Discs on the road… The Insider has his say

He works in R&D for a large bike manufacturer and he wants to talk about disc brakes on road bikes (on condition of total anonymity)

by The Insider   January 10, 2012  

Disc rotor

Who could have imagined that we would ever be talking about improving braking on a road bike. Why bother? Last time I checked going slowly wasn’t the aim of the game. But it is coming, without doubt. Disc brakes on the road will be the buzz groupset development of Eurobike 2012 aka 2013 for the market. Fact.

You don’t need to look very deeply into the comments section of articles on the matter to realise this is dividing opinion and it will continue to do so. I am all for discussion but my problem with most of the negative comments is that they seem misguided or misinformed to me.

Allow me to set the record straight. Discs for the road is not just a sly way to make you buy more bikes and bicycle engineers have not run out of scope to improve the performance of framesets. We are just scraping the surface with carbon technology for the bicycle in so many ways. Stagnation on that front will not be reached for a while yet, but I can explain that another time.

Here is my take on discs…

At Eurobike this last year a lot people were surprised that there was no complete hydraulic disc solution on the market. A full 14months on from the UCI lifting the ban on disc brakes in cyclo-cross and still no solution from the big 2.5 component manufacturers [Shimano, SRAM, and Campagnolo], but from an industry view this was no surprise at all. That is because the industry as a whole is nervous of cyclo-cross. If you look to mainland Europe ‘cross is widely considered to be a sport for a) Belgians and b) Professionals. That's not a big market to aim at. Shimano’s amazing cyclo-cross developments with the CX-50/70 are a great example of how tentative the industry is towards 'cross. Two cranksets and a few front derailleurs is hardly massive investment. And that ladies and gentleman is the important word – investment.

Despite its growing popularity ‘cross will never provide the return on investment to justify the development costs. The numbers just don’t add up. If you consider the amount of money that is going to have to be invested to bring discs to the curly handlebar market in a big way, you can rest assured it is not something that will be done lightly. It will not be a fad and it will not be purely for ‘cross

What is most interesting to me is that without realising it the UCI, with its rule change, has sparked a much greater debate in the industry. What was previously an incoherent rumble going on in the background is now a mainstream topic of conversation. Would discs actually provide any advantage to a road bike? Yes. Frame manufacturers are really pushing hard to come up with a frameset in time for the known launch of the complete solution groupset. Discs are coming to the road market, and the cyclo-cross market will benefit as an aside.

With discs come many benefits, but the real advantage will not be from ultimate braking force. It will be consistent and well-modulated braking in all conditions. It will make sense to you when you ride it you just might have to stomach an initial weight penalty and a barely measureable aero disadvantage. Oh and be a little brave to try something new that you don’t like.

I feel sorry for the likes of TRP, Hope and USE that have invested in the converter solution; a good idea but too late - although all three are probably working on fully integrated solutions themselves – TRP are certainly said to be. My guess on which the manufacturer will break cover with a road disc groupset?  Well, it's not a guess I know, but I'm not going to betray any trusts by saying here - it won't be long before you know and anyway it doesn’t take a genius to work it out. With the launch of EPS you are down to 2 from the initial big 2.5.  So it's a groupset manufacturer beginning with 'S' that's in the market for some technical innovation.

For me the most interesting aspect of the industry's decision to embrace disc brakes on road bikes is not the technical aspects of the exercise it's simply how much power the UCI has over genuine technical development,  despite only 0.001% of the world’s cycling community being directly affected by their legislation. If that ban on cyclocross discs had never existed those many millions of cyclists who have never ridden a cyclocross bike let alone raced one would have been riding road bikes with discs years ago."

64 user comments

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For the folk saying this will be too heavy:


6.8 kilos, done years ago.

posted by bazzargh [147 posts]
11th January 2012 - 11:31


Personally, I'm looking forward to disc brakes being available on road bikes.

Advantages for me, leisure, touring and commuting rider:
They work consistently in all weathers.
They don't wear out your rims.

They might be a bit heavier than calipers.

posted by JohnS [198 posts]
11th January 2012 - 12:55


bazzargh wrote:
For the folk saying this will be too heavy:


6.8 kilos, done years ago.

interesting what they say about the fork being a problem area and how their solution was to add two discs. I can see the problem though, you'd probably end up having a stiffer and heavier fork that would put an end to all the 'vertical compliance' stuff. Maybe we'll have to have vertically compliant stems to compensate - Girvin flexstem anyone?

There's clearly some technical issues to resolve with road discs but I reckon a lot of riders objections are aesthetic, which is pretty regressive. The maintenance issue is non-existant, a good disc brake is a doddle to setup and requires loads less maintenance. My hope brakes just need standard workshop tools to service and a bit of tubing when it comes to bleeding time.

joemmo's picture

posted by joemmo [1112 posts]
11th January 2012 - 14:27


JohnS I agree, though think the weight disadvantage (if there is one) is irrelevant.

After the Midlands 'cross championships at Sundorne in December I asked Hope team rider Dave Collins, who took 3rd place, about his disc brakes. Interestingly, he said that riding carbon rims that he felt disc brakes provided even greater benefit in the dry, with predictable braking every time, regardless of the state of the rim.

Simon E's picture

posted by Simon E [2416 posts]
11th January 2012 - 14:53


Sean L wrote:
the aesthetic angle will be hard as brake callipers have pretty much remained unchanged in terms of looks for a century or so.

Can't wait to see what comes forward from manufacturers.

Personally I think the actual rotors have a rather pleasing aesthetic simplicity, but it's true that the calipers often look a bit ugly. But then the MTB design aesthetic is (largely) different from road, perhaps a bit more functional than swoopy if you see what I mean. When the road 'look' is applied it'll be interesting to see what comes out, as you say.

As for actually braking, can only be a good thing as far as I'm concerned- more modulation, less weather dependent, no rim wear, weight neither here nor there (for practical purposes.) What's not to like? Well, apart from cost...

posted by Chuck [498 posts]
11th January 2012 - 15:09


Been riding discs for over a year now on a Kinesis Tripster and i've found them to be great, especially on the rainy commutes. The BB7's definitely seem to be more maintenance than MTB brakes though, and i've noticed the DC19 fork twisting a fair bit under braking - enough that the mudguard rubs the tyre.

posted by ribena [169 posts]
11th January 2012 - 17:12


See the last paragraph of the Garmin-Barracuda story. They're coming!


Simon_MacMichael's picture

posted by Simon_MacMichael [9515 posts]
11th January 2012 - 18:27


Ok I haven't read al of it so sorry if I am repeating some comment.
Being a MTBer (I don't even own a "proper road bike") I have a lot to say about disks. To start with:
putting a wheel with a disk in is as easy if actually not easier than a rimmed brake wheel.
Weight is actually going to be the same if not lighter. Brake cables are made of good old heavy iron/steel, so having fluid inside is going to save you quite a lot. I terms of calliper/master cylinders, back in the days, the formula B4 was already lighter than a set of XTR V-brakes. As for the weight of the wheel, get the difference of the 717 disc and the 717 non disc and compare it to the difference of disk and non disk hope XC hubs.
Maintenance basically there is no such things as maintenance on a disk brake system. It's fit and forget on a mtb so I can't see road riding been nastier for brakes. Changing the pads is actually a lot easier than setting up some foucking rim brakes. And bleeding is actually easier and faster than changing a cable or even greasing it.
As for the fork managing it, carbon forks for MTB already exits, and they seems to cope just fine. Actually I can see the benefit of having the equivalent of the QR15 front and the 142 rear standard for road bike specially in terms of rigidity.

would you ride/race a road bike with a quill stem? Gear with no indexations? Both thec come for the mud side, and back in the days were considered to be the work of evil Wink.

P.S. I know for advance this post is going to be full of mistakes, I'll correct them later tonight once I have access to an english spellchecker Wink

posted by juan [11 posts]
11th January 2012 - 19:24


Well to be fair, magura disk brakes can only stop a road bike Wink. They are not very well regarded in the mtb community.

However and this where i think you're wrong Wink I quite can see hope being amongst the very first ones to do a braking system for road bikes, something that will accommodate mtb shifters.

posted by juan [11 posts]
11th January 2012 - 19:29


I had a custom ti CX frame built for discs built 6 years ago because they simply didn't exist at that time. The arguments about increased maintenance and poor reliability are spurious IME - BB7s are very easy to set-up and maintain and far less fiddly than many road brakes - if you can turn and Allen key you can install and service them! Whilst they are great for general trail riding, I still run cantis on my CX race bikes because the main issue for me is grip, not stopping.
On the road I see bigger benefits for discs - particularly using carbon wheels in the wet and better modulation and control on high speed descents. However, the possible downside is that riders will take bigger risks and we may see more incidence of high speed crashes on descents because riders will compensate for better brakes by riding faster / braking later - I'm afraid incidents like Casartelli or Weylandt may be more common.

Make mine an Italian with Campagnolo on the side

posted by monty dog [433 posts]
11th January 2012 - 20:07


A disc brake wheel is a lot faster to change in my opinion, after spending a month assembling demo MTBs and road bikes. All you do is undo the QR (and unscrew it so you can get it over the idiot-tabs) pull it down and out. Reverse the process for a fresh wheel with a fully inflated tyre. Doneburgers.

It negates the need to undo the calipers (using that lever everyone loves to forget to redo after the wheel-change, which you only remember when you need pull the lever when going way too hot into the next corner), deflate wider touring tyres, check the alignment of brake pads (ever) or worry about your carbon rims, especially when you are a Clydesdale rider like myself.

posted by Ciclismo [21 posts]
11th January 2012 - 20:56


Bring it on I say! No more switching pads between my alu crit wheelset and full carbon road race wheelset. Cuts down on repair time as well if you're caught with a tire mechanical on the race course. Just loosen skewer, pull and go. Allows for the use of wider tires when course conditions dictate as such without penalty for running current itty-bitty side-pull calipers. I'm lucky if I can fit a 24c tire in my current caliper without loosening the tension bolt first.

posted by advcyclist [2 posts]
11th January 2012 - 21:34


Don't think rotors will be bigger as mtb generally have to stop higher weights with a sketchier surface (with discs often in mud) Discs contact patch could be wider if this was an issue - but think the key is modulation not emergency. The wheels on a road bike will lock up a plenty with 120mm rotors. Expect hubs to beef up slighter and rims to become lighter and more triangular ....

richdirector's picture

posted by richdirector [59 posts]
11th January 2012 - 21:45


Use discs on MTB and CX commuter and they are great. Wheel weight is currently an issue so road bike is calliper braked. When I jump back on the road bike I am always a bit horrified how crap callipers are compared to discs, but I love the zing of the lighter wheels and soon adjust to longer stopping distances.

Discs are BRILLIANT for panic stops on the road in commuter land. When it's wet I always take the disc CX bike, if only cause in the wet drivers seem to drive 5x worse (worse visibility I guess).

However there is a point no one has mentioned: The reason track racing is actually pretty safe is because NO ONE has brakes. In a road pack everyone's brakes are about the same so again everyone is braking poorly at relatively the same rate. If you put a couple of people in the peloton with discs and most with callipers the extreme difference in stopping ability is going to mean carnage for a year or two until everyone catches up. I suspect that's when the teams and UCI get to work Smile

Once you have ridden a disc equipped bike down an unknown mountain pass in the rain you get it. They're not yet for road racing and ultimate go-fast club, but they will be more useful for most riders. No rim wear... very light carbon rims... hydraulic action... mmmm....

So, innovation, yes please. Have you ridden a race bike from the 70s or 80s recently? I have a lovely steel road bike, but it's a 00s Salsa with a carbon fork, knocks the spots off anything else I rode in the 80s including Gios', Team Raleighs etc etc. I suspect I will be saying the same about road brakes in 10 years...

alotronic's picture

posted by alotronic [417 posts]
11th January 2012 - 23:00


monty dog wrote:
the possible downside is that riders will take bigger risks and we may see more incidence of high speed crashes on descents because riders will compensate for better brakes by riding faster / braking later - I'm afraid incidents like Casartelli or Weylandt may be more common.

I don't think so Monty.

Did more crashes occur when they started wearing helmets (as opposed to the hairnet ones)? Have STIs prompted more wobbles than downtube or bar-end shifters? Did more people crash cars when synchromesh replaced crunch gearboxes and double-declutching?

The bolder riders will recalibrate their braking just as finely as they do now. They also stand to benefit more than us mortals from the absence of rim heat build-up on long descents as they'd be going considerably faster already and the braking will be more predictable than with rim brakes.

No-one is arguing that a climber on a 6kg road bike on skinnies needs the stopping power of a 14kg DH race rig with fat tyres so the braking power will be appropriate for the machine (which I hope means small rotors and tiddly calipers. TBC the adoption, or lack of it, by pro race teams is merely about marketing. I still see the biggest beneficiaries being those of us who ride all year round.

Simon E's picture

posted by Simon E [2416 posts]
11th January 2012 - 23:45


The first daredevil who pulls a minute out on a long (maybe wet) descent on the TDF - and the jig is up - they'll all be in then ...


posted by GeeTee [5 posts]
12th January 2012 - 0:29


For those of us whose best option to reduce our bike weight by 5 kg is to stop putting cream in our coffee (rather than spending $2000 to reduce component weight by 500 gr) adding disk brakes would add a great deal of safety while adding only the miniscule speed penalty.


roberdj's picture

posted by roberdj [15 posts]
12th January 2012 - 0:51


The Canyon article is quite interesting and exposes some of the potential pitfalls (high fork stress, asymetric braking force affecting handling, heat transfer damaging the carbon structure). Also interesting they considered a cross FOUR wheel necessary. From an engineering point of view its pretty clear that the design of the fork needs to be considered extremely carefully. I wonder if the component supplier "S" is expecting this design to be handled by the frame/fork manufacturer. It is likely that many smaller companies don't have anything like Canyons engineering expertise. Also, higher braking efficiency will come with a downside - consider how fragile 700c tires are - the tiny contact patch means locking up has a high likelyhood of blowout.
American liability lawyers are probably rubbing their hands with glee.

posted by imaca [59 posts]
12th January 2012 - 2:59


alexpalacefan wrote:
Worries about maintenance? I hadn't seen that angle. Still, it will be a boon for MTB trained mechanics, who have been working on these things for years.


Excellent point. is there a point here also with Magura signing up with the new Garmin team? Shape of new Cervelo things to come?


posted by seanieh66 [197 posts]
12th January 2012 - 4:23


Once again lot of "suposition". Asymetric braking force affecting handling... Of course, MTB (and motorbikes) all goes on the side when you brake indeed.
Heat transfer damaging the carbon, once again there is no such thing as carbon brake disks. And carbon mtb are obviously known to be damaged by heat.
Plus and this is where you all get it wrong a bisk brake won't add power but more power and progresivity.

P.S. Once again I haven't got the english spell checker. I'll correct this post tonight.

posted by juan [11 posts]
12th January 2012 - 9:43


I cant believe discs have been so long coming. For all us regulars the weight penalty is insignificant and the braking benefit is huge. Whats more I dont want to have to replace my new Mavics too soon.
And lets face it - rim brakes were last seen on horse drawn carts.


posted by alg [158 posts]
12th January 2012 - 11:00


ppf What a bunch of wally's a lot of you are!!! What type of brakes are fitted to motrcycles and cars???? EXACTLY!!
Once they are fitted as std on some tourers,audax,winter,commuter road bikes,the development of lighter,sleek looking assemblies will naturally follow! Being a car driver and motorcyclist having ridden drum brake versions (some cars were very scary,with slow you down eventually type brakes)then progressd to disc versions, I would never consider goin back. Disc brakes have a lot of advantages on cycles,I ride mtbs,and ride a disc brake mtb on the road with slicks. I personally cant wait for the fitment on a road bike. All the worries about,disc sizes,weights,looks,etc will evolve in a short time,TRUST THE TECHNOLOGY. Test it before you pass a comment!


posted by peasantpigfarmer [47 posts]
12th January 2012 - 13:38


ppf ref.JUAN Carbon discs have been used in motor sport for many years now.probably don't think it will be required on cycles though.


posted by peasantpigfarmer [47 posts]
12th January 2012 - 13:45


Hi there, We've been using disc brakes for years, thats what wheel rims are! But the use of disc at the hub part of the set up is more recent 1960's.So in fact nothing is new, only the improved materials & engineering systems have made them more practical. I'm currently in the process of having a new trike built with rear disc brakes. The entire braking system stays on the frame when the wheels are removed.Less messy than hub brakes on the rear. The weight of the new components make it quite practical, but I don't want the same arrangement on the front, as that would require stronger forks. TTFN MM

mersey mouth

posted by mersey mouth [7 posts]
12th January 2012 - 14:42


roberdj wrote:
For those of us whose best option to reduce our bike weight by 5 kg is to stop putting cream in our coffee (rather than spending $2000 to reduce component weight by 500 gr) adding disk brakes would add a great deal of safety while adding only the miniscule speed penalty.

Nail on head.

Since I finally quit smoking (and ballooned), the beautiful and expensive Campag rim brakes on my Ti Audax bike haven't brought me to a locked-up stop. In this time, the cheapo discs on my (marginally heavier) Boardman hybrid haven't failed to stop me in significantly less distance, and have done so with much less worry about breaking myself or the bike.

My eyes prefer Celeste, my bum prefers titanium.

Jack Osbourne snr's picture

posted by Jack Osbourne snr [384 posts]
12th January 2012 - 22:07


I came from MTBs onto road bikes, and have never felt anything like as confident with rim brakes as with my Hope disks.
Greater stopping power, more predictable in the wet or mud, less adjustment needed with wear, less wear on your rim, easy to change wheels (who said it would be slower? disk wheels are easier to swap in my book), no cable stretch, I could go on. Disks win for me, any day.
And the weight penalty? Yes, a disk wheel will be slightly heavier, but can be lighter at the rim, heavier in the middle. Shouldn't bother anyone unless they only ever ride up hill, and then catch the train back down!

posted by kace19 [23 posts]
13th January 2012 - 15:25


More progressive, consistent & predictable braking to be welcomed (on my commuter/utility bike for instance). If my weekend road bike can remove it's braking surface from the rim then manufacturers can also make wheels with rims both stronger and with much less rotating mass than currently possible (leaving just my fat arse to drag up the hills).
BUT are we talking about existing disc hubs (135mm) or a whole new line of 130mm "Road Disc Hubs"?
I usually groan cynically when I see new advances in technology but this one makes a lot of sense. Lets see what SRAM's 2012 groupsets bring. I need a Do-Everything-bike this year...

posted by herohirst [68 posts]
24th January 2012 - 19:42


The biggest mechanical problems are going to be assymetric loading on forks (but that's not insoluble, esp with carbon - I have cut up a lot of carbon forks over the years that have had decidedly assymetric blade flex rates) and on the rear, the whole 130 / 135 mm OLN conumdrum.

The biggest difficulty with rear end dimensions, as I see it, will come in the pro / serious amateur peloton - it's bad enough now with 10 and 11s systems to cater for if we are running neutral service (worse than when we had the 9 / 10s divide, roll on DA 11s), but if we have two different rear end dimensions, then we might have a real headache on our hands.

Back in the day, when we made the shift from 120 to 126mm rear triangles it wasn't too bad as steel frames could be "persuaded" with the QR or sprung, and in any case adoption of the new 126 width was very quick - I only recall it taking about two seasons to pass right the way through from pro to 3rd cat. amateur ... and 126 - 130 was also still in the steel era and to a great extent the same thing applied. Gear systems were less picky, there was more slop in the system and we managed it all OK.

Now 130 / 135 is going to give us a headache with rear end spacings beacuse you can't play quite so fast and loose with carbon or alloy frame spacings ... shifting an alloy rear triangle 5mm is a job for strong fore-arms and a carbon frame - well, it's just a no-no.

Gear systems are also a bit more picky about alignment these days and forcing rear triangles can cause all sorts of function problems.

Add to that the problem of rotor-to-seatstay and rotor-to-chainstay clearance when you put a disc wheel (with a 130 hub) into some road frames and you're going to see a lot of very harassed-looking mechanics trying to do a wheel changes in the heat of competition.

Last, if we keep 130 rear ends and move the rotor inboard a tad, then the hub flange spacing starts to look a bit iffy - it's bad enough on some rear wheels now - especially when you start to look at the torque-transfer requirements of disc brakes.

I'd stress that none of the above is insoluble ... but it'll take a very brave innovator to start the ball rolling in the race market.

What would make more sense would be for that "manufacturer beginning with S & looking for innovation" to apply development to the drop-bar commuter market, a far larger and much less conservative / image driven market than road racing / cross will ever be, thrash out the headaches there, use the numbers to drive volume and force a ground-up acceptance. That's what I'd do ... but then I don't have Goldman Sachs behind me Smile

This week I have mostly been riding a Mondiale in Deda V107 with Campagnolo Super Record 11 ...

posted by velotech_cycling [78 posts]
28th January 2012 - 3:49


I just picked up a new bike and I purposely stayed away from disc not because they aren't a higher quality. But because the standard brakes are much easier to work on and find parts for. I got this bike here http://www.2wheelbikes.com/rs888-racing-bike.html

posted by raysauce [6 posts]
15th February 2012 - 21:49


I like the name "idiot tabs" - I cycled home from work one and wondered what the rattling sound was. I then hit a bump and promptly broke three ribs. Still got back on and rode home though!

If cycling is indeed a sport of self-abuse why aren't more cyclists sectioned under the mental health act?

posted by hairyairey [295 posts]
1st June 2013 - 0:18