Road bikes with discs

stu-bim

Are there may road bikes with disc brakes?



Saw this and was wondering if this the way things are going to move or are there many others already and they are just not that popular

Looks stunning

asprilla

They aren't legal for racing, until that happens they will not be the majority of the market.

They are legal for cyclocross racing though and you'd be hard pressed to tell some CX bikes from road bikes.

meanredspider

I don't know that UCI is going to have much influence on most of us. There are more and more road bikes on the market with discs as most road bikes aren't used for UCI-sanctioned events.

I think what's been holding it back is the lack of road-specific brakes - especially hydraulic ones. TRP are doing a lot - the HY-RD is really interesting. Both SRAM and Shimano (and Formula) are introducing hydraulic brifters. Until now, just about everyone used the road-version of BB7s - which is what I have on my Volagi road bike.

Give it 10 years and I think a large proportion of road bikes (40-50%?) will have discs. Roadies are unbelievably conservative so it will be slow.

Sharkyssurfers

yeah i have one, a specialized sectuer sport disc, its ok as a winter commuter as i find the braking is better, but mines ally so quite heavy

asprilla

meanredspider wrote:

Give it 10 years and I think a large proportion of road bikes (40-50%?) will have discs. Roadies are unbelievably conservative so it will be slow.

In 10 years I think it swill be more like 80% with discs. Using my crystal balls I think that in a few years time there will be a sudden explosion in their usage. The irony is that it will be driven by people who don't ride their bikes in the wet or down Alpine descents.

meanredspider

Asprilla wrote:

meanredspider wrote:

Give it 10 years and I think a large proportion of road bikes (40-50%?) will have discs. Roadies are unbelievably conservative so it will be slow.

In 10 years I think it swill be more like 80% with discs. Using my crystal balls I think that in a few years time there will be a sudden explosion in their usage. The irony is that it will be driven by people who don't ride their bikes in the wet or down Alpine descents.

I'd like to think it was - but I am always stunned how slow the road bike world is to take up innovation.

You're probably right about the people riding them - though I'm sure they give more benefit to heavier riders even in benign conditions. And, let's face it, people's weight only seems to be going in one direction.

il_principe

I'm not sure I'd class them as innovation. I think a lot more innovation is required before they find their way onto 80% of road bikes. Especially given roadies obsessions with weight and aero...

TBH I don't really enjoy descending, but even I can happily descend mountains in the wet on 23mm tyres with rim brakes and not feel like I need "better" brakes. IMHO it's a solution looking for a problem, and not even a well thought out solution at that.

veronese68

Asprilla wrote:

meanredspider wrote:

Give it 10 years and I think a large proportion of road bikes (40-50%?) will have discs. Roadies are unbelievably conservative so it will be slow.

In 10 years I think it swill be more like 80% with discs. Using my crystal balls I think that in a few years time there will be a sudden explosion in their usage. The irony is that it will be driven by people who don't ride their bikes in the wet or down Alpine descents.

I think you're probably right. Funny thing being I bought mine for the bad weather braking ability. Now that I've got it I tend to use my old Marin if it's very wet as it has full guards and the tart in me can't fit guards to the green beastie. Come the winter I will have to put guards on it as I want to ride it.

stu-bim

Iam not a roadie at all and thought discs would be really usefull on raleigh rx 2.0

But the biggest problem in wet conditions is stopping bike from sliding even without braking

meanredspider

Il Principe wrote:

IMHO it's a solution looking for a problem, and not even a well thought out solution at that.

Well, it's not really. Pretty much every other brake in the world is a disc brake. That's hardly a solution looking for a problem. That strikes me, at least, that road bike brakes is a problem resisting a solution.

il_principe

meanredspider wrote:

Il Principe wrote:

IMHO it's a solution looking for a problem, and not even a well thought out solution at that.

Well, it's not really. Pretty much every other brake in the world is a disc brake. That's hardly a solution looking for a problem. That strikes me, at least, that road bike brakes is a problem resisting a solution.

I'm not sure what the problem is - given the contact patch of a typical road tyre + desire for weight saving and aero.

meanredspider

Il Principe wrote:

I'm not sure what the problem is - given the contact patch of a typical road tyre + desire for weight saving and aero.

The contact patch is, in many ways, a red herring. On a hard surface, increasing the contact patch just decreases the pressure. The front tyre on a MotoGP bike will brake it from well over 200mph. Where tyre area becomes important in those circumstances is heat management and wear.

For the vast majority of riders, weight saving (of the grammes we're talking about) is irrelevant - especially for bigger riders for whom discs give the most benefit. And for the elite guys, their bikes can already be under UCI weight limits. In theory, at least, disc braked wheels should be able to move some of the rotating mass away from the rim as no allowance needs to be made for brake track wear or heat management.

As for aero differences between rim and disc brakes, I can't imagine it's significant in most circumstances.

What disc brakes do allow you to do is modulate more effectively. They're better in the wet. They also allow you to tune braking with a smaller disc at the rear. You can also choose braking materials simply based upon their ability to brake as they don't need to form part of the wheel. In fact they give all the advantages they give every other braking application for which they are used.

Kieran_Burns

I'm curious, isn't there a difference between sheering and rotational forces being applied the spokes depending on whether you are using rim or disc brakes?

Wrath Rob

I've got one, a custom build Qoroz road bike. I had to go custom as the only other Ti options were all CX bikes but I didn't want CX geometry. Right now, there's not much other choice

jds_1981

My road bike. Riding in winter, brakes don't work well. I give everything a good clean and they work well for a little while then become dire, then I have to give everything a very thorough wash with the hosepipe outside barely above freezing. Become miserable.
My mtb, Riding in winter. Disc brakes work well.

meanredspider

Kieran_Burns wrote:

I'm curious, isn't there a difference between sheering and rotational forces being applied the spokes depending on whether you are using rim or disc brakes?

Dunno - probably - but that's also probably just a difference in how you lace the spokes at the hub so that the load goes through the spoke in tension. In any case, I'd have though the forces were small compared to hitting a bump.

Certainly there doesn't seem to be much difference in total mass of my wheels to any other reasonably good quality alloy wheels. The hubs are slightly larger (for disc attachment) suggesting that the weight has been lost elsewhere.

tgotb

Kieran_Burns wrote:

I'm curious, isn't there a difference between sheering and rotational forces being applied the spokes depending on whether you are using rim or disc brakes?

Yes. On the rear wheel, the forces are just the reverse of those generated by pedalling, so no big deal. On the front wheel there's a new requirement to transfer torque between rim and hub, so radial spokes are out.

One advantage of rim brakes is that, on very long descents, you have a much larger pair of heatsinks to shed energy. It's definitely possible to overheat a disc brake (I've done it MTBing in the Alps), and whilst this is largely an issue of rider skill, there's a big market for idiot-resistant equipment.

For me, one of the big advantages of disk brakes on a heavily-used bike is that your wheels should last almost indefinitely. I've had to rebuild a few commuting wheels after wearing out the rims, and bolting on a new rotor would be much quicker! On the CX, where you don't tend to use the brakes that much, the main advantage is mud clearance.

Headhuunter

There was an interesting article in Cycling + about road bikes with discs. The problems with road bikes having discs is that apparently it's very difficult to run combined brake/shifters on discs (can't remember exactly why) and that disc brakes add a fair amount of weight to the package.

Colnago has released a £9000 road bike with discs and it had to develop its on proprietary brifters. Re weight, it's not that the disc brake mechanisms themselves are heavy it's that the rest of the frame etc has to be beefed up to take the different forces. The fork has to be heavier and stronger, you can't have low spoke count, lightweight wheels as a lot more stress is put through the spokes and the rear triangle has to be strengthened, so any given bike is heavier with discs which is not good when you're racing or doing any kind of competition event...

meanredspider

TGOTB wrote:

[
One advantage of rim brakes is that, on very long descents, you have a much larger pair of heatsinks to shed energy. It's definitely possible to overheat a disc brake (I've done it MTBing in the Alps), and whilst this is largely an issue of rider skill, there's a big market for idiot-resistant equipment.

Conversely, I've seen in the US, at least, they've started to ban carbon wheels on exactly these types of rides because of catastrophic failure of the rims (probably more catastrophic than brake fade). In truth, nothing is idiot-proof...

pitchshifter

Look at the state of them shifters... They could poke someone's eye out!

lostboysaint

Asprilla wrote:

meanredspider wrote:

Give it 10 years and I think a large proportion of road bikes (40-50%?) will have discs. Roadies are unbelievably conservative so it will be slow.

In 10 years I think it swill be more like 80% with discs. Using my crystal balls I think that in a few years time there will be a sudden explosion in their usage. The irony is that it will be driven by people who don't ride their bikes in the wet or down Alpine descents.

That.

tetm

pitchshifter wrote:

Look at the state of them shifters... They could poke someone's eye out!

^ this.

Every time I see the SRAM hydraulic shifters I just see this:

meanredspider

Headhuunter wrote:

There was an interesting article in Cycling + about road bikes with discs. The problems with road bikes having discs is that apparently it's very difficult to run combined brake/shifters on discs (can't remember exactly why) and that disc brakes add a fair amount of weight to the package.

Colnago has released a £9000 road bike with discs and it had to develop its on proprietary brifters. Re weight, it's not that the disc brake mechanisms themselves are heavy it's that the rest of the frame etc has to be beefed up to take the different forces. The fork has to be heavier and stronger, you can't have low spoke count, lightweight wheels as a lot more stress is put through the spokes and the rear triangle has to be strengthened, so any given bike is heavier with discs which is not good when you're racing or doing any kind of competition event...

I can only imagine that's to do with hydraulics on the brakes/shifters. Electronic shifting I'm sure would solve that. Certainly no issues on my bike.

As I've said above, in a world where we can put together a bike under UCI weight limits, I don't think weight is an issue. Let's face it, all we have so far is a 10 year old bastardised mechanical MTB brake in the BB7 as pretty much the benchmark. My Volagi is hardly a heavyweight at 7.5kg. The frame is only 150g or so heavier than the Scott CR1 SL (the retail price of the Scott frame is almost that of the entire Volagi).

Headhuunter

meanredspider wrote:

Headhuunter wrote:

There was an interesting article in Cycling + about road bikes with discs. The problems with road bikes having discs is that apparently it's very difficult to run combined brake/shifters on discs (can't remember exactly why) and that disc brakes add a fair amount of weight to the package.

Colnago has released a £9000 road bike with discs and it had to develop its on proprietary brifters. Re weight, it's not that the disc brake mechanisms themselves are heavy it's that the rest of the frame etc has to be beefed up to take the different forces. The fork has to be heavier and stronger, you can't have low spoke count, lightweight wheels as a lot more stress is put through the spokes and the rear triangle has to be strengthened, so any given bike is heavier with discs which is not good when you're racing or doing any kind of competition event...

I can only imagine that's to do with hydraulics on the brakes/shifters. Electronic shifting I'm sure would solve that. Certainly no issues on my bike.

As I've said above, in a world where we can put together a bike under UCI weight limits, I don't think weight is an issue. Let's face it, all we have so far is a 10 year old bastardised mechanical MTB brake in the BB7 as pretty much the benchmark. My Volagi is hardly a heavyweight at 7.5kg. The frame is only 150g or so heavier than the Scott CR1 SL (the retail price of the Scott frame is almost that of the entire Volagi).

I can't remember the exact reason Colnago had designed their own brifter but it was explained fully in the article on C+... I'm sure eventually it'll be possible to bring the weight of disc brake equipped road bikes down by shaving weight off other compnonents but if you used those components on a standard bike, the weight would be even lower. Even the £9000 Colnago isn't at the UCI weight limitation...

meanredspider

Headhuunter wrote:

.
I can't remember the exact reason Colnago had designed their own brifter but it was explained fully in the article on C+... I'm sure eventually it'll be possible to bring the weight of disc brake equipped road bikes down by shaving weight off other compnonents but if you used those components on a standard bike, the weight would be even lower. Even the £9000 Colnago isn't at the UCI weight limitation...

http://www.bikeradar.com/road/gear/cate ... c-13-47194

The frameset is 150g heavier and bloody expensive. I can't imagine making your own hydraulic brifters is a cheap exercise either. I see that they have used Di2 too. They seem to be pretty positive about its ability to accelerate and corner.

Wrath Rob

If you're that fussed about weight then lose a kilo or 2 of body fat. Most of us could benefit more from that than by shaving a few 100's grams off our bike

Some interesting insight into where SRAM is going here

BTW, Bianchi as joined the party too. As have Enigma

Article on Road.cc about aero benefits, or lack of, for disc brakes.

meanredspider

Wrath Rob wrote:

If you're that fussed about weight then lose a kilo or 2 of body fat. Most of us could benefit more from that than by shaving a few 100's grams off our bike

Some interesting insight into where SRAM is going here

BTW, Bianchi as joined the party too. As have Enigma

Article on Road.cc about aero benefits, or lack of, for disc brakes.

Agree entirely about the weight.

It's a pretty poor aero test. Certainly, as tested, the discs are less aero BUT, without a rider, the results are a nonsense. Why didn't they just put the brakes into the wind tunnel?

The disc brake might even improve the airflow around the rider (of course, it might not too - the point is we don't know). Much of the bells and whistles on the front of an F1 car are to improve flow over the rest of the car.

Equally, the difference in results, once the rider is included, might be negligible - much like the weight difference.

Stevo_666

stu-bim wrote:

I've been commuting on a flat barred road bike with hydraulic disc brakes for nearly 4 years now and it works very well - I've only changed the pads twice and the brake fluid once and I'm still on the original discs (and wheels). Coming home in the wet tonight and needing to stop quickly coming down a hill just reminded me why it's such a good thing.

Just waiting for 'real' road bikes to catch up and I'll get one - looks like it's only a matter of time now.

Pic quoted because that Bianchi is absolutely ferkin gorgeous - I WANT one!

Headhuunter

Wrath Rob wrote:

If you're that fussed about weight then lose a kilo or 2 of body fat. Most of us could benefit more from that than by shaving a few 100's grams off our bike

Some interesting insight into where SRAM is going here

BTW, Bianchi as joined the party too. As have Enigma

Article on Road.cc about aero benefits, or lack of, for disc brakes.

It's more than a few hundred grammes! The colnago weighs 7.2, for a 10000 quid bike that's at least a kilo overweight

meanredspider

Headhuunter wrote:

Wrath Rob wrote:

If you're that fussed about weight then lose a kilo or 2 of body fat. Most of us could benefit more from that than by shaving a few 100's grams off our bike

Some interesting insight into where SRAM is going here

BTW, Bianchi as joined the party too. As have Enigma

Article on Road.cc about aero benefits, or lack of, for disc brakes.

It's more than a few hundred grammes! The colnago weighs 7.2, for a 10000 quid bike that's at least a kilo overweight

The frameset weighs only 150g more for the disc version than the regular version. If it's overweight, that's only fractionally due to the brakes

Headhuunter

meanredspider wrote:

Headhuunter wrote:

Wrath Rob wrote:

If you're that fussed about weight then lose a kilo or 2 of body fat. Most of us could benefit more from that than by shaving a few 100's grams off our bike

Some interesting insight into where SRAM is going here

BTW, Bianchi as joined the party too. As have Enigma

Article on Road.cc about aero benefits, or lack of, for disc brakes.

It's more than a few hundred grammes! The colnago weighs 7.2, for a 10000 quid bike that's at least a kilo overweight

The frameset weighs only 150g more for the disc version than the regular version. If it's overweight, that's only fractionally due to the brakes

Yes but the extra weight comes in the wheels too... If you use discs, the wheels have to be considerably beefed up to take the strain of braking near the centre... Whichever way you slice it 7.2kg is pretty damn heavy for a top flight race machine costing £10k