Road Bikes - Why no hydraulics?

[cloggsy]

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...

 

[Simba]

A road bike with disk brakes would look and feel wrong on every level.

 

[lulubel]

My understanding is that disc brakes make a noticeable weight difference even on a mountain bike, where the increase is a much smaller percentage of the overall weight of the bike.

 

[HLaB]

I thought the weight difference was becoming negligible with new technologies but the quick maintenance on the road for racers is not possible and rules them out and most folk are a victim of fashion (including me ) and prefer a bike that looks like a pro's even if I can't ride like one

 

[gregsid]

It's also a case that MTBs are better suited to disc brakes as the brakes themselves are kept away from wet mud as much as possible. Road bikes don't normally have that wet mud issue and so opt for the simpler, lighter and hugely efficient rim brakes.

 

[MacB]

Weight difference exists but would be immaterial at pro level as they already add weight to keep above the limit at times....it would be far more noticeable to those weekend warriors that spend a firtune getting their bike weight as low as possible

Road bikes already exist with mechanical disc brakes and there have been hydraulic efforts in the past, what I've seen involved a cable connection from the lever to a master cylinder under the stem. Various rumours do the rounds of work in progress for a full road/hydraulic setup.

If you chose to use something other than a drop bar then you can have a road bike with hydraulics, this would work:-

http://jonesbikes.com/blog/?p=733

though the link to the TT results is no longer working so I don't know how he got on. If you look at the Jones H-Bar then you can replicate the ride positions of tops and hoods that you get on drop bars. Basically, like a moustache bar, it replaces the drop/hook position with a wider angled one. If you had something like this tilted towards you then there would be minimal difference to riding a drop bar bike. Unless you were a rider that spent a great deal of time in the drops.

Unfortunately they are eye wateringly expensive, but a similar result can be achieve with a set of On-One Mary bars and some inboard bar ends:-

http://www.flickr.com/photos/37729119@N08/5950667140/in/photostream

 

[Dan B]

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

 

[Piemaster]

With cyclocross now allowing disc brakes the possibility of hydraulic brakes for drops must be as close as its ever been.
Can't see they would be developed for tourers really as it can't be a very big market

 

[Ibbots]

I commuted for the last two years on a bike with hydraulic disc brakes - excellent in the wet but to be used with a light touch, especially the rear if you want to keep some rubber on the tyre. This was a converted MTB, though I have see some road frames with disc brake fittings by makers such as On-One and Kinesis.

 

[MacB]

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

Agreed for race bikes but the big appeal, for me, with general bikes is that you don't wear out rims and you can swap tyre sizes without worrying about claiper clearance(assuming frame allows of course).

But the OP mentioned road bikes and, to me, that doesn't just mean full on race machines.

 

[gaz]

From my understanding it's not possible due to how the brake leavers work.
Someone did develop a way to convert a cable pull to a hydrologic pull for roadbikes. That was several years ago.

Another issue is the flex in the forks. It won't be developed for pro's as they don't need them and they would have to build up the forks quite a bit to make it safe. So it won't develop down into the mass Market.

Do road bikes need disc brakes? It's certainly nice to have in the wet. But I can survive on the road without.

 

[Zoiders]

I would be interested to see how glued on tubs behave with hydraulics if you can put that much welly into the braking force, I wouldn't be filled with confidience about them not parting company from the rim.

I would not be suprised to see a hydraulic stand alone drop lever for discs at some stage but it would probably be aimed at the commuting/touring crowd.

If you are really keen you could always track down the next best thing which is the short lived Magura hydraulic drop lever for the rim brakes, they are like rocking horse poo though and change hands for stupid money on occasion.

 

[Cyclopathic]

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?

Also would the addition of hydraulic brakes to road bikes add anything to the performance or experience of riding them? I've never used hydraulic brakes or even disc brakes so I have no idea about the comparative features of them to other systems? I imagine that they are very good for the sorts of riding that they are used for but that the advantage drops off when riding in different conditions. Or to sum up, horses for courses.

 

[lilolee]

The UCI do not allow hydraulics/disk brakes on road bikes used for racing, so I guess manufacturers can't see the point of making different types of frames.

 

[Zoiders]

In the wet and on long descents they are the bees knees, but then again you need the tyre surface area to make that work.

The possible stumbling block for the race crowd is that they offer too much in the way of stopping power for team issue bikes and possibly also for carbon frames and forks, as an option for simple "road" bikes that may get used for everything from Audax to commuting they would be worth a look in simply from a reliablity and ease of set up angle.

Describing a bike as being a "road" bike is a very fuzzy concept.