POLL: Disk brakes on road bikes?

confused@BR

And when they do become the standard, be ready for really tasty offers on rim braked bikes which will tempt you

thecrofter

Everyone's talking about the extra weight of disc.....but they'll just trim the weight from elsewhere. Currently, as I understand it, the only limiting factor on how light bikes are is the UCI regulations. If manufacturers were given their head they could produce bikes markedly lighter that those the pro's currently use. i'm sure I've heard of the pro teams adding lead weights to bring bikes up to spec. UCI = anti technology, it could be argued.

My 2p-worth

APIII

Monty Dog wrote:

The big advantages of disc brakes are:
Lighter rims e.g. carbon and no need for heavier, sacrificial brake tracks and no worries about overheating rims / tyres.
As well as absolute brake power, modulation and control is better too - you can often brake mid-turn without it upsetting the bike handling.
They work, regardless of weather unlike rim brakes e.g. carbon rims in the wet are rubbish

Yeah, so not much benefit to most.
Most people don't want carbon rims, nothing to do with braking, more to do with cost and durability. You would struggle to overheat rims from braking in the UK. If you need to brake mid turn, you should improve your handling skills.

Ber Nard

The argument that rims can be made lighter and more aerodynamic if there's no need for a brake track is a good one, but wouldn't these rims have already been born out of track cycling? There's never been a need for brakes of any description on the track. I know they use disc and full composite wheels but that's only at the top end.

I say this quite ignorant of track cycling (I watch it on the telly and it ends there) so I'm happy to be proved wrong.

Rob

NWLondoner

Remember rims for track cycling are designed just for that TRACK!!!

I wouldn't fancy riding on track rims on the open roads.

I know people knock carbon rims but as one who uses them they really do ride so well. Remove the braking issues and many more people may make the switch

Ber Nard

NWLondoner wrote:

Remember rims for track cycling are designed just for that TRACK!!!

I wouldn't fancy riding on track rims on the open roads.

Why not? What are the differences? The rims don't seem to be much different to normal road rims.

Rob

buckmulligan

Call me old fashioned, but I think disk brakes ruin the aesthetic of a road bike, but I think they'll become the standard sooner-or-later what with the relentless march of progress and all that. Personally I'd like to see the fork-integrated-brake-callipers as per the BMC time trial bikes (and probably many other pro teams) become more mainstream, but I very much doubt we'll see those any time soon!

proto

Coming down the Tourmalet and Aspin in the rain this year, easy decision for me, DISCS!!

That's apart from the option of carbon rimmed wheels entering the mainstream, and much lighter wheels for everyone.

cougie

Alain Quay wrote:

One clear advantage of disc brakes is this:

If you are on a continental sportive, stop on a steep mountain descent and listen. You will hear tyre tubes going 'bang' every few minutes. If I am correct, discs should eliminate that potentially dangerous risk from (usually) front tyre blowouts from anxious amateurs or those with over-inflated tyres overcooking the brakes.

That aside, it looks like the industry will push this as de rigeur, to keep the bike business ticking over.

Let the numpties buy disk brakes if they want to then ?
They'll just fund more interesting ways to crash.

Babel Coglioni

Idealism (bollocks)

Rim brakes are slow suicide. Abrading the thin hoops that keep you gliding above a surface that would otherwise rip your skin open is folly. It is only a matter of time before they catastrophically onion-ring beneath you. Wear indicators? They’re a symptom of the problem!

Pragmatism

The thought of a piston transferring heat to hydraulic braking fluid so that it boils, causing total brake failure, currently makes me favor cable-actuated disc brakes over hydraulics. But perhaps better technology will solve that problem.

I'm waiting for road disc brake technology to evolve some more before I buy in. I have in mind a single-speed road bike with a carbon belt drive and disc brakes. In the meantime, I'll try to keep my rims and brake pads clean, and heed the wear indicators.

springtide9

Babel Coglioni wrote:

The thought of a piston transferring heat to hydraulic braking fluid so that it boils, causing total brake failure, currently makes me favor cable-actuated disc brakes over hydraulics. But perhaps better technology will solve that problem.

Good point. We should all go back to drum brakes on our cars and HGVs. Imagine putting disc brakes on cars that can weigh in excess of 2 tonne and can travel in excess of 100mph :roll: Or maybe switch to cable disc brakes for cars?
Boiling hydraulic fluid must be a daily occurrence and I guess 100's of lives are lost every day due to hydraulic disc brakes on our roads.


What was that phrase, oh yes, "Designed for purpose"

reformedfatty

Discs for me. All weather braking capability, more powerful brakes, rims no longer a consumable. What's not to like?

I can see it might not be the preferred option in professional competition with the current systems, but it will get there in time.

Mikey41

IMHO I'm amazed it's taken this long for disc brakes to appear on road bikes! The cable discs on my hybrid are far better than the brakes on the roadie, so I'm tempted to wait for discs to become the norm before looking at a better bike.

mattshrops

Well you've made some marketing men very happy. Another triumph for engineering a solution to a problem that doesnt exist.

Initialised

Discs on road bikes?

Why hasn't it happened yet?

I think we're at a tipping point around now











I guess eventually manufacturers will get sick of selling what really are just road bikes with discs as 'Cross', 'Hybrid' or 'Winter Trainer' and force conservative organisations to relax the rules as they did in cross recently.

For now the choices are limited go for one of the above, buy a decent hybrid and add drops (and the rest) or buy a CX.

Babel Coglioni

springtide9 wrote:

Good point. We should all go back to drum brakes on our cars and HGVs. Imagine putting disc brakes on cars that can weigh in excess of 2 tonne and can travel in excess of 100mph :roll:

You're right, it never happens.

Given the relatively miniscule scale and low weight of components on a road bike, heat dissipation from disc brakes is a significant issue.

symo

A properly set up disc has no drag.
Unfortunately on a wheel change you now have a different disc - will there be no drag?
Next question; what about the weight of the hydraulics, the disc and the fluid you are now carrying around?

giant_man

its gonna happen whether we like it or not, so we might as well embrace it ... but I haven't tried a bike with discs, so I don't know what they feel like, stopping safely in the wet is one reason why I would buy a bike with discs.

beverick

Babel Coglioni wrote:

springtide9 wrote:

.............

You're right, it never happens.
.....

"In hindsight, it was poor parts selection for the actual use."

Bob

Babel Coglioni

beverick wrote:

"In hindsight, it was poor parts selection for the actual use."

Yes, I saw that. The specific details of the accident are interesting, but even more interesting (to me) are the comments from the manufacturers. For example:

When you whittle everything down to a super lightweight package, the only place for all that heat to go is the hydraulic fluid, and you can boil it in no time at all.

Depending on your point of view, using hydraulic disc brakes on road bikes either introduces new problems that are not experienced in larger-scale applications, or alters the "parameters" (severity) of existing problems (roll your eyeballs if you like, but heat dissipation is also an issue in other applications), or both.

I am looking forward to this technology evolving, but as others have already pointed out, I think that the success of disc brakes on road bikes depends not just on disc brake technology, but also on frame and wheel manufacturers investing in disc-specific designs. For example, rims that are lighter (because they do not have to withstand being squeezed), have no braking surface, and where both front and rear rims are designed for asymmetrical dishing.

Tom Butcher

Clearly the guy in that link wasn't using very good technique - dragging the brakes all the way down to keep speed down - the problem I suppose is that is exactly how a fair number of people will tackle difficult descents, I probably did it myself when I started out. It's a bit worrying that the Shimano rep quoted actually says ....

"I think technique will help too, riders may need to brake hard for a short distance, for instance coming into and going around the corners, then let off so they can cool. I think in your situation, you were on the brakes the whole time and they simply got too hot. "....

You can't really sell brakes that rely on people having the balls to stay off them between corners.

reformedfatty

Tom Butcher wrote:

You can't really sell brakes that rely on people having the balls to stay off them between corners.

If you prefer your skin to be on your body, not the road then you can't brake hard whilst cornering with current systems.

Tom Butcher

Obviously I mean brake coming into the corners rather than drag your brakes all the way down the descent.

snoopsmydogg

symo wrote:

Next question; what about the weight of the hydraulics, the disc and the fluid you are now carrying around?

use a cable operated disc? better feel and performance than calipers but not carrying the weight/potential fluid boiling issue of hydraulics.

or just lose the extra weight elsewhere on the bike

symo

But still more weight, no? Despite what others say on this thread there is still the issue of brake rub, and also the rim will surely experience more force from a disc, so the weight saving goes there?

Personally I know it will happen, just makes our nice simple bikes look a bit cr@p IMO. BUt I still see swapping wheels as an issue. On the other hand i did fancy an On-One Pompetimine with 8 speed hub gears and the cable discs for commuting on.

Babel Coglioni

Initialised wrote:

I think we're at a tipping point

I agree. This is one reason why I'm holding off investing in my "dream" single-speed road commuter: I really like my current commuter (a 2007 Specialized Langster), and there is no real need for me to upgrade, but I covet a titanium-framed equivalent with higher-spec (and, hopefully, even lower-maintenance) components. I like the idea of disc brakes, but I do not want to be an early adopter, for various reasons. And I don't want to spend big bucks now on a Ti frame with rim brakes in case, in only a few years' time, I'll be looking around me at all the hydraulic disc-equipped road bikes and wishing I'd waited. I understand that (especially now, in 2012) a single-speed road bike with disc brakes is a relatively niche item (low demand), but I wonder how many other people are holding off buying their next road bike until disc brakes become commonplace?

It's possible, and understandable, that future road hydraulic disc brake levers might only be available with integrated gear shifters - as I gather will be the case for SRAM Red 2013 - but I hope there will be options for single-speed bikes, too.

Mikey41

Why do they even need to be hydraulic? Seems to add complication for little gain, a cable operated system would do just fine.

The guy in the article dragged the brakes all the time, heated them right up and boiled the brake fluid by the sounds of it, just as you might do in a car on a long steep descent.

ddraver

Yes, but not until someone has the balls to start making proper disc specific frames for proper, designed only for road specific brakes...

The current bodge jobs (Colnago/Formula aside, but then that needs more development R&D at present) won't sort anything!

symo

On One pompetimine 8 speed and cable discs.

Already made.

ddraver

Fine but that's not a race bike is it (which I think is what the question is more about). And to be honest, Volagi, on-one or colnago are nt big enough. If it's going to happen it will need to be a Trek/Giant/Spesh type company with a frame (and wheels for that matter) designed purely for disk use.

But most importantly, they need to be used in the Pro Peloton as the majority of us are suckers who want to ride what our fave rider rides!