Disc brakes?

georgee

Personally very pro,

All thoughs saying not much better than DP's get in the real world and go and ride a decent disc equipped bike, especially in the wet, I was genuinely shocked when I took my first road bike out in the wet, pretty scared of how this performance was justified as acceptable!

http://www.bikeradar.com/gear/category/ ... c-08-28049

Am I the only one to have seen this. not a stunning review, but proves people are looking, someone needs a good chat with the boys at ribble, put a carbon disc fork and mounts on their winter bike and it would be a dead cert for my winter hack of choice.

markos1963

I can see why the MTB boys like discs so much, they do offer better feel and the power is almost limitless if hydrolics are used. However they do have the advantage of suspension forks which can absorb the forward weight transfer and give the confidence needed to brake hard which road forks dont. I would use discs on my bikes if it were for wet weather use and improved rim life but as for power its a non starter as I wouldn't want to use a suspension fork to be able to use their power.

drenkrom

If you can lock up your wheel in the most drastic braking scenario (which I most definitely can), there can be no improvement. That's it. You ain't getting better than that. So no added performance.

Plenty of added weight, though, and rotating weight at that. And plenty of hydraulics nightmares, as anyone who maintains a DH bike will know (my road bike never ruptured a cable and ruined my shorts with hydraulics oil). Plenty of added unidirectional stress to road spokes and rims that were never meant to take it in the first place, resulting in plenty of off-true wheels.

You'd imagine they'd be better for many of the reasons stated by other people, but common sense rarely stands up to scrutiny. If they were better than dual-pivots, the pros would be riding them. They really are an "Uncle Joe goes cruising" thing.

No offense....

Sea_Green_Incorruptible

My next road bike will have Disc brakes - end of story (Orbea Diem drop disc looks good or maybe go with a disc'ed up crossser or Trek Portland).

95% of my riding is commuting, and while my Ultegra cantis will stop me dead in the dry they don't modulate like discs; and they simply fail in the wet. Not in the market for a new bike for a while though, so might go with converting to the front disk option if I can get round to it...

I couldn't believe how good discs were when I first got an MTB with them. It really is the most noticable upgrade/improvement I've ever noticed on a bike, except perhaps for STIs...

giant_man

redddraggon wrote:

giant mancp wrote:

I don't see the need on a bicycle personally.

I can understand the need for them on MTBs maybe, but not road bikes.

I wouldn't know, I don't ride bikes that look as though they were made for children

meanwhile

drenkrom wrote:

If you can lock up your wheel in the most drastic braking scenario (which I most definitely can), there can be no improvement. That's it. You ain't getting better than that. So no added performance.
[/quoting]

What about performance in the wet? Rim brakes have a delayed onset at the least, and surely it's the first moments of emergency braking that can be most valuable?

Plenty of added weight, though, and rotating weight at that.

The effect of rotating weight depends on the radius of rotation. Something as close to the axle as a braking disc doesn't add much to the energy required to get a wheel up to speed (which is a radius squared thing). Plus the whole phobia about rotating weight is mostly voodoo.

And plenty of hydraulics nightmares, as anyone who maintains a DH bike will know

Avid BB7's are w-a-y powerful and use cables.

If they were better than dual-pivots, the pros would be riding them. They really are an "Uncle Joe goes cruising" thing.

No offense....

None taken! Some people don't understand that the Tour De France and Real Life are different things. E.g. the Tour doesn't ride through traffic in the rain, and racers have used drugs that risk their lives to get a few minutes off their time for the day's racing - something most of us aren't willing to do to speed up our commute by a couple of minutes. Dual pivots make sense in the Tour because nothing is better ***in the context of the Tour*** - at least as disc weights stand. Most of your prejudices against disks are "Uncle Joe watches the Tour and imagines that turns him into an expert" things. No offense...

Otoh, the UCI have banned discs from Cyclocross, where braking power does count, as an unfair advantage.

Good article on discs and road bikes here:

http://www.velonews.com/article/75604/t ... big-things

- the author, US bike builder Leonard Zinn, thinks discs will be a great thing for road bikes when they are a little lighter. He quotes a case of rider being killed - yes, on the Tour! - who would be alive if he had discs.

markos1963

I still can't get the arguement for discs on power grounds. If I can lock up my 105 calipers at will, then why would I want anything more powerful, what i need is more grip from the tyres before anything else. In the wet I dont want power I want feel, so dics make sense there.

meanwhile

markos1963 wrote:

In the wet I dont want power I want feel, so dics make sense there.

Is that what's called a Freudian skid..?

simbil1

Markos,
I agree about the 'power' - not sure what some people mean by discs being more 'powerful'?
Where discs are great is being able to get very close to locking the wheel without actually making it stop turning completely - this is modulation and where discs are miles ahead of dual pivot brakes.
Not that well set-up dual pivots with good pads aren't bad - they are adequate but require a higher level of skill to get the most out of them as the modulation is more on/off especially when braking hard.
I'd like to see a downhill test with the same rider descending on dual pivots and then discs, I'd be really surprised if the discs didn't get the vote every time when they are actually compared in real life rather than just speculated about in theory.

Smokin Joe

markos1963 wrote:

I still can't get the arguement for discs on power grounds. If I can lock up my 105 calipers at will, then why would I want anything more powerful, what i need is more grip from the tyres before anything else. In the wet I dont want power I want feel, so dics make sense there.

I could lock the wheels on my Morris Marina with drum brakes all round, but I sure as hell wouldn't want to go back to them. Brakes that apply their power with a light touch give much better feedback to the operator.

meagain

"All thoughs saying not much better than DP's get in the real world and go and ride a decent disc equipped bike, especially in the wet, I was genuinely shocked when I took my first road bike out in the wet, pretty scared of how this performance was justified as acceptable! "

Sums it up nicely IMO/E. And quite apart from the superior performance, discs also negate the scrubbing the rims after every wet (this year seemingly every!) ride. I sure ain't doing another winter without disc (or even hub) brakes - and hub gears as it happens.

Jon8a

Can't be bothered to read this lot now but I voted no. The limiting factor IME is the grip of the tyres on the road. Using SORA brakes I can lock up my rear and my front if I keep my weight back. Discs would just make this happen sooner. Would be nice to have light one finger braking like I do on my mtb.

andrewgturnbull

Hi there.

I try not to use my brakes anyway... they just slow me down!

Cheers, Andy

ddraver

Weight is not a factor stopping pros using disks - most of them are using alloy bars because they have to get their superlight frames up to the UCI minimum weight...

i still maintain that it will never happen untill someone designs a road race bike specific brake in tandem with a major frame manufacturer making a disk only frame (no point in puttin DP mounts on - pimps won't like the left over look and the strengthening can be put to beter use elsewhere on the frame/fork. Also road race disk rims will be needed allowing the remoal of e the uneccessary braking surface so the rims can be better made to combat the effects of disk brake use and such

Note i say road race specific - not like BB7's that are cross compatable but a road specific lever/hose/caliper design - as in you buy a "Dura ace Disk brake" the same way you buy an "XT disk brake"

the disks will not need to be MTB powerful either in disk size or caliper strength as the tyres will not have the grip required to utilise it so already we can knock some weight off with smaller disks

I'd love the increased modulation, ease of use ( eg one finger braking) and wet weather reliability that they would bring to road bikes - the ony issue i can see is the massive squealing noise coming from the peleton while 150 odd disk brakes make their characteristic rainy day noise
Looking at the MTB market I'd say Spesh will be the first ones to do it - transfering the ethos they used on the FSR and enduro bikes where everything was made specifically for one bike and not to be cross compatiable with other bikes - the cross compataility issue is slowing down bike development IMO - possibly more so than the UCI - especially w.r.t MTB's (but thats another story)

Tom Butcher

meanwhile wrote:

- the author, US bike builder Leonard Zinn, thinks discs will be a great thing for road bikes when they are a little lighter. He quotes a case of rider being killed - yes, on the Tour! - who would be alive if he had discs.

Is that the Beloki crash he mentions ? Beloki didn't die - it was a bad crash and he was out of racing for a long time but he did make a comeback at the top level - though never achieved the same form as he had before the crash. He's making a bit of an assumption about the crash too isn't he - I thought it was the melting road surface that was responsible for the wheel locking up more than the brake grabbing - could be wrong of course.

georgee

A major problem here is the lack of innovation which normally comes from pro sport. The most obvious application for discs are on cross bikes, but the UCI banning their use merely stifles this. Think of what developments have come out of F1 in the last 20 years, one years development is equal to 5 in the normal world, why else are they looking at allowing alternative power sources next year such as hybrid engines.

The only drawback I can see to develop wheels with equivalent lateral rigidity as I am sure the route to including disc mounts will be to narrow the with between the two flanges.

jedster

Last night I rode down a 1 in 10 with hairpins in the driving rain (it was VERY wet). The cantis on my planet-x uncle john were really struggling with me hauling on them from the drops. For the whole commute, I could get very little braking from the hoods.

I'm going to look at getting a front disk brake.

Anyone know of a dyno hub that is compatible with disc brakes?

J

Jez mon

I can just picture the UCI at the start line of a race in a few years time. A team comes out in with disc equiped bikes, testing them for the latest, Campag/SRAM/Shimano gruppo. Some suit comes out takes one look and tells them to put proper brakes on their bikes.

The UCI don't have a rule about it now, but that doesn't mean they won't write one as soon as anyone dares to use them in a road race.

Personally, if a light small aero (perhaps dimpled ) disc can be introduced, i can see tremendous advantages, safer stopping in the wet on carbon wheels for one.

However, it's possible to lock up a front wheel currently disc brakes aren't going to help this, and incase you haven't locked up your front wheel, its a very scary experience.

JC.152

Not many people (race organisers, pro riders) listen to the UCI any more, so in a few years time you never know rules like this might not matter.

Jez mon

Just a thought, will the bikes in this years Tour be subject to the UCI's rules and regs?

Smokin Joe

Several posters have repeated the myth that the more powerful a brake is, the easier it is to lock the wheel. That is not the case, powerful brakes tend to have much better feedback and the softer pressure needed to apply them allows you to regulate the braking force much better.

It is crap brakes that lock up when you have to strain every sinue to get them to bite, to the point where you loose all sensitivity and suddenly find you are overdoing it.

Neil Fat man on a bike

I must admit .... I love disc brakes.
I've had all manor of rim brakes and a variety of cable and hydraulic disc brakes.
The disc brakes win every time in terms of ease of use ( modulation/feel ). They work immensly better in the wet ! It is most deffinatly the way forward.
I only wish there was an affordable way to equip my Mercian tourer with discs as it is being sent off for retoration this week.
Any affordable disc options out there ?

meanwhile

jedster wrote:

Last night I rode down a 1 in 10 with hairpins in the driving rain (it was VERY wet). The cantis on my planet-x uncle john were really struggling with me hauling on them from the drops. For the whole commute, I could get very little braking from the hoods.

I'm going to look at getting a front disk brake.

Anyone know of a dyno hub that is compatible with disc brakes?

J

Good news -

http://www.bikefix.co.uk/index.php?get_ ... sgl_id=126

But, really, if you put disc fork on the front of your bike you should get a lot of the benefits of disc brakes on the road. Rear wheel braking is only important in slippery conditions, like mud or riding over lose shale. Even in the rain the front brake should be carrying the load.

meanwhile

Smokin Joe wrote:

Several posters have repeated the myth that the more powerful a brake is, the easier it is to lock the wheel. That is not the case, powerful brakes tend to have much better feedback and the softer pressure needed to apply them allows you to regulate the braking force much better.

It is crap brakes that lock up when you have to strain every sinue to get them to bite, to the point where you loose all sensitivity and suddenly find you are overdoing it.

One of the things I've picked up from thread is that discs often have better modulation. I think I'll definitely be riding a disc fork on the road this winter.

meagain

This has prompted me to seek a disc braked 700c bike! Not a lot, is there? Kona Sutra, Lemond Pob???, Focus Crosser most obvious. Unfortunately all have horizontal top tubes. Even came across a Raleigh Pioneer Elite - discs AND hub gears - but even the Raleigh site says sold out!

Am I missing any obvious contenders at less than a grand?

lateralus

why not just get a disc fork? as said above, front brake does most of the work - in my motorcycling days there was a school of thought that if the back wheel is still on the ground, you're not braking hard enough with the front (I know, I know, suspension and all that, but still partly true), so disc specific frame not really needed.

edited to add - if you want cheaper and are happy with ss/fixed, I think Cotic do a built up Roadrat frame for £600-odd. the top tube on that slopes big time!

meagain

I am indeed tempted by the Roadrat - but I'm getting soft and gears also tempting! Though I think the Cotic CAN be built geared?

ddraver

yes it can......its an MTB style frame made in road tubes though

but oh what a frame :P

Ken Night

meagain wrote:

I am indeed tempted by the Roadrat - but I'm getting soft and gears also tempting! Though I think the Cotic CAN be built geared?

Dave. Try Salsa's Las Cruces, Karate Monkey, etc, van Nicholas' Amazon (you've had the Airborne CD haven't you?) Kaffenback or Uncle John? Kona Sutra

some of these come with disc tabbed carbon forks.

As I've said above-Kinesis are about to launch some forks-and if they do that, I guess they'll launch a disc ready frame too?

Let us know how you get on, by reporting back here

meagain

Ken Night wrote:

meagain wrote:

I am indeed tempted by the Roadrat - but I'm getting soft and gears also tempting! Though I think the Cotic CAN be built geared?

Dave. Try Salsa's Las Cruces, Karate Monkey, etc, van Nicholas' Amazon (you've had the Airborne CD haven't you?) Kaffenback or Uncle John? Kona Sutra

some of these come with disc tabbed carbon forks.

As I've said above-Kinesis are about to launch some forks-and if they do that, I guess they'll launch a disc ready frame too?

Let us know how you get on, by reporting back here

Good memory! Though actually the Airborne I had was a Valkyrie! And I've had a Kaffenback! Thanks for all the other suggestions - and, yes, 'guv, I'll report back! But it may be a little while....