Road Bikes - Why no hydraulics?

[Bicycle]

I was a slow and very reluctant (Luddite) convert to hydraulic discs on MTBs.

I have now seen the light, but I wouldn't want them on anything I used on the road.

Discs are very powerful, stay out of the much and water, don't wear the rims out and offer extraordinarily constant braking through hard use.

None of those qualities is absent on any road bike I ride to the extent that I'd consider upgrading.

I imagine that the things people were doing on MTBs outstripped the abilities of rim brakes.

On road bikes, we seem not to have reached that point yet.

 

[YahudaMoon]

Aint those hydraulic systems massive ?

Id love a disc brake hydraulic MTB. How much a decent one cost ?

 

[steve52]

bring on discs i could then buy carbon wheels, haveing worn 2 sets of rims out pah !!!!!

 

[Wobblers]

Could the reason for there not being any road bikes with hydraulic brakes simply be that they don't need them and that the systems that are already used present the the most efficient way of stopping and slowing?

Harrumph. I really must introduce you to the "braking" of my Galaxy in the wet.

The fact is, a well set up rim brake is every bit as good as disk brakes - in the dry. Hydraulic disk brakes do give you better modulation though. Which is nice, but not really essential. Where disk brakes shine is in the wet. Even the best rim brakes need one revolution of the wheel in order to remove the water off the rim before biting. That's two metres of travel which could make a big difference in an emergency. Disk brakes work instantly. I know which I'd rather have when it's raining.

As for the front forks not being up to coping with the additional torsional loads imposed by disk brakes? I'm skeptical. Forks have to cope with very high loads on occasion (particularly when you're crashing through that pothole you couldn't avoid!). If they can't cope with disk brakes, they're not fit for purpose.

 

[Evil Rabbit]

There are, as I only found out recently, hydraulic rim brakes for road machines.

 

[gaz]

Hydraulic rim brakes

 

[aoj]

It is coming to cyclocross due to a rule change, so expect a slick solution eventually.

In the mean time here is one inventive solution

http://www.cxmagazin...locross-cannard


How do the road bike racing rules stand on disc brakes?

It would need for them to be common place in the TDF or the like due to being an advantage (unlikely at present ) before they would be universally adopted on road bikes.

 

[Black Sheep]

I was just wondering...

On road bikes, why are there no hydraulics disk brakes?

Also, has there ever been any hydraulic derailleurs (front & rear mech's) developed; if so, why aren't they used? If not, why not? Wouldn't this completely remove missed gears/wrongly indexed gears?

Surely they don't weigh that much heavier?

Discuss...

forks are too skinny / light on racing bikes to fit a disk brake due to the forces involved, you also can't use aero spokes or radial spokes as the braking force is transfered from disk, to hub, through the spokes, to the rim.

some touring bikes can be fitted with them


I've not come across hydraulic derailleurs, but Shimano did do a preasurised air version which was prone to changing gear on its own due to air pressure varying with temperature, it also wasn't great at not failing at the seals etc

the weight of a hydraulic set up is more than a cable set up and would be more complicated to adjust

if it works, why change it?

 

[StuAff]

There are road bikes with discs, mechanical ones at least. Volagi (a recent American start-up) are producing full-carbon road bikes specifically designed to use discs. There are many advantages to having discs rather than rim brakes (zero rim damage & more tyre clearance to name but two), though I'll agree there are drawbacks too. Judging by the specs, weight penalty if any is negligible.

 

[Piemaster]

I don't see the problem really being down to the frame/forks/wheels/whatever. I've just swapped the all carbon fork on my pomino for a pompetamine fork, partly to get the disc mounting and partly for something to get mudguards onto (Ok, its now the same colour as the frame too, which is quite nice). I've been left with a canti at the rear which I'm not bothered about as most of braking is done on the front anyway and the frame does not have a rear disc mount.
Theres a few other road type frames available for discs now too.

Its the fact that there are no drop bar hydraulic levers available though I don't see why it isn't technically possible. Above link to a cable operated master cylinder just seems a bit messy. Something like the VRS drop lever for the alfine hub with cable pull for a rear disc on one side and a hydraulic setup for the front would leave me very happy.

 

[the_mikey]

I can't help but think that disc brakes on a road bike would prove to be a persistent nuisance, and so far, I've had no issues with calipers in wet or dry conditions.Unlike the mtb I had which had disc breaks and was a regular nuisance, especially one time when the wheel was knocked slightly out of true, it stopped all riding.

 

[Zoiders]

Cable operated master cyclinders have been kicking around for years - they were never that good or relaible so they never took off.

 

[betty swollocks]

I run a steel framed and forks fixed wheel road bike with a single Hope mono mini on the front. This brake is highly effective in all weathers and has been virtually maintenance-free in four years of constant use.
The only maintenance was a single change of brake pads.

 

[alecstilleyedye]

This topic has been moved to Know How by the admin team.

 

[rualexander]

Only reasons I can see for discs are (1) long descents with heavy loads, where rim heating stands a chance of blowing the tyre off the rim; (2) mud and dirt reducing braking efficiency. In dry conditions you can lock either or both wheels with ordinary rim calipers, so why pay the weight penalty?


For these reasons I think you'll see them on touring bikes long before race bikes

What about overheating of the discs causing them to warp, I think I read about that somewhere as a downside to discs on long descents with luggage.