Author Topic: Disc brakes in the pro peloton  (Read 13433 times)

Re: Disc brakes in the pro peloton
« Reply #50 on: 30 March, 2018, 09:11:10 am »
Zinn says that discs have a weight penalty and an aero penalty. However:
* many pro bikes are brought up to the UCI limit by the mechanics adding weight (which I think explains why so many of them ride the "aero road" rather than the super lightweight bikes from the relevant manufacturer).

Every time someone weighs the bikes, they find this not to be true. Some of them are around 8 kg and even the climber’s machines are rarely at the legal limit. They ride aero bikes because they’re marginally faster and the sponsors want them to, and because weight doesn’t make much difference even at this level of competition.

* both Specialized and Giant claim that their latest aero disc bike is as aero as the non disc version.

So who should we believe: a technophile with no visible vested interest whose job it is to be expert in these matters or a company whose success depends on the public perception that disc brakes belong everywhere?

Don’t get me wrong: I don’t think the tiny burden in weight and drag of disc brakes makes a button of difference in 99 out of a 100 races. The marginal-gains palaver has got people thinking these things matter a great deal more than they do.

But disc brakes are being pushed despite fractionally harming racing performance. This situation is novel, because previous new tech in the avalanche of change over the last two decades has infinitesimally improved performance (while it’s worked, at least), allowing us to suspend disbelief about why it was introduced. No longer!

On weight, it's not hard to build a bike under the UCI limit if money isn't an issue. I understand they run alloy bars and other stuff to provide resilience over lightness, but if they are 8kg, it just shows how much they care about bike weight.

When it comes to aero, I believe the people with wind tunnels. ;) If you can point me at experiments on the latest Propel disc or Venge Vias disc, I'd love to read them. As you said, aero trumps weight, and if these bikes are as aero, then the only downside is the wheel change situation.

zigzag

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Re: Disc brakes in the pro peloton
« Reply #51 on: 30 March, 2018, 10:08:14 am »
the speed of wheel changing will be a non issue as the tubeless tyre technology matures (it's getting there) and pro peloton adopts it.

Samuel D

Re: Disc brakes in the pro peloton
« Reply #52 on: 30 March, 2018, 10:14:35 am »
With disc brakes, it’s still non-trivial to hit 6.8 kg in a fully kitted-out racing bicycle. You need to make some tough choices to get there.

Thankfully we’ve moved away from the weight obsession anyway, such that even pros care less about this than they used to. The new obsession is drag reduction, something that is complex enough that almost any claim can be supported by cherry-picking the evidence (modelling assumptions, wind-tunnel set-up, yaw angle, time versus speed versus power versus drag force saved over different distances, times, etc., etc. You can’t even get experts to agree on these things and yet Specialized – to pick the worst offender – is happy to boil down everything to a single figure of merit that fits in a clickbait title).

This new environment is a marketing windfall, and the American companies that excel at this haven’t been shy to hit us with unlikely claims.

I can’t point you to drag tests beyond the advertisements for the Propel Disc or Venge ViAS Disc. But from what I’ve read from reputable or knowledgeable sources – excluding the manufacturers’ propaganda – disc brakes have slightly more drag.

Kittel’s Venge ViAS Disc from last year weighed 7.95 kg.

mattc

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Re: Disc brakes in the pro peloton
« Reply #53 on: 30 March, 2018, 10:21:15 am »
Matt, let's go back to where you started this.

Face it, cycling is a sport that is fundamentally about using technology to enhance man's capabilities.  If you don't like that, it isn't the sport for you.
My dear chap, that is nonsense.
Ok, let us go back to the start:
This is the crux of it - lots of us don't watch (or "do") cycle sport for the technology. It is still the sport for us. I don't know why you presume to tell us what we think.


(That doesnt mean a complete lack of interest in the tech - it's just not why we watch.)
Has never ridden RAAM
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No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

Re: Disc brakes in the pro peloton
« Reply #54 on: 30 March, 2018, 10:34:52 am »
You bring up Formula One. That sport is a farce lurching from one financial crisis to the next precisely because it allows too much freedom to buy success. Special effort or talent – whether creativity of concept, natural driving talent, persistence, or other admirable sporting merit – isn’t enough there. You need to blow £20 million on engine-development drudge-work or you’ll be an also-ran. Consequently most of the drivers are chosen because they’re rich or famous rather than good at their nominal job.

There aren’t many sports looking at Formula One and thinking they’d like a bit of that. It’s no longer a sport in the traditional sense. To the limited extent that driving can still be considered a sport, it’s undermined by the fact that the cars are more significant to the outcome than the drivers. If it’s a sport at all it’s a game of business acumen: how can you hoodwink the rule-makers, scare up another £10 million in funding from your parent group, manage an agile organisation, write the smartest contracts, optimise your marketing spend, etc. Who cares? Fewer and fewer people, judging by its decades-long decline.

I understand technology and admire it more than most people. However, cycling is firstly an athletic endeavour, and road racing should pit men and women against each other in a competition of strength and wit. Otherwise it betrays its past and becomes another beautiful thing spoiled by American-style consumerism.

Since technology in cycling or any sport will always be limited by the rules, the line in the sand will always be somewhat arbitrary. I’m arguing for a line that reduces costs and therefore barriers to participation and helps develop cycling as a force for good in the world.

On the latter point, it’s depressing how many problems these fragile bicycles have today. Dropping out of a race because your Di2 derailleur glitches out has become downright common.

And disc brakes are even weirder because they positively harm performance even when they work correctly. It’s purely technology push with no benefit for anyone except the bike-manufacturing sponsors, which is why I’d like to see them replaced with supermarkets and sanitary-fittings specialists. At the moment the tail is wagging the dog and the sport is too broke and incompetently run to protest.
Eloquent and informed. Thank you.
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mattc

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Re: Disc brakes in the pro peloton
« Reply #55 on: 30 March, 2018, 10:40:22 am »
Regarding wheel changes in the peloton, neutral service has always had to make assumptions and/or compromises on rim width and sprockets. Introducing disc brakes just adds another factor to assume and compromise, it's not the origin of the issue.

If there is ANY chance of neutral service not having the right spare for you, then you've just doubled that chance by adding this extra factor.

(This does happen - first google hit was a "ride-along" article where rider on 10-speed had to make do with an 11sp until a team bike was available. In the event of a crash the chances go up enormously.)
Has never ridden RAAM
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No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

zigzag

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Re: Disc brakes in the pro peloton
« Reply #56 on: 30 March, 2018, 11:19:01 am »
as to the drag of bike frames, there can be significant differences and as long as the tests are done in a controlled environment by a third party i see no reason not to believe the results. manufacturers, as we all know, will spin the test results their way, so they are not the source of information to be assumed as true/real.

Re: Disc brakes in the pro peloton
« Reply #57 on: 30 March, 2018, 01:12:36 pm »









Don’t get me wrong: I don’t think the tiny burden in weight and drag of disc brakes makes a button of difference in 99 out of a 100 races. The marginal-gains palaver has got people thinking these things matter a great deal more than they do.

But disc brakes are being pushed despite fractionally harming racing performance. This situation is novel, because previous new tech in the avalanche of change over the last two decades has infinitesimally improved performance (while it’s worked, at least), allowing us to suspend disbelief about why it was introduced. No longer!

[Disc brakes] obviously didn't disadvantage him either.

You cannot see their weight and drag on television. Nor can you assess puncture risk with a sample size of one.

He made his choice and he won; no disadvantage proved. If he had come second or if he had blown up and been caught by the bunch (as should have happened and was predicted to happen by people more knowledgeable than me or, I would guess, you) then there might have been a case. If he had punctured and taken 15 minutes to get going again, ditto. It didn't happen, he won with a very clever bit of sprinting.
It was a wet day and he was away with Rubio from the start. He is known as not a good descender so it was no surprise to see Rubio pull out 50-100m on the descents. Did the discs help him stay in contact? There again case not really proven, one way or the other. Too soon to draw conclusions.

If you want to know about racing with a real disadvantage from your contracted machine, read Dr. Ruffier's acounts of his racing days under contract to ride the Alcathène (1890's IIRC, I will go and hunt out my copy to check over the w-e). It's from his 50 Years of Cycletouring articles; you're in Paris, you should be able to track it down. It's also in the french of a 19th century doctor so anglophiles may find it a bit hard going.
Edit I think that should be Alcatène; alkathene is plastic pipe!

Karla

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Re: Disc brakes in the pro peloton
« Reply #58 on: 30 March, 2018, 04:00:14 pm »
Matt, let's go back to where you started this.

Face it, cycling is a sport that is fundamentally about using technology to enhance man's capabilities.  If you don't like that, it isn't the sport for you.
My dear chap, that is nonsense.
Ok, let us go back to the start:
This is the crux of it - lots of us don't watch (or "do") cycle sport for the technology. It is still the sport for us. I don't know why you presume to tell us what we think.

Matt, stop being idiotic.  Cycling is a sport that is fundamentally about using technology to enhance man's capabilities.  The bicycle is a piece of technology that is used to allow you to go further and faster than you could do otherwise.  Stop rubbing your face in the egg, stop casting around straw men and just accept this simple fact.

mattc

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Re: Disc brakes in the pro peloton
« Reply #59 on: 30 March, 2018, 06:54:30 pm »
It's about who can ride a bike the fastest.

Your description isn't completely at odds with that, but  it puts a very different emphasis on certain elements.

I would say that most televised cycle sport is more about the riders than the tech - whereas HPV racing is pretty much the opposite. Each has its followers (for good reasons), but I think it's pretty clear which is more popular, and which will continue to be the more popular for as long you live.


Now, get back to the timetrialling forum and your discussions of overshoe drag  :-*
Has never ridden RAAM
---------
No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

Re: Disc brakes in the pro peloton
« Reply #60 on: 30 March, 2018, 07:20:02 pm »
A pro cyclists view on disc brakes -

https://www.youtube.com/watch?v=Jfso8wP83bU

Karla

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Re: Disc brakes in the pro peloton
« Reply #61 on: 30 March, 2018, 07:40:12 pm »
It's about who can ride a bike the fastest.

Your description isn't completely at odds with that, but  it puts a very different emphasis on certain elements.

I would say that most televised cycle sport is more about the riders than the tech - whereas HPV racing is pretty much the opposite. Each has its followers (for good reasons), but I think it's pretty clear which is more popular, and which will continue to be the more popular for as long you live.


Now, get back to the timetrialling forum and your discussions of overshoe drag  :-*

Nice climbdown there. 

Re: Disc brakes in the pro peloton
« Reply #62 on: 30 March, 2018, 09:07:13 pm »
It's about who can ride a bike the fastest.

Your description isn't completely at odds with that, but  it puts a very different emphasis on certain elements.

I would say that most televised cycle sport is more about the riders than the tech - whereas HPV racing is pretty much the opposite. Each has its followers (for good reasons), but I think it's pretty clear which is more popular, and which will continue to be the more popular for as long you live.


Now, get back to the timetrialling forum and your discussions of overshoe drag  :-*

Nice climbdown there.

The continental idea of cycle racing has always been to concentrate on the personalities and the human story rather than the technical side. The anglo-saxon view has usually concentrated on the technical side. The reasons for this are probably in the popular following of cycle-racing by sedentary or non-cyclists, either watching the tele with a few beers sunday afternoon or by reading in the papers on the continent (and the role of the Tour caravan, which has little to do with the bike and a lot with the personalities). In my young day (even up to 25 years ago) there wasn't much popular following of cycle-racing in UK by non-cyclists and in the absence of the personalities, the technical side was more interesting for practising cyclists. The whole difference was better explained by JB Wadley in The Guiness Guide to Bicycling published in the 1977 (which was an english translation of a french book).

mattc

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Re: Disc brakes in the pro peloton
« Reply #63 on: 30 March, 2018, 10:48:49 pm »
It's about who can ride a bike the fastest.

Your description isn't completely at odds with that, but  it puts a very different emphasis on certain elements.

I would say that most televised cycle sport is more about the riders than the tech - whereas HPV racing is pretty much the opposite. Each has its followers (for good reasons), but I think it's pretty clear which is more popular, and which will continue to be the more popular for as long you live.


Now, get back to the timetrialling forum and your discussions of overshoe drag  :-*

Nice climbdown there.
Er .... thanks. I think.
Has never ridden RAAM
---------
No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

Re: Disc brakes in the pro peloton
« Reply #64 on: 31 March, 2018, 07:57:38 am »
Regarding wheel changes in the peloton, neutral service has always had to make assumptions and/or compromises on rim width and sprockets. Introducing disc brakes just adds another factor to assume and compromise, it's not the origin of the issue.

Surely all the neutral service has to do is carry wheels with discs and brake-compatible rims?

We're into standards and permutations again, QR or 12 mm or 15 mm or 20mm thru axle. As others have said it's nowt new, witness Froome on the neutral service bike with cleats and pedals that didn't match.

cygnet

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Re: Disc brakes in the pro peloton
« Reply #65 on: 31 March, 2018, 07:41:58 pm »
Also at all levels in U.K.


Does anyone know about overseas? The FFCT/ASO had issues when they were last introduced I know, (e.g. being disallowed in the Etape etc)

Cr***p The FFCT is nothing to do with cycle sport and certainly not L'Etape or ASO. As far as I know the FFCT has no policy on bikes other than lights, bells and reflectors - it even allows e-bikes in randonnées. It also loves vtts so has a high opinion on discs (and encourages vtts in road as well as off-road use as far as I can understand from local instructors - you can use a vtt for the road part of the Initiateur qualification - but not a road bike off-road!)
OK FFC. My mistake.
http://www.sportive.com/cycling/522490/ffc-ban-casts-doubt-over-use-of-disc-brakes-in-la-marmotte-and-letape-du-tour

Is this still the case or have changed their minds?
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Re: Disc brakes in the pro peloton
« Reply #66 on: 01 April, 2018, 02:53:36 pm »
Also at all levels in U.K.


Does anyone know about overseas? The FFCT/ASO had issues when they were last introduced I know, (e.g. being disallowed in the Etape etc)

Cr***p The FFCT is nothing to do with cycle sport and certainly not L'Etape or ASO. As far as I know the FFCT has no policy on bikes other than lights, bells and reflectors - it even allows e-bikes in randonnées. It also loves vtts so has a high opinion on discs (and encourages vtts in road as well as off-road use as far as I can understand from local instructors - you can use a vtt for the road part of the Initiateur qualification - but not a road bike off-road!)
OK FFC. My mistake.
http://www.sportive.com/cycling/522490/ffc-ban-casts-doubt-over-use-of-disc-brakes-in-la-marmotte-and-letape-du-tour

Is this still the case or have changed their minds?

https://www.ffc.fr/actualite/federation-francaise-de-cyclisme-prend-acte-de-position-de-luci-lutilisation-freins-a-disques-epreuves-de-masse-rappelle-interdiction-competitions/   is what Google has shown on the subject and this is copyright 2018. So it would appear that even though the UCI authorises discs except in national and international races the FFC take note but still ban them in all competition on french soil. Remains to be seen if sportives are considered races or manifestations de masse  (in UFOLEP terms they count as cycletouring!). I would like to see something definitive with a 2018 date, rather than decisions from 2016. Anyone got anything better?

Edit: found this as well 
http://www.granfondoguide.com/Contents/Index/1448/the-uci-gives-the-go-ahead-for-disc-brakes-to-be-used-in-mass-cycling-events

It seems that the FFC are being typically french - we're banning it but you can still do it, only don't tell us!

Edit 2. This also  http://www.sportive.com/cycling/533935/letape-marmotte-flanders-are-disc-brakes-allowed-on-sportives-now

It looks like you have to check with the various organisers! The article is from last year.

Re: Disc brakes in the pro peloton
« Reply #67 on: 02 April, 2018, 08:29:23 am »
The UCI have said that national federations can choose whether to allow disc brakes or not so expect some
confusion for a while yet.
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Vince

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Re: Disc brakes in the pro peloton
« Reply #68 on: 02 April, 2018, 09:43:18 am »
HOLD ON, HOLD ON, HOLD ON!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I only asked a simple question; I didn't mean to start an intertribal war!!

FWIW I got to see this stage again this evening, right up to the thrilling finish in which the two man breakaway held off the bunch right up to the end (in part due to a complete disorganisation of the sprinters' teams). The winner was the man with the discs!! but I cannot say that they really played any vital part in his victory which was due to a superior finishing skill. They obviously didn't disadvantage him either. There would appear to still be a real place for skill and tactics (and a bit of luck) in pro road racing.

So will the Luddites go into the room on the left to smash up carbon frames and spinning jennies with sledge hammers, the modernists go into the room on the right to hunt for the latest marginal gains (and undoubtedly scratch theircricket balls with sandpaper if that takes their fancy) and the lovers of tradition take their Draisiens down to the local cinder track (avoiding the horsemuck in the streets on the way).

Like it or not cycle racing is and always has been a mechanical sport; my personal take is that in trying to align with the IOC and make out that racing is purely about athleticism and not mechanics the UCI is making a big mistake - but I could be wrong since that appears to be where the money and political clout is.

End of Rant :)

POTD
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Re: Disc brakes in the pro peloton
« Reply #69 on: 22 May, 2018, 09:42:41 pm »
Regarding wheel changes in the peloton, neutral service has always had to make assumptions and/or compromises on rim width and sprockets. Introducing disc brakes just adds another factor to assume and compromise, it's not the origin of the issue.

Surely all the neutral service has to do is carry wheels with discs and brake-compatible rims?

We're into standards and permutations again, QR or 12 mm or 15 mm or 20mm thru axle. As others have said it's nowt new, witness Froome on the neutral service bike with cleats and pedals that didn't match.

Is there a standard rotor size yet?

My big problem with discs is the lack of travel on the brake pads which means brake rubbing. With a caliper brake, i could just twist the caliper to line it all up again, not so with discs!

LEE

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Re: Disc brakes in the pro peloton
« Reply #70 on: 22 May, 2018, 09:55:39 pm »
My big problem with discs is the lack of travel on the brake pads which means brake rubbing. With a caliper brake, i could just twist the caliper to line it all up again, not so with discs!

On my mechanical (cable) BB7s that's an issue but not on my full hydraulics.
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Re: Disc brakes in the pro peloton
« Reply #71 on: 22 May, 2018, 09:55:39 pm »
It's really easy. Loosen the caliper bolts. Apply brakes. Tighten bolts.

The only issue I've had is with cheapest cable disc brakes where I had to shim them to get them centred.

Re: Disc brakes in the pro peloton
« Reply #72 on: 22 May, 2018, 10:13:04 pm »
I've heard of problems with nervous novices grabbing brakes in the peloton.  I seem to recall that Campag designed brakes for road-racing specifically not to grab too hard.

Re: Disc brakes in the pro peloton
« Reply #73 on: 22 May, 2018, 10:32:35 pm »
Yes, the Delta. Didn't realise it was designed to be shit.

I thought it was just..err ...shit.

LittleWheelsandBig

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Re: Disc brakes in the pro peloton
« Reply #74 on: 22 May, 2018, 10:38:06 pm »
Yes, the Delta. Didn't realise it was designed to be shit.

I thought it was just..err ...shit.

No, their normal single pivot design.

Did you ever use a set of properly set up Deltas? With a couple of washers to get the linkages in the right position with narrow rims, they worked nicely. Those who ran them with the linkages protruding at rest and tried to wear their brake pads paper-thin always complained of a lack of power.
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