that very reason. The reason there’s so much adjustability in the calipers is because even though you put a (rotor and mount placement) specification out there you understand that there will be variance.
Is it possible to get everyone dialed in to an exact specification every time? Or will it have to be manufacturer-specific wheelsets? I hope not. It’s something that will have to be studied deeper.
VN: What about aerodynamics?
DL: I’ve heard mixed data, from different bike companies that have done testing. It doesn’t feel definitive yet. I’ve heard things like the rotor on the wheel doesn’t add much (drag), but adding spokes does add more drag.
VN: So are we never going back? Will consumers latch on to hydraulic discs on the road?
DL: What I’ve seen is that it depends where people come from. If they come from a mountain background, or a commuter background, they are more open to it. Folks that are pure roadies, who can already handle a bike pretty well, they don’t see the need right now. There are still obstacles, like frame options and wheel options. But I think we’ll get there.
Editor’s Note: Shimano provided VeloNews and other outlets travel and three nights’ accommodations in Maui for its recent product launch.