How long before disc brakes are standard on road bikes?

[pliptrot]

Disc brakes are creeping in at the edges of road bike (read: competitive) markets, at the trendy end where people spend silly sums of money on bicycles. As normally happens in the world of consumption, this will spread and become the norm. So, the questions are: (1) are disc brakes a good idea for road (racing, touring amd pottering) bicycles?; and (2) when will they be the norm so we can reliably buy appropriate frames, wheels and so-on?

[RickH]

I'll jump in first and say - for me - that it can't come soon enough.

I bought a Circe Helios tandems around 2 years ago (mainly as a grandchildren transporter), my first bike with disks (Shimano cable) & it has me sold on them. The brakes always work (although they can squeal a bit in the wet) which is a good thing as the last 1/4 mile home is almost invariably a steep descent that hits 20%+ in places (unless I choose the alternative route which involves 1/2 mile ascent with similar gradients - and not one I generally relish particularly if I'm riding the tandem home solo!). I bought some spare pads as I didn't know how long the originals would last but they are still going strong.

Compare that to my road bike - I run Mavic Open Pro rims & DP brakes, replace the pads at least a couple of times a year & the rims about every 18 months or so. Admittedly I do more miles on the road bike but I'm sure it is primarily the grit & muck in winter on the aforementioned hill that kills the rims.

If possible I intend to have disks on all future bikes. (And if anyone wants to give me a Colnago C59 - even just for long term testing - then that is fine by me! )

Rick.

[[XAP]Bob]

They are marginally heavier than rim brakes, so I don't exepct them on the tour.

They require a stiffer fork, so they might not creep into tourers for a while.


I love them

[Brucey]

engineering-wise discs have always been a heavier solution, that (as also noted above) uses a stiffer fork.

Discs therefore make more sense on bikes where there is suspension and/or fat tyres, should comfort be an issue.

There is a legitimate performance argument in some cases too, but in road racing? Er, no. Here however if the rest of the bike can be made to otherwise be below the UCI weight limit and with reasonable durability, the question becomes 'why not discs then?'. [That this question is asked is (along with 'why not electronic shifting?') perhaps indicative that they might have run out of good ideas IMHO....]

If it (for any reason, good or bad) helps a manufacturer sell more bikes, they will do it.

It is, (apparently...) called 'progress'. When it makes the World a Better Place everybody is happy; when it offers no real benefit, causes as many problems as it solves, or worse, it is the evil side-effect of free market economics...

I own and use disc brakes on several bikes and I think they make a lot of sense on (say) MTBs. I've been on some tours where I may as well have been riding offroad (although I wasn't...) as far as rim wear goes; maybe there is an argument for their use here too.

I don't necessarily like the idea of disc brakes from another standpoint; the discs are rather easily bent. I've seen this happen often on MTBs, not just in crashes, but usually when the bike isn't being ridden. Touring bikes and road racing bikes are just as vulnerable to this kind of damage. The amount of run-out that is acceptable is smaller in relation to the disc diameter than (say) the runout on a wheel rim is usually; they are therefore arguably 'less tolerant'.

Oddly enough I don't necessarily rate disc brakes for commuting either; I think there is a very real danger that it will be soaking wet, raining, and I will need to pull up without warning. All the disc brakes I have owned and used to date are significantly affected on first wet application. At the worst I'd say that the stopping distance might be doubled. Obviously if the brake has been used once and isn't immediately wetted again, they are fine; its just that you cannot ensure this will be the case when commuting. Rim brakes are also affected, of course, but perhaps not so badly. I also think that disc calipers will be vulnerable to seizure under winter+ zero maintenance conditions, and furthermore I am sure that people will run out of brake pads and 'not notice'... Hub brakes with durable brake shoes are the best for this kind of duty, without doubt.

If disc brakes become popular for road racing bikes then we may well see them on 'leisure' bikes in greater numbers. If we get them as standard on 'touring' bikes it will probably be by 'an accident of component availability' as much as anything else.

Some cable discs are pretty good now, but on a solo bike the performance /weight/price equation is finely balanced. Often, a big difference between (say) an £800 bike and a £1000 bike is weight. I reckon you pay about £200/lb (or more) to shed weight around the '£1000 bike' region. For a long time adding discs has been a case of adding both cost and weight which is not an appealing combination in the absence of some other compelling advantage.

It may well be that hard-coated wheel rims are (if economies of scale are achieved ) a 'better' solution than discs for many bicycle brake applications. Whether market perception would be the same or not is quite another thing...

cheers

[Ayesha]

Marginally heavier????

The caliper with the mounting plate is as heavy, if not heavier than a stirup.
Then there is a steel disc and enlarged hub details, 6 steel screws and washers.

There's a pot of hydraulic fluid on the brake handle.

[meic]

All the disc brakes I have owned and used to date are significantly affected on first wet application. At the worst I'd say that the stopping distance might be doubled. Obviously if the brake has been used once and isn't immediately wetted again, they are fine; its just that you cannot ensure this will be the case when commuting. Rim brakes are also affected, of course, but perhaps not so badly.

I am really surprised that you say this. My experience is the exact opposite. For odd reasons I have a disc brake on the back of a bike and a cantilever brake on the front. I happened to be riding on a flooded road in a downpour and I was amazed at how near to instantly the disc brake did work. I could also compare it directly to the rim brake on the front and I think the disc on the back would have pulled me up before the front was biting.

[reohn2]

Yep they're heavier,my two disc braked bikes (Salsa Vaya,Kona DewDrop)weigh 28lb each,other touring bikes I've owned with canti's or V's weighed 26lb similarly equiped.
We also have a C/dale tandem with discs,which is the lightest tandem we've owned at 40lb.
All have Avid BB7 road calipers,I'm writing about these brakes in particular as I've no experience with any other types.
I run 160mm rotors on the solos and 203mm on the tandem.
The major plus is outright stopping power with superbe modulation,modulation V brake owners could only dream of and this kind of power comes from just one finger,yes they are that good even on the tandem.
I can't agree with Brucey about wet stopping power being reduced and since he first mentioned it a month or so ago I've been keeping an eye on mine,even once pouring water over the front disc whilst riding,to no avail mine stop just the same wet or dry though the front can squeal when damp.Not so V's canti's or dual pivots though I've found BBB techstops(D/P) and BBB Tristops(V's) reduce the wet "waiting time" to a minimum.
However I take the point regarding buckled discs,if a disc becomes out of true it would be a problem especially when touring,but the chances are slim IMHO.
The MTB world is a different world entirely.I ride rough stuff on my two solos and can see the pitfalls but rim brake pitfalls are greater IMHO.

......I don't necessarily like the idea of disc brakes from another standpoint; the discs are rather easily bent. I've seen this happen often on MTBs, not just in crashes, but usually when the bike isn't being ridden. Touring bikes and road racing bikes are just as vulnerable to this kind of damage........

minimising this is surely down to careful storage and parking,though I am constrantly amazed at the way some fork treat their bikes
With discs the front fork has to be beefier so wouldn't be as comfy as a road fork with narrow sub32mm tyres fitted,unless on billiard table tarmac but I run 35mm tyres without any comfort issues.
Front discs can't be mentioned without mentioning front wheel ejection risk,something that again isn't an issue for me as two bikes have well socketed dropouts and the third has forward facing dropouts. Though I'd admit a caliper fitted to the front of the fork leg would be a better solution.
Will they be fitted to road race bikes? I can't see it anytime soon,simply on compatability issues,Wiggo puncturing on discs and the Mavic nuetral car not having a discbraked wheel calipers are here for a long time yet in racing atleast.I can't see the Sportiv crowd riding anything other than what the big lads are riding so outside of MTB/'Cross racing,Trekking or touring bikes I can't see it happening for a while yet,if ever.

[reohn2]

There's a pot of hydraulic fluid on the brake handle.

Not on cable disc's there isn't

[philg]

I would be concerned that on skinny road tyres they would be too powerful if used carelessly.

If caliper brakes are OK for the pros descending an Alp at 90kph, then they'll do just fine for me - a solution in need of a problem IMHO.

[reohn2]

I would be concerned that on skinny road tyres they would be too powerful if used carelessly.

If caliper brakes are OK for the pros descending an Alp at 90kph, then they'll do just fine for me - a solution in need of a problem IMHO.

And in the wet?
And don't forget the pro's bike handling skills at those sorts of speeds would put ours to shame.
Not to mention their bikes are washed,inspected and maintained to a very high standard every day by highly skill mechanics
There's a world of difference between a pro rider and someone who rides for leisure even if their mileage is high.
Tandem anyone?

[andrewjoseph]

I've got BB7's on my tourer. This is my only road bike so it gets a lot of use.

I specced cable disks for this custom frame and fork because comparing the brakes on my previous boardman road bike and my mtb's, was like night and day.

disks win every time for me.

It's not about the stopping power, though I found that better on disks too. As others have said, it's the modulation, the controllability of the power that makes them a better choice for me.

I think they are a better choice for touring. On our recent end to end, my wife buckled her rear wheel. This would have caused big problems in rim brakes. We carried on riding for another week and I fixed it when we got home.

it may not be needed for a lot of people, just as full suspension mtb's are not needed for many people riding to the shops, many 'cyclists' don't know how to change to another gear on their 18 speed setup. but it's nice to have the option.

[philg]

And in the wet?

I'd prefer a controlled, not so rapid deceleration to a high speed skid.

And don't forget the pro's bike handling skills at those sorts of speeds would put ours to shame.

Agreed, but I don't travel at anything like those speeds (for that reason!)

Not to mention their bikes are washed,inspected and maintained to a very high standard every day by highly skill mechanics

Yours aren't?

[reohn2]

And in the wet?

I'd prefer a controlled, not so rapid deceleration to a high speed skid.

Modulation

Not to mention their bikes are washed,inspected and maintained to a very high standard every day by highly skill mechanics

Yours aren't?

But of course!

[RickH]

Disks also solve the, seemingly endlessly discussed, problem of how to get brakes to work better without any esoteric fiddling with heights of straddle wires, v-brake arm lengths and the perennial "will it have enough clearance over my mudguards?"

Rick.

[[XAP]Bob]

I agree with brucey that they best brakes for your low maint bike are hub brakes.

I've not experienced his problems in the wet.