Viewpoint of discs on road bikes

mikeyj28

Hi all

I am coming to the road from a relatively good background in MTB XC racing and I still enjoy riding my MTB now.
I am seeing quite a few high end non cyclocross bikes that are having discs.

Is this the future of brakes for road bikes or is it that some people feel more comfortable with them over standard rim brakes?

What are your views on this too or your experiences? I am finding it hard to adjust at the moment but hat is due to me being used to discs on my HT and full suss race bikes.

meanredspider

Not really sure what you're finding hard to adjust to - it's not clear clear in what you've written.

I've been riding road discs on my Volagi for nearly 4 years now and they've been everything I hoped for. They work in the wet, you have more control (more progressive - better modulation), you don't need to worry about the rims either in crappy conditions or on alpine descents. If they have a downside it's that they are slightly heavier - a small price to pay.

Generally I see the opinion swinging towards discs. Nearly everybody that has tried them loves them and most people that are against them haven't tried them. I'm not bothered that I don't have them on the Foil because I ride that in N Holland which is totally flat and I almost never need to brake.

Pigtail

They're definitely coming. Once we see them in competitive road racing that will burst the dam. In the meantime technology, compatibility and wheels will all improve and tempt more and more people.

Having said that, I've just spent money that I think I'm unlikely ever to match again, on a road bike with rim brakes.

ugo.santalucia

If you posted this thread in 2011 then maybe it would make sense, but in 2015 disc brakes on road bikes are very much a reality, with virtually every manufacturer offering at least one or two options and a few of them offering more disc braked bikes than rim braked bikes. It is easy to see the tipping point in the next 2-3 years, when more bikes with disc brakes will be sold than without. The recent introduction of hydraulic brake levers means rim calipers are now a thing of the past, kept alive by the stubborn resolution of the UCI to stick to rim brakes for racing.
There is a sense in the madness, in that rim brakes are better for racing, but 99% of those who buy a bike don't race and this is something the UCI will have to come to terms with and eventually concede to the market pressure.

gweeds

There is a strong rumour that we'll see them on at least one team in this year's Tour of Flanders as a test.

Seems a but high profile to me but who knows with the UCI.

tangled_metal

I read something, somewhere about disc brake on road bikes close to being accepted on pro teams. IIRC the manufacturers are geared up to delivering disc road bikes, the designs are there ready. The pro cyclists are ready to accept them, indeed the article even said that some actually want it (something about disc brakes being better for the downhills and allowing them to push even more on the downhill sections). The teams are ready. It almost feels like the only thing stopping it is being the first to do so. The first time a top or second tier team brings them in I reckon it will happen quicker and quicker. This is kind of the piece I read, which IIRC was from an interview with a bike designer with a company that makes good road bikes (and sponsors or supplies teams). Wish I could remember the details.

As far as us mortals go I am not a racing snake, I will never compete (it is not my reason to ride). That means my bike will never be the ultimate design where the extra weight of disc brakes will make any real difference. Indeed if I was truly worried about weight I would shed a bit from my middle, take my mudguards off, remove my rack and change my wheels to a lighter set.

My riding is about enjoying the experience of the ride. It is about being in nice places on my bike and often with the family. It is touring, day rides and commuting. All of those things out of just one bike. That bike has the best bits on it I could afford when I got it (the best bike I had the money for IMHO or it will be when I get it). It will have disc brakes on it. I have a road bike that I have not ridden since I went down a steep hill with sharp bends with rim brakes that got the rim so hot I could not even touch it. That was in Cumbria but not even on the big hills, but one on the edges. Admitedly my brakes did need a bit of maintenance such as the pads were close to their end of reasonable life but they were well adjusted and my wheels had just been trued.

Do you have problems getting used to the performance difference between your MTB disc brakes and your road rim brakes? You should have seen me switch the other way. Trust me the first time you brake with your first ever disc brakes on a downhill like you were using your road rim brakes you will know it is more painful to adjust the other way. To say I connected with my steerer is an understatement. I am not kidding, I was not expecting the stopping power compared to my admittedly poor rim brakes. Add to that the wide flat bar that I was getting used to and I made a right idiot of myself.

ugo.santalucia

I've just noticed that Van der Poel won the CX Worlds on disc brakes.... I stand to be corrected but this is a first. It is a milestone, as most "old guard" athletes are on cantis and seeing a 20 year old riding discs and winning convincingly might clear the stigma and help them make their way into road racing as well.

mercia_man

Disc brakes on road bikes are here but are still evolving. Hydraulic brake levers operating fixed twin piston calipers are a big leap forward from cable-operated discs and sliding calipers (just as they were years ago in the motorbike world) and I feel sure they will dominate the higher end road bike market. Axle standards are still a mish-mash - and this is one of the issues affecting the potential future take-up of discs in road racing.

I think eventually road manufacturers will follow the lead of mountain bikes in adopting through-axle technology for greater security, safety, stiffness and pad/rotor alignment, as well as avoiding US legal claims from riders whose quick releases have allowed disc wheels to slip out of open fork dropouts. Focus, Colnago, Trek, Scott and Rose are going for through-axles, others like Giant haven't yet.

ugo.santalucia

Mercia Man wrote:

Axle standards are still a mish-mash - and this is one of the issues affecting the potential future take-up of discs in road racing.

Not really... hubs like Novatec and Hope come with all the possible end caps to accomodate every existing standard... if you change standard, you just change the end caps (and occasionally axle), 5 minutes job

Mccaria

My understanding is that the UCI is concerned about allowing disc brakes in on all events because of the different braking distances between disc and rim brakes which could increase the chance of crashes in bunch situations. I thought they were going to trial discs in some of the flatter races such as Paris Roubaix. For the hilly courses it seems as though it is going to have to be everyone on rim brakes or everyone on discs.

I would be very interested in a disc brake set up with a pair of light carbon clinchers for the mountains, but would like to see what standard (if any) is going to emerge for axle type before spending heavily.

mercia_man

ugo.santalucia wrote:

Mercia Man wrote:

Axle standards are still a mish-mash - and this is one of the issues affecting the potential future take-up of discs in road racing.

Not really... hubs like Novatec and Hope come with all the possible end caps to accomodate every existing standard... if you change standard, you just change the end caps (and occasionally axle), 5 minutes job

What I mean is not every manufacturer agrees on what standard to use - with the result that neutral service people in road races are reportedly worried that they will not be able to carry the variety of wheels needed, thus making quick wheel changes in the heat of a race problematical.

ugo.santalucia

Mccaria wrote:

I would be very interested in a disc brake set up with a pair of light carbon clinchers for the mountains, but would like to see what standard (if any) is going to emerge for axle type before spending heavily.

As above, irrelevant, just go for Hope or Novatec hubs

ugo.santalucia

Mercia Man wrote:

What I mean is not every manufacturer agrees on what standard to use - with the result that neutral service people in road races are reportedly worried that they will not be able to carry the variety of wheels needed, thus making quick wheel changes in the heat of a race problematical.

Whan was the last time you saw the Mavic (or other) service carry out a wheel change that turned out to be decisive for the race outcome? It's a genuine question, because I can't remember

Simon_Rhino

ugo.santalucia wrote:

I've just noticed that Van der Poel won the CX Worlds on disc brakes.... I stand to be corrected but this is a first. It is a milestone, as most "old guard" athletes are on cantis and seeing a 20 year old riding discs and winning convincingly might clear the stigma and help them make their way into road racing as well.

I think you're right for a 'Mens Worlds' (and PFP rode discs in the womens too) but Lars van der Haar won in the World Cup in 2013 with discs and Marianne Vos hasn't done too badly in recent years with hers either

mercia_man

ugo.santalucia wrote:

Mercia Man wrote:

What I mean is not every manufacturer agrees on what standard to use - with the result that neutral service people in road races are reportedly worried that they will not be able to carry the variety of wheels needed, thus making quick wheel changes in the heat of a race problematical.

Whan was the last time you saw the Mavic (or other) service carry out a wheel change that turned out to be decisive for the race outcome? It's a genuine question, because I can't remember

No I can't remember, either. But this is one of the objections that have reportedly been raised in the UCI debate on whether to allow discs. Along with concerns such as riders being injured on hot rotors in crashes and potential dangers if some riders are on more powerful discs and some on less powerful calipers. I'm not saying these issues are unsurmountable. But clearly they need to be addressed in the decision-making process.

ugo.santalucia

Mercia Man wrote:

No I can't remember, either. But this is one of the objections that have reportedly been raised in the UCI debate on whether to allow discs. Along with concerns such as riders being injured on hot rotors in crashes and potential dangers if some riders are on more powerful discs and some on less powerful calipers. I'm not saying these issues are unsurmountable. But clearly they need to be addressed in the decision-making process.

They are petty points though... as chainrings are just as dangerous as discs, maybe not hot, but I think it's a non issue in a world where you can go down at 60 mph with only a foam helmet as protection... I wouldn't worry too much about a hot disc.

The thing is Shimano has invested in the technology and so has SRAM... Campagnolo only do road race equipment and apparently they are coming out with something in 2016 or soon after. So there is your answer...

tangled_metal

Do existing rim brakes not have a variance in the stopping distance / stopping performance? Surely there are variables in rim brakes that mean a bunch could have riders with the ability to stop quicker than others. If this is an issue with disc brakes then is there not an issue with rim brakes too?

This is a serious question not a point being made. I have never raced so have no first hand idea of the bunch dynamics and the importance/likelihood of uniformity of braking performance.

ugo.santalucia

Tangled Metal wrote:

Do existing rim brakes not have a variance in the stopping distance / stopping performance? Surely there are variables in rim brakes that mean a bunch could have riders with the ability to stop quicker than others. If this is an issue with disc brakes then is there not an issue with rim brakes too?

This is a serious question not a point being made. I have never raced so have no first hand idea of the bunch dynamics and the importance/likelihood of uniformity of braking performance.

I think it's a complete non issue... every racer worth his money will be able to brake and ride according to the conditions... if it's wet and he's on rim calipers, he'll be a bit more careful and keep more distance... there is no magic power in hydraulic brakes, they are just a bit safer when it's wet

tangled_metal

That is what I thought. Riders can assess stopping just as well as they can assess their own reflexes which probably has a bigger affect on variance in stopping performance. Complete non-issue and excuse to drag their feet. Are UCI known for dragging their feet on things like rules and accepting new tech?!!

Mccaria

Ugo,

My post crossed with yours so didn't see your bit about Hope and Novatec. For me one of the attractions of a disc brake would be to build a lightweight carbon clincher that would work well in the Alps etc. I realise this wont necessarily be a big part of the disc market, but if I am shelling out a reasonably large sum for a disc frame and disc wheels I want them to last a while (lesson learnt from 7090 Di2 !).

TM, yes rim brakes can be set up differently and for instance wheel rims with carbon surfaces grip at different rates to alloy which must have been an issue when carbon rims first came out and some pros were riding with carbon and some with alloy rims. The concern seems to be both the braking distance and how the brake works as the disc tends to grab much quicker than a rim brake, so the immediate reduction in speed differs materially from a rim brake. When riding is close proximity in a bunched peloton riders will not necessarily be able to choose distances from other riders

ugo.santalucia

Mccaria wrote:

Ugo,

My post crossed with yours so didn't see your bit about Hope and Novatec. For me one of the attractions of a disc brake would be to build a lightweight carbon clincher that would work well in the Alps etc. I realise this wont necessarily be a big part of the disc market, but if I am shelling out a reasonably large sum for a disc frame and disc wheels I want them to last a while (lesson learnt from 7090 Di2 !).

TM, yes rim brakes can be set up differently and for instance wheel rims with carbon surfaces grip at different rates to alloy which must have been an issue when carbon rims first came out and some pros were riding with carbon and some with alloy rims. The concern seems to be both the braking distance and how the brake works as the disc tends to grab much quicker than a rim brake, so the immediate reduction in speed differs materially from a rim brake. When riding is close proximity in a bunched peloton riders will not necessarily be able to choose distances from other riders

MTB have all these standards for a long while and manufacturers that do MTB hubs have come out with designs where it's all interchangeable. Just shy away from Shimano hubs and other cup and cone designs that might not be interchangeable between standards. Hope or Novatec would be my bet.

Mccaria

Thanks Ugo,
Also I think it depends which way the frame builders go to see whether a standard emerges. I would hate to see axles go the way of the BB on road frames, but that would be a whole different thread !!

apreading

Are they all starting to adopt 135mm rear hubs now? I thought Specialized came up with a (currently) proprietary 130mm disc hub but you could convert the bike in some way? Would be great if road bikes and MTB could adopt the same basic geometry and then axle standards and all hubs were usable in all bikes...!

ugo.santalucia

Based on the current market, I would not buy a disc bike with 130 mm rear... you end up stuck with proprietary parts and all that nonsense.

meanredspider

My Volagi has 130mm rear hub. They've since moved to 135mm on all their bikes.

veronese68

Some MTB have started to go 142mm bolt through rear. But there are so many bikes with 135mm QR, many still being built it will not go away so availability will not be an issue. The Novatec 771 I got for my MTB build I ordered with 15mm bolt through caps extra, the hub came with QR fitted. It's very easy to swap the caps, just drop the wheel out and pull the cap off and push the new one in with a bit of rubber grease on the o ring seals. No problem at all, assuming I remember where I left the end caps.

markhewitt1978

IMO the UCI should just let the teams do what they like in this area. Lets see some innovation in the bikes being races in pro races. Yes; it may cause some issues with neutral service, but that's not something the UCI needs to get involved with. If a team decides the advantages of running discs outweigh problems with bike service then that has to be their own choice?

ai_1

markhewitt1978 wrote:

IMO the UCI should just let the teams do what they like in this area. Lets see some innovation in the bikes being races in pro races. Yes; it may cause some issues with neutral service, but that's not something the UCI needs to get involved with. If a team decides the advantages of running discs outweigh problems with bike service then that has to be their own choice?

There may be some legitimate safety concerns with regard different bikes having very different braking performance in a peleton. It's reasonable to suggest it could cause problems with guys on rim brakes going into the back of guys with discs in certain situations but the fact that this is a legitimate issue just goes to demonstrate that discs do perform significantly better than rim brakes.

markhewitt1978

My bet would be that if the UCI were to say right now that from January 2016 teams would have a free choice, I would expect the issue of braking performance would be mute as everyone would be running discs.

Weight is an issue, but is it really an issue when most teams bikes are built under the minimum weight limit anyway?

ugo.santalucia

Ai_1 wrote:

There may be some legitimate safety concerns with regard different bikes having very different braking performance in a peloton. It's reasonable to suggest it could cause problems with guys on rim brakes going into the back of guys with discs in certain situations but the fact that this is a legitimate issue just goes to demonstrate that discs do perform significantly better than rim brakes.

It's not legitimate... it is nonsense. In the same league one would have to ban all wheels with alloy track, as they perform better in the wet... or better brake pads

ai_1

ugo.santalucia wrote:

Ai_1 wrote:

There may be some legitimate safety concerns with regard different bikes having very different braking performance in a peloton. It's reasonable to suggest it could cause problems with guys on rim brakes going into the back of guys with discs in certain situations but the fact that this is a legitimate issue just goes to demonstrate that discs do perform significantly better than rim brakes.

It's not legitimate... it is nonsense. In the same league one would have to ban all wheels with alloy track, as they perform better in the wet... or better brake pads

Fair point