Monday, April 25, 2016

Disc Brakes for Road Bikes?


There has been a debate raging over whether or not to allow hydraulic disc brakes in professional road racing. (Yes, bike race fans can get all heated up over just about anything.) I never much cared about this issue, and neither should you, really. That said, current events—first the decision to allow these brakes, then a gnarly injury, and then a decision to ban them again—are making it hard to stay on the fence. You don’t want to be the cycling equivalent of an undecided voter, do you? Read on for new ways to argue about this, whether it’s because a) you care, or b) you like to provoke people.

What’s good about disc brakes

First of all, let’s not pretend there’s any clear need to replace the caliper brakes on road bikes. I weigh more than 90% of the riders in the World Tour peloton, and I can descend a 20-percent grade with one finger on each lever of my caliper brakes. But that doesn’t mean disc brakes don’t have advantages.

First of all, they let you ride wheels that aren’t very true. Now, this isn’t a huge deal, because we all like our wheels true anyway, and no rider worth his salt keeps his brakes super-tight. To my mind, having super-tight brakes is like wearing a belt and suspenders at the same time, perhaps over an elastic waistband. You can safely run your caliper brakes really loose. This is actually better because your grip is stronger when your fingers are less outstretched. Imagine a tennis ball the size of a softball: could you squeeze it as hard? Nope.

(When I was racing, my bike tended to flunk the pre-race tech inspection if I didn’t temporarily set my brakes tighter via the barrel adjusters. Once I got my inspection sticker I’d loosen them back up. And how many races did I crash in because I couldn’t brake hard enough? ZERO.)

Still, there are instances where it would be handy not to have to worry about a wobbly wheel rim rubbing on the brakes. Say you crash in a race, and you’re the so-called protected rider on Team Sky, but your teammates are nowhere to be found, and you’ve knocked your wheel out a fair bit: you’d be glad if there were no brake pads for the rim to hit. You can go pretty damn fast on a wobbly wheel if the brakes aren’t rubbing.

Then, there’s the practical matter of having to keep your wheels clean. I love having disc brakes on my mountain bike because I can have thick smear of mud all over my rim and it affects my braking not a whit. But does this benefit carry over to the road bike? Generally not. I will say that I once blew through two entire sets of brake pads in one rainy month. So disc brakes would be nice for wet climates—at least for us consumers. But racers? These guys have professional mechanics. They don’t have to worry about picking little metal flecks out of their pads and/or replacing them all the time.

Maintenance aside, do caliper brakes perform well enough in the rain? In a protracted e-mail debate among my bike club, one rider—whose road racing chops are well established—wrote, “There have only been a few times I wish I had road disc brakes. In the rain and while descending Trinity Rd, I honestly couldn’t grab enough brake. Trinity in the rain would be an absolute nightmare.” (Actually, I did once descend Trinity Grade in the rain, and though I don’t remember braking problems, that’s probably because I got so cold that day I probably did permanent damage to my brain.) Disc brakes do have the advantage in this realm … they’re really not affected by rain or mud.

Now, there’s one more significant benefit conferred by disc brakes: your rims won’t overheat. Overheating is a problem with carbon fiber rims, and is sufficiently prevalent that carbon rims are banned in Levi’s Granfondo, a local cyclosportif. (Here is one rider’s horror story.) Even if you’re a skilled enough rider to avoid this pitfall (i.e., you don’t need to brake that much), you do have to pay a lot of attention to what brake pads you use on carbon rims. I would guess that a fair number of World Tour mechanics are drunks, and that riders have crashed due to having the wrong pads installed. Is this a conspiracy theory? No, I’m suggesting haplessness, not evil intent. Is this a stretch? Yeah, I guess it is. But I’m just trying to give disc brakes a fair shake here.

What’s bad about disc brakes

Check out this photo:

This was Exhibit A in a debate among pro riders about the dangers of disc brakes, which have the reputation of being like blades in a crash situation. According to Cycling Weekly, the above photo was tweeted by a rider with the caption, “why we probs don’t need disc brakes.” The problem with this tweet, beyond the use of the silly non-word “probs,” is that the injury was caused by a good old fashioned chainring, not a disc brake.

The idea of discs being like blades resurfaced recently when pro racer Francisco Ventoso crashed in the Paris-Roubaix classic and cut his shin open very badly. “It was so bad you could see the tibia,” his directeur sportif said. Ventoso wrote an angry open letter calling for a ban on disc brakes, and shortly thereafter the Union Cycliste Internationale (UCI) did ban them, having decided there’s something to this “discs are blades” notion.

(Is the track record of disc brakes in road racing poor enough to warrant this ban? I don’t know, and I honestly can’t be bothered to research the matter. But disc brakes have been used in mountain biking for many years without causing enough injury to make the news. Mountain bikes have a long history of accepting innovations sooner than road bikes, often for no good reason. Consider the threadless fork steerer: this appeared on mountain bikes during the 1980s, but wasn’t widely adopted for road bikes until around 2000. This design is unequivocally superior to its predecessor in every way … why the delay?)

Another problem with disc brakes is that the rotors can get dangerously hot, as pointed out by no less a cycling authority than Eddy Merckx. (Can you burn yourself on a rim heated by caliper brakes? Yes, but probably not as easily.) On the plus side, getting cut by a red-hot brake disc, rather than a chainring, might have a silver lining: all that heat might just cauterize the wound. (Yes, I’m being facetious, to stave off boredom.)

Some contend that disc brakes are too powerful and cause riders to slow or stop too abruptly. This is nonsense. I have top-end Dura-Ace caliper brakes on my road bike, and their power is no easier to modulate than the lower-end Deore hydraulic disc brakes on my mountain bike. The big difference is that I ride the brakes a lot more on the mountain bike, and thanks to the hydraulics my hands don’t get as tired as they used to. That’s a real benefit, and I’d never go back to cantilevers (or “cantaloupe-squeezers” as we used to call them)—but I’m not yearning for disc brakes on my road bike. Road conditions are seldom so demanding as rocky, sometimes muddy single-track trails.

Do pro racers need better brakes?

Let’s assume, for the sake of argument, that disc brakes really do stop better, and really do solve real-world problems like braking in the rain and safely achieving minimum rim weight. Does that mean racers need them, or even ought to have them?

I’ve been following this sport for decades and it’s never seemed like a lot of crashes had to do with poor braking. Meanwhile, the bikes—and moreover the riders—are getting lighter all the time, which I think actually lessens the need for powerful brakes. (The physics is a bit complicated, but empirically speaking, heavy riders descend faster.)

My pet theory about the increase in crashes is that race radios are turning riders into mere drones, and directeur sportifs are always yelling at them to go to the front, so they’re all fighting to get up there without (apparently) deciding for themselves if it’s safe to do so. Also, I think doping helps racers get fast much more quickly—look at Chris Froome’s overnight transformation from a middling Continental rider to Tour de France champion—and their growth in skill can’t keep pace. (So far there’s no drug for improving bike handling.)

Meanwhile, there’s reason to believe that better brakes might lead to less careful riding. I’m thinking here of Malcolm Gladwell’s article “Blowup” in The New Yorker in which he describes an early trial of antilock brake systems (A.B.S.) in cars. A fleet of taxis in Munich was outfitted with A.B.S. and compared to a control group with regular brakes. Oddly, A.B.S. didn’t reduce the number of accidents, because many A.B.S.-equipped drivers became more reckless and took bigger risks. Gladwell explains, “As economists would say, [the cab drivers] ‘consumed’ the risk reduction, they didn’t save it.”

This effect could be more pronounced in bike races, because the racers have even more incentive than a taxi driver to “consume” risk reduction. After all, a few seconds on a descent could be the difference between winning and losing, whereas a cab driver shaving a few seconds here and there isn’t likely to make very much more money in a day.

Then there’s the matter of the riders’ opinion. Frankly, I have a reflexive aversion to riders being coddled by the UCI. Remember, in the early Tour de France, riders had to make all their own roadside repairs, which was pretty badass if you ask me. Reading Francisco Ventoso’s whiny letter, I didn’t come to admire the guy:
“All of this happens because the international riders’ association—the CPA—national riders’ associations, international and national feds, teams and, above all of them, OURSELVES, PROFESSIONAL RIDERS, are not doing anything.”
What is “all of this”? He hurt his leg on a disc. He contends that another rider was injured by a disc as well, but this hasn’t been corroborated. Disc brake injuries aren’t exactly an epidemic. So why is Ventoso sounding like a 1900s-era slaughterhouse worker who has seen half a dozen colleagues fall into the hopper and become sausage? Whatever happened to being stoic and shrugging it off? Whatever happened to riders using whatever equipment they were given and keeping their mouths shut? (Granted, most of them are, but the few exceptions rankle.)

Whom are bicycles for, anyway?

The worldwide bicycle industry is worth roughly $50 billion. It does not exist to serve pro bike racers. To some degree, these racers have jobs because they serve the bicycle industry. The pro peloton is like a giant laboratory for bicycle technology innovations, along with a way to market these innovative products (because after all, everybody wants what the pros ride). This isn’t a sport where the riders tell the industry what they need; it’s a sport where the industry figures out what it can probably sell, and uses the riders to help do it.

Electronic shifting is a perfect example. As a concept, it’s kind of nifty, but utterly needless—a solution looking for a problem. Actually, that’s not quite right. There is a problem: consumers need an excuse to replace their existing (perfectly good) stuff with new (perfectly good) stuff. This is what makes the economy go. The bicycle industry (like most industries) is constantly asking the question, “How can we improve this product sufficiently that people will buy it right away?”

From that perspective, it totally matters what ought to appeal to everyday cyclists. I would appreciate a braking system that allows me to use whatever fancy carbon rims I want, without needing to keep them clean or true. I don’t personally seek the pros’ seal of approval on what I buy—but so many riders do. And that, more than anything, is why electronic shifting is used in the pro peloton.

Speaking of which, Ventoso totally undermines his own argument when he (needlessly) writes about electronic shifting in his anti-disc manifesto:
“We could also talk about the revolution that has brought the electronic shifting. When it was first shown and used, we all were surprised and made early judgments: it’s not necessary, it might not work well, carrying batteries seems wrong, having to connect your bike to AC is bonkers… And now, we can’t imagine our bikes without it.”
Look at this whiner! If he’d had some safety-related excuse to get out of using electronic shifting systems, he’d have made it. And yet look what happened: the electronic shifting technology evolved, and/or he got used to it, and he now loves it and promotes it like a good little marketing foot soldier. With regard to disc brakes, I think he’d be a far more responsible professional if he provided feedback to the industry—“Uh, guys, these brakes are great but it’d be nice if they didn’t slice us up”—rather than trying to put the kibosh on the whole innovation.

Where do we go from here?

My final thought on this anti-disc issue is that there’s a widespread assumption being made that they’re intrinsically hazardous in a crash situation. Well, they don’t have to be. The current rotors are totally flat disks, so the edges are somewhat sharp compared to most bicycle parts (notable exceptions being chainring teeth, which are much sharper, and bladed spokes, which are copious and have a tendency to be part of a spinning wheel). A manufacturer could pretty easily curl the edge of the rotor around so that its profile, instead of resembling a lowercase L, would resemble a 9 (or more accurately the Hebrew letter ףּ). Perhaps this would be harder to do when the rotor isn’t perfectly round (frankly, I don’t know why so many of them have a wavy edge). In that instance, why not just run a nice bit of silicone rubber trim along that edge? Make it out of the same heat-resistant stuff “rubber” spatulas are made of. Secure it by making it wrap around the edge of the rotor on both sides, with some nice adhesive within.

(Yes, I realize neither of these proposed rotors would clear the brake pistons during wheel changes. The brake mechanism would need to be modified, too: put a quick-release mechanism in there that would move the pistons out of the way during wheel changes. This modification would be child’s play for the bicycle industry.)

Perhaps the inevitable resolution of this issue is best summed up by a stirring proclamation from René Takens, President of the Confederation of the European Bicycle Industry (CONEBI): “We will not allow technical innovation to be halted in its tracks by racers’ complaints. We will stand up to that handful of whiny little bitches in the peloton, and we will prevail.”

(No, of course he didn’t really say that. But maybe he should.)

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