Disc Brakes for Road?

symo

So BR has run a feature that disc brakes are the future for road bikes, but are they? I cannot personally see the point in reducing weight to a road bike in order to add to rotating masses ( Not to mention the additional strengthening required at each fork mounting), to each wheel to impede acceleration. We are not reaching 60kmh on the flat and have to brake late into bends like motorcycles. Also the weight on hills is restrictive; plus watching Cancellara descend in the 2009 TdF on normal rim brakes at real speed and being in control means I am one of those who will more than likely never see the need for disc brakes on the road.

What do you all think?

andy46

While I think it will be a good idea, I don't think a lot of people will go for them.

Then again eBay may fill up with quite a few nice bike that aren't disc compatible!

Smokin Joe

They will happen.

Weight will not be an issue as the addition will be minimum and even on a fairly modest budget it is possible to build a bike that is under the UCI minimum. In any case wheel rims could also be made lighter and more aerodynamically profiled without the need for a braking surface, with the added bonus of having their working life extended multiple times.

All the arguments against disc brakes on bicycles were put forward when they first appeared on motorcycles, yet no one would touch a motorbike without discs now.

rolf_f

I expect it will be like electronic groupsets. Some people will take them up, some won't but the pros and cons work both ways. For some people there will be real benefits - for others less so.

Probably a good thing on commuter bikes but probably a more of a gimmick on weekend posh bikes. Your posh bike is mainly ridden on quieter roads, in the dry when the braking distances aren't actually that different (I have compared and contrasted!). Rims wearing out isn't really an issue on a bike ridden mainly in the dry - particularly given that most people on here probably like rim wear as an excuse to buy new wheels (that is if their rim gets anywhere near enough worn for this to be a legit excuse!). Aerodynamics is a bit of a nonsense for most of us as well. Give me a shallow rim anyway but I defy anyone here to be able to claim that Zipps latest profile has had the slightest impact on their performance outside of the posing arena. Reduced rim weight on the other hand seems useful though, if that bothered you, whether you'd be able to make most of those savings just by switching to tubs is another matter.

And, tbh, I like the simplicity of rim brakes and I hate the squeaky, rubbing and dragging of the disc brakes on my MTB.

GiantMike

Yes. They will become a road bike feature in the future. Mainly because the marketeers will convince us we need them. and bike mags will say they are brilliant because they are paid by advertisers.

Disk brakes on MTBs were an inevitable and welcome performance advantage and I woudln't want to go bck. But I rarely wish my Cylocross bike had better brakes (but I would like better traction in the mud) and I have never wished my road bike had better brakes.

Tom Butcher

I wouldn't mind trying a road bike with discs - until I'd ridden with them it's hard to judge either way. There are obvious advantages in terms of making rims lighter and longer lasting - and apparently we'll get better brake modulation - on the other hand the cheap discs on the MTB do tend to squeak occasionally and seem to need fettling every time I take the wheel out and put it back.

esspeebee

I can see the increased control being a large advantage on fast descents. I don't see them appearing on aero bikes any time soon, but for 'normal' road bikes I can't see why they wouldn't.

Weight on the hills certainly isn't an argument against them for pro riders, given the minimum weight limit that so many of them have to add ballast to meet.

Frank the tank

I can't see them taking off on the pro circuit but cross bikes more than likely and tourers also.

amaferanga

Carbon rims and rain and rim brakes = bad. Carbon rims and rain and disc brakes = good.

MattC59

It's gonna happen.
My mate was talkig to a Shimano development engineer a couple of weeks ago, and Shimano are way into the development cycle for hydraulic disc brakes for road bikes.

Monty Dog

Inevitable and further to my comment on the BR article - their impact in CX is marginal, or is someone going to tell us that Sven Nys wouldn't have crashed today if he was riding discs?
However, whilst the UCI insist on keeping weight limits, then there will be no effective weight penalty and actually making braking in the wet with carbon rims a far better prospect. However, one downside could be an increase in crashes during higher-speed descents - human psychology is that riders will compensate for 'better' brakes by increasing speeds.

markos1963

I can see the pro's and con's of discs and I reckon they will come in for most road bikes some day. Most commuters,CX's and winter road bikes would gain a benefit from discs but I doubt that RR bikes would switch quickly as changing a wheel in a race would take longer/ be more difficult. Personally I can't see a benefit in the dry, with a well set up caliper and pads matched to the rim my braking ability is governed by tyre grip rather than brake force.

McBain_v1

Like Marcos1963 says, I could really do with a pair fitted to my winter hack - not really arsed about a weight penalty on that bike, more interested in stopping power in rubbish weather conditions. On my best bike I am going to stick with my Dura-Ace brakes which have done plenty well up until now

Gizmodo

As the title of this poll says, Disk brakes are going to happen. The question is whether they have any advantage for the inexperienced rider, to which I think the answer is no. I can happily lock up rim brakes in dry conditions and having extra braking power In the wet seems useful, the tires won't grip the wet road surface so will just result in skidding.

Do I want disk brakes, yes, but then I also want electronic shifting. Will it make me quicker/safer/more efficient, no I don't think so. There might be 1 time that they shave a few feet off my braking distance, but I don't think they will make a significant impact on the inexperienced, ameteur cyclist like me. But then I'm not an expert.

Smokin Joe

Gizmodo wrote:

I can happily lock up rim brakes in dry conditions and having extra braking power In the wet seems useful, the tires won't grip the wet road surface so will just result in skidding.

You've put your finger on the problem with caliper rim brakes. They are an inherently weak system needing a lot of force to apply in an emergency which makes it difficult to regulate braking force and makes loss of traction more likely. A more powerful brake can be applied with a sensitive touch, as is the case with motorcycles where a couple of fingers are all that are needed on the front brake to off scrub speed very quickly.

You very rarely hear a car skid these days and they are all fited with front discs, yet in the time of drum brakes the screech of tortured tyres was quite common sound because at anything more than a gentle stop you had to bury your foot to the floor and all sense of feel was lost.

fast as fupp

cars dont skid these days as most are fitted with anti-lock braking systems

Smokin Joe

fast as fupp wrote:

cars dont skid these days as most are fitted with anti-lock braking systems

I've never had a car with anti lock brakes, but I've had plenty of cars and bikes with drum brakes and I know which system is easier to bring a vehicle to a controlled stop.

Mike67

fast as fupp wrote:

cars dont skid these days as most are fitted with anti-lock braking systems

Now there's a thought...bikes with antilock disc brakes :shock:

meanredspider

Smokin Joe wrote:

Gizmodo wrote:

I can happily lock up rim brakes in dry conditions and having extra braking power In the wet seems useful, the tires won't grip the wet road surface so will just result in skidding.

You've put your finger on the problem with caliper rim brakes. They are an inherently weak system needing a lot of force to apply in an emergency which makes it difficult to regulate braking force and makes loss of traction more likely. A more powerful brake can be applied with a sensitive touch, as is the case with motorcycles where a couple of fingers are all that are needed on the front brake to off scrub speed very quickly.

You very rarely hear a car skid these days and they are all fited with front discs, yet in the time of drum brakes the screech of tortured tyres was quite common sound because at anything more than a gentle stop you had to bury your foot to the floor and all sense of feel was lost.

Spot on.

Mike67

Smokin Joe wrote:

Gizmodo wrote:

I can happily lock up rim brakes in dry conditions and having extra braking power In the wet seems useful, the tires won't grip the wet road surface so will just result in skidding.

You've put your finger on the problem with caliper rim brakes. They are an inherently weak system needing a lot of force to apply in an emergency which makes it difficult to regulate braking force and makes loss of traction more likely. A more powerful brake can be applied with a sensitive touch, as is the case with motorcycles where a couple of fingers are all that are needed on the front brake to off scrub speed very quickly..

Surely that's the issue with any braking system. In an emergency you're hardly likely to apply a sensitive touch...more like panic full on grab both levers with all your might :shock:

So with more powerful disc brakes (and skinny slick tyres) the lock up will occur sooner and at higher speed...skid city!

I've never had a problem with modulation on my calipers and once set they hardly need to be fiddled with at all. More than enough to stop me from 40mph plus down some pretty steep hills and I can still lock them up if I want/need to. I guess effectiveness may vary dependant on pads and from brand to brand and bike to bike etc.

The disc brakes on my MTB on the other hand are a PITA...squeaky, scratchy, rub rub squeal squeal and you need to mess around with nasty brake fluid and hope you don't drip any on your paintwork
Must admit they are good in mud though and you don't wear a pair of (rim) pads out in one ride.
I do try and avoid mud on my road bike though

cougie

Smokin Joe wrote:

fast as fupp wrote:

cars dont skid these days as most are fitted with anti-lock braking systems

I've never had a car with anti lock brakes, but I've had plenty of cars and bikes with drum brakes and I know which system is easier to bring a vehicle to a controlled stop.

If you've not had the ABS before - then how would you know ?

FWIW I dont think we'll get disk brakes to be common on road bikes until they're used in pro races.

Smokin Joe

cougie wrote:

Smokin Joe wrote:

fast as fupp wrote:

cars dont skid these days as most are fitted with anti-lock braking systems

I've never had a car with anti lock brakes, but I've had plenty of cars and bikes with drum brakes and I know which system is easier to bring a vehicle to a controlled stop.

If you've not had the ABS before - then how would you know ?

FWIW I dont think we'll get disk brakes to be common on road bikes until they're used in pro races.

I was referring to discs v drums, not anti lock.

MichaelW

SRAM is working on a hydraulic road brake lever and apparently, so, apparently, is Shimano but I think they misunderstand the need for disks. Normally, new tech (like electronic shifting) is introduced at the very top level and trickles down. We all know that the real beneficiaries are going to be commuters, CX riders, tourists, tandemistas and winter trainers in wet conditions. What the market needs is a Tiagra/105 level hydraulic road disk brake, so commuters can afford it and CX riders can experiment. A Dura-Ace hydro brake will be a failure in the pro peleton because it offers little advantage so the technology will not be developed further.

SRAM and Shimano are global companies and they dont make groupsets for riding in the cold and wet because over in Ad-land, all riding takes place in eternally dry, sunny California. I think we will be very fortunate to ever see an affordable road hydro lever.

Tom Butcher

But it does offer some advantage - the ability to ride all carbon wheels and still be able to brake effectively in all weathers - at effectively no cost too because the bikes will still hit the minimum weight limit. Even plenty of pros will not ride carbon rims on wet Alpine descents and at the other end of the spectrum some amateurs have been known to blow tyres off the rim after dragging their brakes all the way - IF disc brakes work as well as people say then these should be things of the past. People are willing to pay a lot of money for a slightly lighter frame or groupset - if this offers some genuine advantage - no matter how small - then there will be a market for it and the manufacturers will be keen to cash in.

The pros ride what they are given so unless discs are actually a disadvantage I can't see them having a problem with them.

meanredspider

I'm using disc brakes on my CX bike that I use for winter commuting. I'm absolutely sold on disc brakes for wet weather use - they are so so much better than rim brakes even with "wet weather" pads.

Being able to lock the wheel isn't a good measure of the effectiveness of a braking system. As mentioned above, it's all about modulation. In fact, a locked wheel is a useless wheel. Discs give me far more confidence to push harder on downhill sections as I can modulate the much higher forces much easier and get closer to the limits of adhesion much more predictably. I'm using exactly the same tyres as I'd use on my carbon road bike in the wet. The biggest difference is when I swap back to the road bike - the brakes feel really horrible.

I think I can reasonably confidently predict that in 10 years, discs will be the norm on road bikes. The bike industry is slow to respond (even finding CXers with discs isn't as common as you'd expect). I agree too that the top end isn't the place to start - light bikes with light pro riders ridden on stages with less braking than us mortals do, isn't the place to prove out better braking systems. The real world with heavy riders, heavy bikes, traffic, weather, red lights etc is where they really count.

t.m.h.n.e.t

IMO t's one of those things that if the tour pros adopt,then slowly the tech will filter down through consumers.

This isn't a bad thing,pros are probably the best people to help fault find and develop.

nwallace

Hydraulics seem excessive on the road to me, the cable actuated BB7s are fine, just not quite as fit and forget as hydraulics are.

Tom Butcher

The other thing about the argument that we don't need more braking power - you can lock the wheels with the cheapest 1980s single pivots - but I bet most of us would prefer Record or Dura Ace with Swiss Stop pads. So there has to be more to braking than just having enough power to stop the bike. I just think until we've actually tried discs on a road bike it's impossible to know for sure if they offer "better" braking - most of those that have tried it on similar type bikes do seem to prefer it.

roger_merriman

Tom Butcher wrote:

The other thing about the argument that we don't need more braking power - you can lock the wheels with the cheapest 1980s single pivots - but I bet most of us would prefer Record or Dura Ace with Swiss Stop pads. So there has to be more to braking than just having enough power to stop the bike. I just think until we've actually tried discs on a road bike it's impossible to know for sure if they offer "better" braking - most of those that have tried it on similar type bikes do seem to prefer it.

the arguments against are ideological, on the whole.

this said I would guess that Dual Pivots due to there ease of setup and maintenance, would remain much more so than V brakes have.

MattC59

Don't you just love all of the 'they don't offer any advantages', 'they're a waste of time', 'why would the pros use them' comments.
How about:
Consistant all weather braking.
Consistant braking despite rim material.
Better brake modulation.
Lighter weight rims (therefore lower rotational mass) as the rims don't need to handle the wear.
No over heating issues on long descents.
Ease of maintenance.

Anyone want to add any more ?

The weight argument isn't really an issue either as most Pro bikes come in under the UCI weight limits, so there ballast wouldn't be needed to bring the bikes up to the minimum weight limit.

The whole point of disc brakes for the road isn't to get more powerful braking, after all the amount 'power' that the brakes have is limited by the grip of the tyre, it's to get better, more controlled braking.

Smokin Joe

MattC59 wrote:

Don't you just love all of the 'they don't offer any advantages', 'they're a waste of time', 'why would the pros use them' comments.

I've been at this a long time.

All the same arguments were used against clipless pedals, indexed gears, computers, each new sprocket addition, integrated shifters, aluminium, carbon fibre, sealed bottom brackets, A-headsets, electronic shifting and no doubt pneumatic tyres back in the nineteenth century.

Cycling does attract it's share of luddites.