Disc brakes on road bikes - do bike firms know something we don't?

Chips Lovell

First of all we had the Colnago C59 Disc. Now at this year's Eurobike several other manufacturers, like Canyon and Time, have launched road bikes with disc brakes.

Disc brakes still aren't allowed by the UCI for road races. Only cyclocross.

Seems to make little sense to me to buy a high end bike that you can't even race on.

Do the bike firms know that a rule change is coming down the line? Or do they reckon there's enough of a market there from well heeled leisure riders?

Vladimir Kurtains

Vladimir Kurtains wrote: »

First of all we had the Colnago C59 Disc. Now at this year's Eurobike several other manufacturers, like Canyon and Time, have launched road bikes with disc brakes.

Disc brakes still aren't allowed by the UCI for road races. Only cyclocross.

Seems to make little sense to me to buy a high end bike that you can't even race on.

Do the bike firms know that a rule change is coming down the line? Or do they reckon there's enough of a market there from well heeled leisure riders?

Hopefully. Would be nice of the UCI to allow some technological progress.

It's a shame to have to throw out otherwise good wheels because the braking surface is worn. Hopefully discs would mean you could get more use out of expensive race wheels.

bogmanfan

Well heeled leisure cylists would be my guess. I know several guys with full carbon race machines who never race. Even in my club, the majority of members are not involved in racing at all. I know I'd go for disk brakes if I had the option.

Raam

I shudder to see the sliced fingers and burns from bunch crashes.

CardinalJ

Raam wrote: »

I shudder to see the sliced fingers and burns from bunch crashes.

It wouldn't be any worse than spokes I'd say.

Raam

CardinalJ wrote: »

It wouldn't be any worse than spokes I'd say.

I hope not. I made the mistake of touching one of my rotors after descending and some heavy braking. You don't make that mistake twice.

Lumen

Raam wrote: »

I shudder to see the sliced fingers and burns from bunch crashes.

Brakes don't get used much in the races I've been in, certainly not enough to make the discs hot.

As for sliced fingers, is that really likely? Discs aren't that sharp or protruding.

The elephants in the room are ride quality and handling under braking.

The "first ride" reports I've read suggest that in order to avoid the front end wandering all over the place under braking (and avoid fork snappage) you have to make the fork very stiff, and that results in a very harsh ride.

Attempt to fix the front end harshness with damping will then invite further criticisms of poor handling, sluggishness, crap feel when sprinting etc.

And all that is assuming they can sell people on having 32 spokes up front, dragging pads from mechanical discs or possible brake fade when hydraulic fluid boils.

(Apparently hydraulic discs suffer less from dragging pads because both calipers move in together, whereas on mechanical discs only one caliper moves)

Raam

Lumen wrote: »

As for sliced fingers, is that really likely? Discs aren't that sharp or protruding.

I'm afraid to search the internet for it. Will you do it?

Lumen

Raam wrote: »

I'm afraid to search the internet for it. Will you do it?

Holy jesus, I'm not doing that again.

droidus

Official Cut off your finger with Disc Brakes Thread:

http://www.pinkbike.com/forum/listcomments/?threadid=33845&pagenum=1

Chips Lovell

The other question is does anyone actually want disc brakes on their road bike?

Raam

Vladimir Kurtains wrote: »

The other question is does anyone actually want disc brakes on their road bike?

Not me.

Tenzor07

Lumen wrote: »

or possible brake fade when hydraulic fluid boils.

Would the fluid really heat to over 200 degrees on a bicycle?




Sure have a read: http://road.cc/content/news/54390-component-brands-want-uci-allow-disc-brakes-road-bikes

Lumen

Vladimir Kurtains wrote: »

The other question is does anyone actually want disc brakes on their road bike?

I want disc brakes on at least one one of my road bikes, but not on my race bike.

A problem is that selling expensive road bikes to Freds involves pandering to our absurd delusions, one of which is that we're doing basically the same thing as those guys in the Tour de France*. Whilst Cervelo's ridiculous head tubes and seat tube angles stretch the delusion to breaking point, we're still only an 18 degree stem swap away from pro-ness. Discs totally brake** the spell.

(*) My 6 y/o son asked me a couple of days ago why I wasn't riding the TdF this year. I told him I was too slow. He suggested I ride faster and do it next year.

(**) See what I did there.

Beasty

What's the benefit when racing? OK you may be able to stop slightly quicker if someone falls off in front of you, but when racing on the road brakes are generally used very sparingly (and carefully)

Raam

Beasty wrote: »

What's the benefit when racing? OK you may be able to stop slightly quicker if someone falls off in front of you, but when racing on the road brakes are generally used very sparingly (and carefully)

I suspect the only benefit is in the pocket of manufacturers.

Chips Lovell

Lumen wrote: »

A problem is that selling expensive road bikes to Freds involves pandering to our absurd delusions, one of which is that we're doing basically the same thing as those guys in the Tour de France*. Whilst Cervelo's ridiculous head tubes and seat tube angles stretch the delusion to breaking point, we're still only an 18 degree stem swap away from pro-ness. Discs totally brake** the spell.

Actually, I've been thinking of that recently and I'm wondering if the received wisdom (that bike companies are making frames for freds these days rather than pros) is wrong. This trend for having stupendous drop has only emerged recently. Prior to that, pros rode on geometries most dentists would have been happy with.

Probably the topic of a different thread.

Max_Charger

Beasty wrote: »

What's the benefit when racing?

Apparently to give suicidal squirrels an easy way out.

Lumen

Vladimir Kurtains wrote: »

Actually, I've been thinking of that recently and I'm wondering if the received wisdom (that bike companies are making frames for freds these days rather than pros) is wrong. This trend for having stupendous drop has only emerged recently. Prior to that, pros rode on geometries most dentists would have been happy with.

Probably the topic of a different thread.

If by "recently" you mean "since integrated shifters were invented", then the reason is probably that the pros ride on the hoods more often than they used to. Hence shallow drops compared to traditional bend bars.

DominoDub

Read this story early on in the year, when looking into maybe getting a Cyclocross Disc as an good all round bike, which I hope to do soon:o

http://www.bikerumor.com/2012/02/14/road-bike-disc-brakes-are-coming-but-will-they-work/

Lumen

DominoDub wrote: »

Read this story early on in the year, when looking into maybe getting a Cyclocross Disc as an good all round bike

I don't really think there's any such thing as a good all round bike.

The Specialized Crux Disc is a good example of a reasonably specified mainstream mechanical disc braked CX bike, and that costs about €2k, for which you could buy a good road bike and a good mountain bike, or a summer road bike and a winter road bike, or any other combination of two bikes each of which does one particular thing better than the Crux.

I still want one though (or something like it) even though I know it's stupid.

seamus

Beasty wrote: »

What's the benefit when racing? OK you may be able to stop slightly quicker if someone falls off in front of you, but when racing on the road brakes are generally used very sparingly (and carefully)

The perceived benefit may be less so what you can do with braking and moreso what you can do with your wheels when you don't need to account for the braking surface and the stresses involved in such.
It means you can do funky things with carbon fibre that would otherwise be risky. Spokeless monocoque carbon fibre wheel anyone?

There are fractional benefits with braking in terms of engage and release time and other minor things.

Triathlon is also becoming quite big, so there's a market there.

Lumen

seamus wrote: »

The perceived benefit may be less so what you can do with braking and moreso what you can do with your wheels when you don't need to account for the braking surface and the stresses involved in such

Moving the stresses from the rim to the hub creates more problems than it solves.

For clincher tyres, something like a Zipp carbon/alloy wheel is very difficult to improve upon in any way except weight, and yet a disc braked system is heavier.

For tubs, a deep section carbon tubular wheel is also extremely difficult to improve upon except perhaps in the area of braking modulation, and if that was such a big deal they'd just bond a metal brake track on to it (or use a composite alloy/carbon rim).