joewein

Do disk brakes make sense on brevets?

While I'm generally happy with my existing bike for brevets, I never like the performance of its caliper rim brakes (Shimano 105) in the rain. Once it gets truly wet out there so water splashes onto the braking surfaces, even my wife's shopping bike with its rear drum brake will out-brake it.

So far I've been mostly lucky on brevets with rain, but last year I rode a 300 km where it rained continuously for the first half (luckily most of that was flat or uphill). On any long steep descent in the wet I start dreaming of disc brakes, even more so when riding in town (e.g. shopping) where there is more need for sudden stops in traffic. I hate it when it takes an unexpected long time before the brakes start kicking in as they first have to wipe the water off the rims. So far I don't have any experience with disk brakes except for some short distance riding on a friend's MTB.

Some people say front disc brakes aren't a good match for randonneuring bikes because they require stiff forks, which can make for a less comfortable ride. I have to say, I don't see many disc brakes bikes at brevets that I ride and I live in a rainy, mountainous country (Japan). A friend of mine here does regular 85 km commutes in any weather on his disc-equipped CX bike and he likes them, except for noise.

So what's your opinion? Are disk brakes worth the expense and weight? Compatible with comfort? Worth having on both wheels or only front or only rear? And if so, mechanical or hydraulic?

Phil MacFarlane

I have TRP HY/RD hydraulic brakes on two of my bikes. One bike is a carbon Volgai Liscio the other is a custom steel rando bike by Harvey Cycle Works.
all Volagi bikes have disk so I think they designed the fork with that in mind.
Harvey has an extra suport on the brake side of the fork.

I think the disks are much better that rim brakes. I was riding a 200k in the rain yesterday. It's nice to have brakes that work in the rain. When wet they do make noise when applied but just for a few seconds.

Go with hydraulic disks is my opinion.

RUSA 8400
Ancien
K- Hound
7x SR.

unterhausen

a conservatively-designed steel fork that accepts discs is a beast, no doubt about that. I feel like some of these issues are really overblown. A largish tire will make up for it for most people.

StephenH

They make sense, but surely aren't a requirement, either. There's pros and cons, use what you like to use, and if that's disks, great.

chriskmurray

One thing that is really nice with disc brakes if you ride in the wet often is you no longer have to worry about rim wear which can save a lot of money and hassle.

I personally have never been able to tell much of a difference in ride quality between a disc fork and a canti fork but I do tend to ride wider tires so that probably helps a fair bit.

thebulls

Hmm, I've ridden tens of thousands of miles with cantilever brakes on the tandem and have never had this problem. What kinds of pads are you using and what kind of rims? With either Koolstop salmon pads or Scott-Matthauser salmon pads, on aluminum rims, braking in the rain is definitely not quite as good as in the dry, but nothing like as bad as your experience.

I have disc brakes on my winter snow bike and they have been just fine. I had always assumed that disk brakes are basically superior in rain until reading this article: Bright future for disc brakes fades briefly under a coating of Verona mud - VeloNews.com

Basically, in bicycle-cross conditions with thin mud, hard braking on downhills wore out the disk pads in approximately two minutes of service. While that might seem of only academic interest for randonneurs, I think it might actually have practical implications. PBP in 2007 had plenty of mud on the roads that got flung up and all over people's bikes, particularly those who were fender-free. Four days of hard braking on downhills might be the equivalent of two minutes in bicycle-cross conditions. I'd be interested to know if anyone who rode PBP in 2007 can report on their actual experience.

Nick

unterhausen

Nick, I'm not sure that was mud.

On a more serious note, I think the mud conditions that caused disc failures were significantly worse than you would ever see on a road ride. That was the kind of mud where the CX guys switch bikes every lap.

plodderslusk

In october I was near Nice for a fortnight and did a lot of road riding with my Ultegra-disc CX bike with 28 mm Four season tires. Felt OK fast on the climbs and flats and really great going downhill. The stiff CF fork with discs felt very safe and I had great control of the bike in the corners. Especially a hilly brevet would be a good place for discs.

Carbonfiberboy 

I think a major thing to think about for brevets is field maintenance. Basically you shouldn't have anything that could go wrong that you can't fix. I think rim brakes are the simplest thing.

I know what you mean about braking in the wet. I just allow for it and try not to get myself in a situation where it's going to be an issue. More braking force = more likely to skid, so for me rim brakes have been fine. I do have to replace a rim about every 6000 miles on our tandem. I regard it as a cost of doing business and replace the rim myself. It doesn't sound like discs are much better in that regard. On my single which I've used for wet brevets I have Open Pro Ceramic rims. They will probably last longer than I will. Too bad Mavic doesn't make them anymore, but I think other ceramic rims are available through Thorn. Ceramic rims are the real ticket for rain riding.

Of course pads are a big deal. The Koolstop Orange are good. The Swisstop blue are probably better. I've been using Swissstop GHP2 pads will good success for the V-brakes on our tandem.

dwmckee

Both are fine and it just comes down to personal preference. I have become a disc man with TRP Hy/Rds like Phil and I ain't lookin' back... I love the much finer lever feel and low force needed on the levers when my hands are tired and cold.

austex

[.....]
Basically, in bicycle-cross conditions with thin mud, hard braking on downhills wore out the disk pads in approximately two minutes of service. [...]

Use of "solid", non-perforated rotors in muddy conditions appears to mitigate pad wear in disc brakes. Ref. Velonews and/or Cyclingnews.

thebulls

Yes, theoretically, based on advice from motorcycle racers. In the article I read, Velonews was not able to find a source for solid bicycle rotors.

unterhausen

I don't think it's generally a problem. I have ridden my disc equipped bike on rain-soaked dirt roads without issue. You really have to have some mud accumulation before it causes problems, a little splatter isn't going to be a problem

StephenH

I've got about 41,000 miles on my single bike and about 19,000 miles on the tandem. I've had problems I couldn't fix, but it wasn't brakes (Had a hub go out, had a bottom bracket go out, have seen a bottom bracket break...and don't know anyone that carries fixes for those with them!) I have seen rim brakes that couldn't be fixed on the ride, but that was due to a minor collision.

On the "much better" comment, I assume you mean you'd have to swap discs out as regular as rims. I have no idea on the rim life. But I think the tandem is on its original disks, and the single bike is on maybe the second set of disks. Anyway, the disks last a long time, it's the pads that wear out. And swapping disks just involves unbolting one and bolting the, it's not a wheel-building operation. Come to think of it, swapping disks is something you could do beside the road, although I'm not aware of anyone that carries spares.

Carbonfiberboy 

I've never ridden discs, so I have to judge from the comments of others. There certainly has been a lot of talk about problems with discs on the tandem forum. And of course there's the guy with the runaway single bike. A tandem team I ride with lost their front brake on a descent, smoked the rear disc before they could slow down much, and went off the road. Not hurt. Then there's the famous tandem group descent of Ventoux where every disc equipped bike damaged at least one disc brake. Every rim brake bike made it without damage.

One seldom sees whole threads about rim brake problems, though there was one recently on the 41. One of my riding buddies, who can buy whatever he wants, had a randonneuring bike built with discs. He only rode it on a couple of brevets before abandoning it for that purpose. He said it was too much trouble. Too fiddly to get the pads not to rub, warping the discs, this and that. Maybe there's a much steeper learning curve than with rims, which are quite simple. He said the very good thing was that he broke a spoke on one of those brevets and didn't have to do anything, just wound it around a neighboring spoke and finished the ride.

StephenH

It might help to note that in my area, you don't need brakes on most hills, so the brake heating/rim heating isn't usually an issue. I haven't done any big mountain descents with them or anything.
I've seen one case, I think, of an overheated rim causing a DNF, but it's not the norm here, either.
I've seen one case of heavy rain where a couple of riders found themselves descending without brakes (rim brakes, that is).
Most of my co-riders use rim brakes, so I don't hear much back about disk brake issues.
With the broken-spoke issue, that is correct, you can break a couple of spokes and still ride it in. That's good, but seems like I've also read that disk brakes put more stress on spokes, so maybe you're more likely to break them in the first place, too.
On the fiddly/adjustment issue, that's variable. My tandem has BB7 brakes, my single bike has BB5 brakes. The BB5 get a lot more fiddly when the pads start getting worn- they're better on new pads. You have to start adjusting them more often when they get worn. No experience with other brands or types.

downtube42

I wish I'd gone with disc brakes on my recent rando purchase. Steep downhill + sharp curve + metal bridge decking, on a rainy day... twice in 2014. I didn't crash, but yowsa! My old bike had V-brakes; moving to sidepulls on the new bike was a step in the wrong direction.

bmike

my next rando bike, should i build one, will be disc with rohloff.
love the discs on my fargo, and now my krampus. running bb7s (on the fargo, krampus, pugsley).
have done some crazy loaded mountain descents in the mud and wet and cold and have not had an issue.
i can't see how it would be a problem on a road bike - less weight (unless loaded touring), roads typically allow for higher speed and more time to react (compared to trail riding), etc.

tandems - that opens up all sorts of problems - weight, heat, cable runs (if mechanical), etc. etc. i can totally see how there would be issues / failures. especially if folks aren't running a drag brake and just relying on discs.

Six jours

I'm using the same brakes on my gravel/monstercross bike and find them very powerful but somewhat hard to modulate. They are fine for their purpose, but I wouldn't be happy with them on a road bike. Modulation is supposed to be the big selling point of disks - especially hydraulic disks - but I have never found that to be the case. I have always had a harder time selecting "just the right" amount of braking with hydraulic disks and find good cantilevers much easier to use. Maybe I'm using too many fingers...

I suppose if someone is looking for very low effort braking and doesn't mind the extra weight and expense, hydraulic disks are the way to go. Personally, I would never use them on a rando bike. I think cantilevers with Kool Stop salmons are just about perfect for that application.

joewein

Thanks for all the great feedback so far, with many different viewpoints! It has been most helpful.

My immediate action item will be getting some Kool Stop salmon pads (cartridge inserts for Shimano rim brakes) for my existing bike. I've already given the rims a good cleaning.

I had already heard about how it's easier to deal with broken spokes with disc brakes, and even with damaged tyres. When you don't have brake surfaces to worry about, you can use electrical tape, zip ties, etc. for emergency tyre repairs. Having said that, I haven't had one broken spoke or major tyre failure in 25,000 km so far (I've only had simple punctures [3x] and broken RD cables [2x]).

Avid BB7 seem to get good reviews and I'll also check out the TRP HY/RD hydraulic brakes. I'm looking at reviews of the Soma Double Cross Disc as one potential candidate for building a brevet disc brake bike from a frame set, perhaps as a 650B.