[Closed] Road discs, do we wait a while?

I have bb5s on my cross bike, and for weight and asthetics I wouldn't get them on my road bike.

until we have genuine lightweight hydro road discs I wouldn't buy a bike with them.

Dunno, but do you think Winstanleys really mean availability 2-7 days on these Shimano CX discs?

[url= http://www.winstanleysbikes.co.uk/product/51912/Shimano_Ultegra_BRCX75_Disc_Brake_Caliper ]Winstanleys CX75[/url]

Might take a punt on them rather than BB7 for next build.

I don't see it at the very top end any time soon,if ever (within reason-digital laser disc brakes aside).

. One of the reasons to buy a good carbon frame is that they are tuned as they are built. Offering the rider stiffness and comfort in the right places and right quantities.
If changes are being made to accommodate discs will we lose ride quality?

The same question applies to wheels. Will low spokes cope?

You believe that marketing guff?

Look at mtb frames - did the ride change when they all got discs? As for wheels, don't forget that pedalling and braking already put stress on them, and no one's going to release products that aren't tested into the litigious US market.

MLC Madison are listing them on their B2B site, don't know about stock tho.

Ive used some BR M415 and they have a good feel to them, but they were bulky 230g:
[img] [/img]

I went back to BB7s and they come in at 160g
[img] [/img]

The CX75 will alledgedly be "156g"

I just bought a new road bike this year
By the time I want another one [in 3 or 4 years] it'll be wall to wall electronic shifting, disc braked bikes.
You'll can really feel the momentum building now and it'll just rush in to every line up in the next months

That's not guff at all. A good frame feels different even when an oaf like me is racing it.
And I'm sure the disc frames will be strong enough, no questions about it.

I can't wait to see what comes out next year.

Surly the will be some discs in the tour this year? I hope to see at least 1 team running them.

I fail to see the problem current brakes have that disks will improve.

Seems an awful faff to me.

Surly to have a bike in the Tdf?..I do hope so.

[img] http://surlybikes.com/uploads/bikes/disctrucker.jp g" target="_blank">http://surlybikes.com/uploads/bikes/disctrucker.jp g"/> &sa=X&ei=mrFgUOmeMoHN0QWkg4GQDg&ved=0CAoQ8wc&usg=AFQjCNGrJir_1k-OHVQjJtS-j3VQYnyiBQ[/img]

Are we still doing this? Disc brakes are, apparently, ok for MTBs, Cross, Commuters and Tourers and yet they are somehow "unproven" when applied to "road" bikes.....

IIRC the UCI hasn't sanctioned discs for road yet? So no teams doing discs in the near future at least.

This isn't about the qualities of disc brakes. It's about the marriage of strength required to run discs and the performance requirements of a top end racing frame.

I couldn't say for certain, but I bet more goes into the design on the rear end on a pro road race machine to get as much out of the riders input, than goes into a MTB frame.

Personally I still feel almost thankful for the discs on my MTB, but I've never felt the need for more braking on my race bikes. In the wet on the hardest of descents I worry more about my tyres keeping me upright.

Surly the will be some discs in the tour this year? I hope to see at least 1 team running them.

Not seen that many in the cross races this season yet. And what with roadies and their favorite wheels.

MLC Madison are listing them on their B2B site, don't know about stock tho.

Madison are showing 12th Oct as expected delivery

That Shimano brake looks interesting. I've been using BB7s for a long time on the work bike, but the materials tend to corrode easily in winter, so I would like to see how the Shimano construction and performance compares.

As others have pointed out, one of the current issues for road racing applications will be race service. Would you be able to guarantee the alignment when swapping discs, or adjust them quickly enough? Neutral service also becomes trickier with more permutations of wheel type and component manufacturer. You need to beat rim brakes on weight as well, because performance is not currently a limiter.

oldgit - Member
That's not guff at all. A good frame feels different even when an oaf like me is racing it.

I don't disagree - but you imply carbon frames are made like a bespoke suit. All high end frames have butting/hydroforming etc claimed to tailor the ride. In any event your own argument makes discs easy to add to a carbon frame without affecting the ride much (and a bit of strengthening around the LH dropout will have **** all effect on ride quality).

I'm buying this canyon as soon as it becomes available.. (2014??)

http://www.bikerumor.com/2012/09/12/canyon-teases-disc-brake-road-bike-plus-new-29er-mountain-bikes-more/

Hmmm. Then there's the wheel issue. I don't think you can run radial spokes can you? Plus the braking surface of a rim is an integral part of the wheels structure, so I guess you could lose the surface but you'd need to retain the strength.
Then there's the heat issue, long long drags would be a killer wouldn't they.

And back to the frames. Could you just slap disc calipers on the current crop? probably not. So while I like the idea it seems a lot of changes would have to be made to kit that doesn't need improving just to take discs.

Wheels - they managed on mtbs OK I think?

dragging - see other threads, I CBA going through that again.

Hilarious luddittes...

No don't wait, do it now.

Fugly and pointless.

Still there are a lot of bikes around that fit that category.

Was discussing this with a roadie mate at the weekend - think Colnago have a disc equipped road bike on show at the moment, so they may be available in a year or two to purchase at the top end BUT only if the UCI permit them on pro bikes will they appear on your "average" £1-£1.5 sportive bike that us MAMILs like to go for

Discs currently aren't allowed by the UCI in road racing, people like to ride what the pro riders ride so until the UCI change their position I can't see discs becoming the de facto standard on road bikes.

From what I understand the main concern is nothing to do with performance but how safe they are in closely packed peletons where crashes with large numbers of riders are pretty frequent.

I'm surprised the bike companies have been so slow on this. Plenty have disc CX frames, so the frame tech is there , but very few have road frames ready. Which is all the more surprising given the enormous number of std. carbon road frames out there that all look the same. Have they not heard of a USP...

Volagi - available but with a few snags
Colnago - on show, and nice, but silly prices and lecky only!
Canyon - proto only
Time - proto only

If Boardman could get his finger out and get a disc roadie to market, based on the AiR or SLR frame, they'd have a proper rush on their hands IMO.

Discs would I use them now?
On the crosser yes. I'm good with canti's but they're still a faff.
On the training bikes yes. Too many winter days with cold hands and pads that wear in a day and usually at the top of the worst descents.
On the race bike, for my racing, no.

Is there real demand for this? Absolutely needed on MTB where you need the power and feel of discs, and rims get horribly covered in cack. On a road race bike though... I really can't see the need. I'll probably eat my words in a few years time when I get to try it.

I'm surprised the bike companies have been so slow on this. Plenty have disc CX frames, so the frame tech is there

It's not though. The CX frames are beefy and just carbon doing a job. Top flight race frames are designed, engineered to get the best out of a racers input and be comfortable as well. They talk about the direction of the weave and it's lay up. Well now we are asking the frame builders to keep all that, but at the same time build in the ability to handle the stresses of discs.

midlifecrashes - Member

Dunno, but do you think Winstanleys really mean availability 2-7 days on these Shimano CX discs?

It's Winstanleys so... Might be 2-7 days, might be 2 years.

Back to the Future.

Does anyone have time machine so we can just replay all the arguments about disks on motorbikes?

druid I'm not saying they ain't great stoppers.
The thing with race bikes is that they have been getting lighter and lighter over the years with forward momentum being the only thing that matters. So you have these minimalistic machines that suddenly now need to cope with discs.
I'm not into motorbikes, but I'd imagine you could add and subtract weight far easier, add a strut here remove a pipe there? There just doesn't seem to be anywhere left on a race bike to do this.

The big benefit of discs on a road bike is little to do with braking performance but it's benefits in wheel and rim design if the rims don't have the constraint of needing a braking surface.

It's already possible to buy/build a bike to come in below the UCI minimum weight. If any beefing up is required there is scope to do so.

The big benefit of discs on a road bike is little to do with braking performance but it's benefits in wheel and rim design if the rims don't have the constraint of needing a braking surface.

Whilst they wont need a braking surface they'll still need to be reinforced or they'd be too weak. It still needs to be strong. You could probably go far crazier designing a wheel that didn't have to incorporate a disc and disc hub. Less and lighter spokes for a start.

I've been using them on my Kinesis Tripster for ages and they've been great, especially on days like today when there was a complete downpour. For pure racing though, well, you can't even enter as they're still banned so forget it!

I did worry they might not be up to long alpine descents with the small 160mm rotors, but I went to the alps a few weeks ago and they were fine with no fade or anything. Here's some pics from the top...

[img] [/img]

[img] [/img]

it will happen within the next few years - the UCI will watch what happens with 'cross bikes, then will introduce them for TT bikes (where you don't change a wheel, you swap bikes for the protour) and then after a few years the parts will be on the shelf. They just need to agree on a standard rotor size and a bit of lateral thinking about the best way for a quick change

As I understand it, it's not that the UCI are against, it's simply that no-one has put any forward for approval yet. And no-one will until they got something really good. We haven't seen anything really good yet, but it's surely not far away.

oldgit - Member
The CX frames are beefy and just carbon doing a job. Top flight race frames are designed, engineered to get the best out of a racers input and be comfortable as well. They talk about the direction of the weave and it's lay up. Well now we are asking the frame builders to keep all that, but at the same time build in the ability to handle the stresses of discs.

Do you know the difference in weight between top road, cx and mtb frames?

Super Six = 800gm...Scott HT = 1kg?

The differences are not as big as you think.

For those calling us road disc sceptics luddites, maybe you can explain to me exactly what the big advantage is? I get the advantage of discs on MTB and CX bikes (I'd not get a CX bike with cantis if buying now), but the reasons they're a good idea for them don't really apply in the same way for road race bikes.

no one's going to release products that aren't tested into the litigious US market.

Ah, that's why there are so many lethal product failures akin to bike wheels collapsing at high speeds?

cynic-al - Member

Ah, that's why there are so many lethal product failures akin to bike wheels collapsing at high speeds?

Ford Pinto... Ford famously did the cost-benefit analysis and decided it was cheaper to have the cars burst into flames and pay out on lawsuits, than it was to fix the car ($11 per car!)

40 years ago?

The big benefit of discs on a road bike is little to do with braking performance but it's benefits in wheel and rim design if the rims don't have the constraint of needing a braking surface.

I'd agree with this and extend it further... Packaged correctly, a disc brake setup could significantly aid in making a road bike more aero. Wheels without braking surfaces would be more aero, stronger and lighter for a given rim width/depth. OK, so you can't build em radially, but 24 lightweight aero spokes crossed 2x on both sides of each wheel would still suffice. Disc brakes would also get rid of the brake caliper from the air flow, and could also be better designed to sit out of the way of any airflow behind the fork leg up front and integrated into the stays on the rear of the bike.

As has also been mentioned, rim brakes currently aren't a limiting factor on the performance front braking wise. Well that may be the case, but where's all that heat build up going? Into the rim, with the potential to cause a blow out through excessive heat build up. Disc brakes will be inherently safer because of their ability to deal with the heat better. Given that the average 23c tyre isn't going to grip as well as a 2.5" Super Tacky Minion either, road disc brakes would have to be made small enough so that they weren't grabby or excessively powerful anyway, so in fact you might find a suitable road disc brake was actually less powerful in back to back tests than a top of the line caliper brake currently available. But the other benefits could potentially outweigh the drawbacks of less power.

All the above said, if disc brakes were going to catch on properly on road bikes, they've had plenty of time to do so! The XC racing world took its sweet time to fully embrace discs, CX bikes were available with discs a long time ago (I remember seeing them in the shops with discs circa 2001), but we're where we are with disc brakes on road bikes today because maybe there isn't really enough benefit to bother? Perhaps what you gain in one hand, you'd lose in the other so to speak, by fitting a disc...

That Canyon doesn't half look cool though! And that for me would be reason enough to buy one with discs...

I was more vehemently against disc on road bikes until I bought some new Shimano SLX for my MTB, and most of my anti disc brake arguments evaporated.

BUT (and maybe Ribena can answer this after his Alpine descents) can anyone else honestly say they never end up with rubbing discs and or slightly warped rotors? I'm pretty sure, actual 'dings' to the rotor aside, that they seem to warp with general use. I've gotten over it on my MTB, but the constant scuffing and ting ting ting of a warped or misaligned disc would do my head in on a road bike, I'd prefer the 'disadvantages' of a calliper brake, at least wheels can be more accurately trued that rotors...

I guess at the end of the day though, it would be much easier for road bike manufacturers to retain the calliper brake mountings? Not like MTBs where they stick out and 'ruin the lines' in magazine speak. 🙄

I have no problem at all with road discs and would love to [ad probably will] have them.
But ..... given that Colnago have said that their disc braked C59's stopping distance is 52% less than the rim braked model, I'd be a bit worried in group rides with that sort of disparity - if indeed it is an accurate figure.

But if you can stop 52% quicker than the guy in front during a race, why would you if you're racing?

As for the guy behind, you'd have pulled away approaching the corner because he'd have started braking sooner.

When I first got discs, non of my v-Brake equipped mates rear ended me.

jota180 - Member
I have no problem at all with road discs and would love to [ad probably will] have them.
But ..... given that Colnago have said that their disc braked C59's stopping distance is 52% less than the rim braked model, I'd be a bit worried in group rides with that sort of disparity - if indeed it is an accurate figure.

Accepting that 52% for the moment (and I'm not sure that I believe it) I'd expect a similar variance between well set up and poorly adjusted rim brakes

Accepting that 52% for the moment (and I'm not sure that I believe it) I'd expect a similar variance between well set up and poorly adjusted rim brakes

So if you were now in a mixed disc/rim brake group, the difference between the best disc and worst rim will be huge? - again, accepting the 52% figure

given that Colnago have said that their disc braked C59's stopping distance is 52% less than the rim braked model, I'd be a bit worried in group rides with that sort of disparity - if indeed it is an accurate figure.

Say what!

Going back to the bit up there, is heat build up an issue on 700c rims which are effectively huge discs? Whilst we know heat build up on road discs are.
And TT bikes, do they even need them. Surely not for stopping. I'd have thought fully intergrated was the way forward there. And surely a full disc wheel would be less aero with a disc added?

As for the guy behind, you'd have pulled away approaching the corner because he'd have started braking sooner.

When I first got discs, non of my v-Brake equipped mates rear ended me.

It's not the corners though, it's those little incidents where people brake on instinct, when you're within a couple of feet of each other it could get interesting.
I don't think I regularly sit that close to a group of mates at speed on a MTB

until shimano/sram/campag release disc compatible brake levers it is a pointless waste of time discussing discs and whether they will take off. The simple answer is they won't.

Why are mtb rims relatively unchanged? (Bar the aero aspect)

Why aren't track rims radically different?

Packaged correctly, a disc brake setup could significantly aid in making a road bike more aero. Wheels without braking surfaces would be lemore aero, stronger and lighter for a given rim width/depth.

The change from rim to braking surface on my deep section carbon race wheels is practically unnoticeable I don't see how a wheel with a disc on it will be more aero

couple of feet

more like six inches in some cases.

I also can't help notice that the Colnago is fully rim brake compatable.

This whole road disc thing seems a great idea, especially on my all year round training bikes...I can think of at least one time a year I need more braking? But would I wan't it slapped right now onto a top end Cervelo or SuperSix Evo.

I don't see how a wheel with a disc on it will be more aero

Let alone the larger weightier hubs and extra hoses.

Surely a rim needs added integrity around it's outer area, to hold the tyre and take shock from the road. In a way a braking surface is taking advantage of this need?

No mention yet of the new SRAM red hydraulic discs yet? They are due to be released anytime time soon and a few big companies are waiting for them before releasing their road disc models. They will be here soon!

Was a good article on road.cc (can find it though) about them and the thought was they would help in a crowded peloton especially as wet carbon rims have pretty poor breaking performance even with the most advanced pads.

I don't see how a wheel with a disc on it will be more aero
Let alone the larger weightier hubs and extra hoses.
Surely a rim needs added integrity around it's outer area, to hold the tyre and take shock from the road. In a way a braking surface is taking advantage of this need?

That's not what we've seen on mtbs. Compare old mtb rims to a set of Stans.

I would have thought there would be some advantage to be had in reducing rotational weight.

I don't imagine it'll be an instant, total switch for road pros. Wet days in big mountains will be where they appear first, surely - where potential gains are biggest ?

Salsa are on it this winter with the collosal, a mile munching road bike.

140mm bb7s

I can see discs being an advantage on long wet alpine descents. One benefit is the additional confidence you will have, knowing the brakes will respond instantly... Even if the tyres may still break away 🙂

I am happy with the looks too. One of these is already in my imaginary dream bike shed.

[img] [/img]

Was a good article on road.cc (can find it though)

[url= http://road.cc/content/news/52299-sram-red-hydraulic-discs-and-rim-brakes-spy-shots-land ]Hmm interesting.[/url]

Some un-molested pics

http://thedailygrind.robdamanii.com/2012/02/08/sram-red-hydraulic-brakes/

when you're within a couple of feet of each other it could get interesting.

I've ridden in a few chaingangs with our race team, with gaps of no more than a few inches, and this was never an issue. If you can use a dual-pivot brake in this situation, you'll be fine with discs.

I've ridden in a few chaingangs with our race team, with gaps of no more than a few inches, and this was never an issue. If you can use a dual-pivot brake in this situation, you'll be fine with discs.

To be honest i would be more concerned with hot steel discs in a crash situation, chainrings make enough mess as it is if you happen to be in the way.

Colnago have said that their disc braked C59's stopping distance is 52% less than the rim braked model,

Complete BS. Current stopping distances of road bikes are limited by geometry, not the performance of the brakes. Any decent rim brake is powerful enough to send you over the bars if you use it hard enough.

A lot of you are simply [i]guessing[/i] what the differences are (between discs and rim brakes) based on mtb riding etc.

I have two roadies. One runs hydro discs, one runs calipers (Ultegra).

It's not even close. The disc bike is faster (downhill) - more controlled, more consistent. One-finger braking with loads of modulation, wet or dry.

Who cares if people can't see the point in road discs! All that matters is that [b]I[/b] have a choice, and currently that is, unfortunately, limited.

Watching this concept with interest. Less to do with braking performance, more to do with how the wheel can be modified.

All of a sudden carbon clinchers would make sense - currently the ones with ally braking surfaces are heavy and the full carbon ones have iffy stopping (I'm told) and you don't want to score them in the wet...
Potentially you stand to lose a load of weight at the rim, for the addition of a few g at the hub (crossed spokes, disc mount).

Internal hose routing could clean up the aerodynamics a bit (straight down through the fork, exit by the caliper - similar for the back end).

Disc clearance issues can be solved with a bit of ingenuity in lever design. Shimnano Servowave/Avid taperbore thingy is the concept - variable leverage, so the pad can sit a long way from the rotor, move in quickly for the initial part of the lever pull, then have the leverage ratio ramp up once the pad is in contact with the rotor.

Heat dissipation is potentially an issue for brake draggers, but that's the same issue as for MTBs, although the end result of getting it wrong is potentially more dangerous (higher speeds, traffic, etc)

Largely it's about the manufacturers actually deciding they want to do it, and create the appropriate standards. Hopefully they'll have got their sh*t together in 2 years time, when it's my 40th...

[i]Whilst they wont need a braking surface they'll still need to be reinforced or they'd be too weak[/i]

Wheels appear to be on the limit already, while having to contend with rim braking requirements.
[url]

Its slightly frustrating as there is great scope for integrating a caliper into the frame. Heat can disipate through the disc and into a specially designed hub, but also into the frame, which in turn can be deisgned to [i]manage[/i] air flow to cool a caliper, etc.

It would be an interesting challenge to work on disc brake integration into a road frame.

IME, of some concern is the none uniformly distributed, reactionary forces to braking, which act through the frame. Especially on the front, where on my hydraulic equiped commuter, I can epxerience a very unerving reaction in the bike, under certain braking situations. Related to the braking force being on one side of the bike.

Ultimately, as we know, it is do-able and if there has to be [i]something new[/i] delivered to the market to give sales a kick up the back side, then I think we will see it filter into the market.

What I do not like, is the prospect of [i]having to[/i] adopt Di2. Its one thing carrying a multitool with which I can, if necessary, fiddle with a brake or whatever. But stopping because I might get an electrical issue, has potential to be a real PITA, imo.

I'll be looking to firstly see what emerges into the market for disc brakes on road bikes, but also for a cable and hydraulic combination.

Another thing. With the deletion of braking surfaces on the peripheral part of the wheel, you can reduce the mass at the maximum distance from the hub and so reduce inertia.

OP, on the comfort issue, I'd expect there's more to be gained by the removal / redesign of the seatstay 'brake' bridge than any additional material or stiffness needed on the stay to cope with disc forces. But also, a lot more comfort comes from the front triangle than people seem to give credit for, it's not all about the stays.

Has anyone seen the 2013 Roubaix Disc?

http://www.bikerumor.com/2012/07/10/2013-specialized-road-cyclocross-womens-commuter-bikes-roubaix-disc/

I'de give it another year before they put them on at least one Tarmac model.

That spesh looks great - love the clean outline and lack of rim brake surface 🙂

[img] [/img]

Colnago have said that their disc braked C59's stopping distance is 52% less than the rim braked model,

Complete BS. Current stopping distances of road bikes are limited by geometry, not the performance of the brakes. Any decent rim brake is powerful enough to send you over the bars if you use it hard enough.

I suspect it's not complete BS
Being able to squeeze the brake till it throws you over the bars doesn't mean that there isn't a quicker way to stop, you'd struggle to keep a rim brake just at the point of losing adhesion.
We all know what the modulation is like with discs compared to rim brakes.

I have two roadies. One runs hydro discs

Using what brake levers?

love the clean outline and lack of rim brake surface

Back end looks ok. Front looks messy with that cable going down to the calliper. Not a fan of the disc look either. IMO the lack of a braking surface doesnt add much aesthetically.

Being able to squeeze the brake till it throws you over the bars doesn't mean that there isn't a quicker way to stop

So how do you stop quicker without throwing yourself over the bars then?

you'd struggle to keep a rim brake just at the point of losing adhesion.
We all know what the modulation is like with discs compared to rim brakes.

Do we? No problem with modulating the rim brakes on my road bike so that the rear wheel is just skipping along the road.

So how do you stop quicker without throwing yourself over the bars then?

you'd struggle to keep a rim brake just at the point of losing adhesion

Do we? No problem with modulating the rim brakes on my road bike so that the rear wheel is just skipping along the road.

How about the front?

How about the front?

That is with the front 🙄