cs1

According to Dave Moulton they are. https://davesbikeblog.squarespace.com...bicycle-design

I'm sure this will ignite a firestorm.

ahsposo 

jfmckenna

That's an interesting take on it. I always thought disk brakes would be great on a road bike. I really wish I had them on my cyclocross bike. The main advantage being muddy races of course but also your wheel can go way out of true and you can still ride it. Disk brakes are way more powerful and I could see them being useful in the mountains especially if you race on tubulars so that the rims won't heat up and melt the glue.

Grumpy McTrumpy

I can think of a few situations where a disc brake might be preferable:

1. mountain descents in hot weather
2. racing in the rain

However, I don't know how well they modulate so I cannot be sure.

BTW I have read his blog at times before and I don't always agree with his viewpoints.

CHAS

Have heard too many stories of rim brakes in summer rainstorms that are lousy going down passes in the Rockies.
Putting a Rawland together for climbing and descending paved and gravel mountains roads and trails.

gsteinb

They look cool.

teterider

I wish I could remember where I read an article about this recently.

It basically came down to this argument of what was needed for road disk brakes, and that if they had always been standard then the latest high-tec development in road bikes would actually be caliper brakes with the rim acting as the brake rotor.

All of the issues in that linked post though are true, and disc's simply are stupid for road bikes. It didn't mention that the one-sided braking force down low on the fork also necessitates a stronger fork.

They just look cool and high-tec which is why somebody did it.

Grumpy McTrumpy

albeit they are both "disc calipers" there are a couple of major differences between a rim brake and a disc brake though:

1. rotors have holes to allow collected water to be quickly shed.
2. disc brakes are metal-to-metal. (or ceramic/metal)
3. the heat buildup will not cause problems with the rim-tire interface.
4. rotors are solid. wheel rims are not.

however, I don't think disc brakes are going to be used much on road racing bikes. the weight penalty seems too high and rim brakes normally work really well anyway.

touring bikes however....

merlinextraligh

I don't get the disc brake on road bikes. Modern caliper brakes have plenty of stopping power, and are easily modualted. So what more do you need in a brake?

We use Dura Ace calipers on our tandem, and have been able to descend things like Hogpen, Brasstown, and the descents in Everest Challenge (with speed in the 60's) without incident.

If I was doing a steady diet of very long, steep descents, on a Tandem, or a loaded touring bike, I could see an advantage for keeping the rims cool, but even in the extreme situation of a tandem they're not necessary, and certainly not on a single bike.

AngryScientist 

the blog seems to just present the very obvious. i do happen to agree with his points, but others have stated the reasons why disc brakes on road bikes are unnecessary better.

FunkyStickman

If they work better in every condition, then the only reason to NOT use disks would be for weight. I don't give a rat's you-know-what about weight, so to me, there's no reason to avoid them. If you ride a tandem, there's no need for a secondary drum/band brake for descents, so they may actually save weight, not to mention disk-specific rims can be made lighter, too.

I'm sure there will be a few people who moan about dished front wheels, but MTB guys use 'em all the time. I'm actually considering building a 700C road bike with drum brakes and moustache bars, so you know... I'm kinda "different" that way.

Grumpy McTrumpy

modulation is a pretty important thing in racing.

Tulex

Maybe, but the majority of people on bikes don't race.

Phantoj

Discs are great if you are going to be riding in the rain a lot. They perform reliably when wet and stay clean. Discs on a wet-weather or all-weather commuter are the way to go.

However, IMO, the current road brake setup (Avid DB7 Road) is still a little half-baked -- the lever feel is too mushy and lever travel is too long. Discs would be better with an improved STI setup that pulled more brake cable, or hydraulic STI.

I sold my disc-road-bike (Giant OCR Touring) when I left Seattle, and I never ride in the rain anymore if I can help it.

merlinextraligh

Not sure however, that is a correct assumption. They definitely tend be noisy, finnicky to adjust, require the pads to be burned in correctly to get maximum stopping power, it's easy to bend the rotors, and it's harder to do a wheel change.

Also you'd have to have rotors installed on all your back up wheels. So there are a number of functional, non weight issues to be considered.

AngryScientist 

not only racing, group riding, riding in traffic or even just with friends to the coffee shop for a delicious espresso, being able to modulate speed is fairly critical to protecting your front wheel and preventing chaos. IMO

vantassell

I have some BB7's on the bike I commute on, here's my experiences.

Disks are very consistant. Whether it's raining, snowing, a hot mtn decent, or loaded with 40 lbs of comutting gear, my brakes are predictable and reliable. Nothing affects their modulation or feel.

When I commuted with regular caliper brakes, I couldn't not stop quick enough at some lights. If it was wet, I was in real trouble.

For regular road riding, you'll be hard pressed to need anything more than caliper rim brakes (assuming you don't have super cheap tektro plasticy calipers, and you have good pads). For more EXTREME things (yeah, because touring/commuting scream extreme) disk brakes work great.

I've never done cyclocross so I don't know, but things sure get muddy and your rotors would definitely stay cleaner than your rims. That seems like a no-brainer.

FunkyStickman

What are these "backup wheels" you speak of??
And as for being noisy, hard to adjust, and hard to get on/off, they're no worse than regular MTB V-brakes, which aren't that bad.
(EDIT: Yes, I know we're talking about road bikes, but just as a comparison, they're not that bad.)

bonz50

disc brakes are technically superior to rim brakes in every functionally conceivable way... the weight penalty if where road bikers will have grief about 'em... probably add about a pound over current rim brakes set ups... would also likely require some frame geometry changes in the read triangle to accommodate the mounts and clearance for the rotor... up front I'm not sure I'd want a carbon fork with disc brakes... though you could make a "hybrid" fork that has one carbon leg and one AL (for the caliper mounts)... you could probably engineer a fork properly for it though so that might not be a valid concern... in a perfect world though I think you could get by with only a front disc, that way it doesn't change the rear frame design, only a modular piece like the fork... would be interesting to see if someone tries to go this route some day on a roadie...

AngrySaki

Saying disc brakes being a bad idea on a road bike is the same as saying a seat bag is a bad idea on a road bike. You're not going to want it when road racing, but there's other non-race situations where it makes sense (depending on how you use your bike).

Grumpy McTrumpy

noise boy

FWIW, In an interview with Lance Armstrong last year after the Leadville race, his biggest suprise was the braking from the discs on his MTB, he thought they would be good for road bikes. Especially since all of the bikes have to ballasted up to the UCI minimums anyhow, so there isn't really any weight penalty. Obviously there are engineering isssues that he probably isn't aware of, but it is any interesting perspective from somebody who races.

echotraveler

aren't disc brakes a lot more complicated to deal with??? calipers seem much more straight forward....

bonz50

what's different about them really?? calipers pinch the rim versus pinching the rotor... only difference is location really...

Grumpy McTrumpy

facepalm