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.