Tubs vs clinchers: Clinchers are faster..

[ElChingon]

If rolling resistance is so important, shouldn't we all ditch our racing 23s in favour of 25s

Only those that drink the cool-aide are switching.

 

[BroDeal]

If rolling resistance is so important, shouldn't we all ditch our racing 23s in favour of 25s

Already have. The 25s are superior in every way.

 

[BroDeal]

When Guesdon won Roubaix in '97 on Michelin Pro2 clinchers we were saying the same things for a minute. I will eat my words if all of a sudden clinchers become the preferred choice for TT's, but I'm not holding my breath. History has a weird habit of repeating itself.

It is a different environment now. A bunch of teams pride themselves on looking for every marginal gain.

 

[Alex Simmons/RST]

No way in the world you can attribute that time split to a tire because of what an indoor lab test that doesn't recreate real conditions is telling you. A million other factors are defining those times.

I respect you Alex, you've put in a lot of time on and off the bike to promote the sport and you are to be commended. Several of the last 22 years I've worked this industry in marketing and consulting of wheel specific goods, and have sat across the table with companies that have laundry lists of professional race wins, sponsoring the who's who of racers telling me flat out "we have to lie if this is going to sell"! Keep that in mind when you empty your wallet for the sake of chasing the all mighty Unicorn. In the last few years I have since dissociated myself from the kind of work I used to do due to ethical reasons and ran back quickly to what I love to do most, is build wheels that make sense. I'm completely aware that I'm the Atheist in the room of a bunch of religious fanatics.

Who says my tests were not conducted under real conditions, or that the data as obtained from Al Morrison's roller tests don't translate to the real world?

Andy Coggan has a really neat chart showing real world (i.e. road) Crr vs Al's roller test numbers for a range of tyres with a range of Crr values. It's a really nice linear correlation:

http://www.trainingandracingwithapowermeter.com/2010/12/crr-roller-vs-field-test-results-part.html

and part I of that item:
http://www.trainingandracingwithapowermeter.com/2010/06/crr-roller-vs-field-test-results.html

You will see that testing on the rollers to assess relative Crr translates well to relative Crr on the road.


Now if we consider the two tyres on Andy's chart in that latter linked item with the least difference between them in terms of Crr, i.e. the
- Veloflex Record clinchers and the
- Bontranger RXL Aerowing clinchers

The impact on speed due to Crr differences is 0.2 seconds per km. Knowing the tyre my competitor did use was considerably worse (over 1 sec/km slower) than mine, I can assure you I know very well that it had a sizeable impact on the result that day.

I have no vested interested in what tyre is the best other than making a sensible choice for best performance according to the criteria I have. I don't give a toss whether it's 19mm or 25mmm, tubular or clincher.

That choice will be an assessment of all relevant performance characteristics, especially aerodynamics, Crr, and suitability for the type of event, amongst others.

I think it was Kraig Willett who said: "faster is faster, right?"

What I am saying is that people should consider the actual data and not be so dogmatic as to believe whether tubs or clinchers or whatever is better.


As as for testing in the real world, you might be interested to know that only last week, for the first time ever, the technology to provide real time Crr data was being calculated and updated on a laptop computer based on data transmitted from a rider riding on a track. Here is the lap by lap data grab from the initial test run:

https://docs.google.com/file/d/0B6trLQ0bIleqbzJYamg5azY5Tjg/edit?pli=1

Don't get hung up on the precise numbers or notes in the tables, it was a test of technology to show what we can deliver in real time, rather than a tightly controlled test for Crr.

The technology's primary use is the delivery of real time aerodynamics (CdA) data (wind speed, yaw angles, power, bike speed and lap times where relevant). This was just a test to see if Crr could be delivered in real time as well. It can.

See here for more details on that.

 

[Alex Simmons/RST]

If rolling resistance is so important, shouldn't we all ditch our racing 23s in favour of 25s

Because there are several factors to consider when choosing the ideal tyre for a given purpose.

e.g. outright speed in a road TT scenario is primarily a function of Crr and CdA (aerodynamics). Widening the tyre may gain a Crr improvement but worsen the aerodynamics. So one tests to see the overall impact of various factors considered most important for the set purpose.

In a crit there might be other considerations to do with handling characteristics, in training we tend to want better durability, puncture resistance and value for money, and so on.

 

[Giuseppe Magnetico]

I turn 40 today, last thing I'm going to do is talk to you nut jobs about tires!!

 

[Bustedknuckle]

I turn 40 today, last thing I'm going to do is talk to you nut jobs about tires!!

Happy birthday ya old fart!!

Nice day today, your employer gave you the day off right??

Go ride, gonna be beautiful in the 'republic'. Screw snow and winter!!

Gonna ride this AM..Merckx, tubulars, of course. Clinchers are for nancys.

 

[avanti]

If rolling resistance is so important, shouldn't we all ditch our racing 23s in favour of 25s

For a given tire presure the contact area with the ground will be constant but a different shape. A long narrow contact area improves traction and helps prevent aquaplaning in wet conditions.

 

[BroDeal]

For a given tire presure the contact area with the ground will be constant but a different shape. A long narrow contact area improves traction and helps prevent aquaplaning in wet conditions.

Bike tires do not aquaplane.

 

[Alex Simmons/RST]

I turn 40 today, last thing I'm going to do is talk to you nut jobs about tires!!

Happy Birthday!

 

[Moose McKnuckles]

I turn 40 today, last thing I'm going to do is talk to you nut jobs about tires!!

Happy Birthday! Turned 40 myself in July.

 

[oncehadhair]

No way in the world you can attribute that time split to a tire because of what an indoor lab test that doesn't recreate real conditions is telling you. A million other factors are defining those times.

I respect you Alex, you've put in a lot of time on and off the bike to promote the sport and you are to be commended. Several of the last 22 years I've worked this industry in marketing and consulting of wheel specific goods, and have sat across the table with companies that have laundry lists of professional race wins, sponsoring the who's who of racers telling me flat out "we have to lie if this is going to sell"! Keep that in mind when you empty your wallet for the sake of chasing the all mighty Unicorn. In the last few years I have since dissociated myself from the kind of work I used to do due to ethical reasons and ran back quickly to what I love to do most, is build wheels that make sense. I'm completely aware that I'm the Atheist in the room of a bunch of religious fanatics.

Gotto agree with you there.
No way can that time difference be claimed on tyres when there are so many other variables. Not a lot of science in that claim.
And rolling billboards will often have the sponsors name on an opposition product if the opposition product is perceived to be better.

 

[Alex Simmons/RST]

Gotto agree with you there.
No way can that time difference be claimed on tyres when there are so many other variables. Not a lot of science in that claim.

Yet if all the other factors are the same, and you get to make one change that improves speed, I don't know how you can make any other claim. That would be a lack of science. A lack of science would be to think that using a different set of tyres results in a rider trying more/less hard, or the wind conditions to be different etc etc.

For example, what if the change was a use of more aerodynamic wheelset? Does it mean that a claim same rider could have improved speed in his TT from such a change is also invalid? That would make equally less sense.

Hence why it bemuses me to suggest why one can't state that better choice of tyres can make a difference to an outcome, when it's very clear that they can (and do).

And rolling billboards will often have the sponsors name on an opposition product if the opposition product is perceived to be better.

Sure, it's well know pros ride all sorts of re-branded equipment, but what's that got to do with the point of testing which tyre is better?

I have no tyre brand loyalty, and have not pushed any particular brand or type of tyre here. All I have said is that tyre choice can and does make a difference to speed.

 

[Bustedknuckle]

Yet if all the other factors are the same, and you get to make one change that improves speed, I don't know how you can make any other claim. That would be a lack of science. A lack of science would be to think that using a different set of tyres results in a rider trying more/less hard, or the wind conditions to be different etc etc.

For example, what if the change was a use of more aerodynamic wheelset? Does it mean that a claim same rider could have improved speed in his TT from such a change is also invalid? That would make equally less sense.

Hence why it bemuses me to suggest why one can't state that better choice of tyres can make a difference to an outcome, when it's very clear that they can (and do).


Sure, it's well know pros ride all sorts of re-branded equipment, but what's that got to do with the point of testing which tyre is better?

I have no tyre brand loyalty, and have not pushed any particular brand or type of tyre here. All I have said is that tyre choice can and does make a difference to speed.

I think his point is...yes, take a bike 'thing', test it in controlled situations, and the results DO say one will be faster, better, lighter, stiffer, what-er than the other BUT, then put a person on the bike, who will exhibit varying degrees of performance, one day to the next, and the objective results get fuzzy.

Like wind tunnel testing a frame, bike and publishing the results..and then implying that if anybody gets on the thing, they will automatically be faster.

Well, they may be but because of whatever reason, they may be slower.

BUT objectively, it is most often seen by marketeers as a way to sell 'stuff'.

I don't think you could ever point to a piece of equipment and say definitively
it was responsible for any 'outcome'...unless that widget broke, of course, which effects outcomes all the time.

 

[acoggan]

I think his point is...yes, take a bike 'thing', test it in controlled situations, and the results DO say one will be faster, better, lighter, stiffer, what-er than the other BUT, then put a person on the bike, who will exhibit varying degrees of performance, one day to the next, and the objective results get fuzzy.

Absence of evidence is not evidence of absence.

 

[winkybiker]

Absence of evidence is not evidence of absence.

And controlling for other variables does not invalidate conclusions. Actually it is essential for conclusions to be valid. If on the basis of two real-world time trials results that a certain tyre was faster, I'd be correctly laughed out of the room. I have no experimental, nor statistical method of really figuring out why the times were different. However, if I control all other variables by testing in the lab, then my results are valid. Just because the noise of real world variables makes differences in tyre performance impossible to measure, doesn't mean they're not real.

 

[Giuseppe Magnetico]

Thanks for the HBD wishes! Now back to regularly scheduled programming.

Tire selection from brand to brand of comparable models is not determining the order of a podium, neither is aerodynamics, stiffness, or weight. Saving 50g somewhere on your machine over a competitors only means you're 50g lighter, nothing else. A slightly reduced frontal aero signature of a brand X frame over brand Y make look like a big difference in a wind tunnel, but the rider on brand X isn't guaranteed a win because of what a lab came up with, nor are their chances better because of it. Manufacturers know that most people believe what they see and read, so all this lab testing has done, even the independent ones, is create a bunch of dogmatic ninnys regurgitating lab results as if it were the New Testament believing that they're the Chosen Ones because a Conti GP4000s vs. Vittoria Open Corsa CX is a better choice on paper. The manufacturers spend millions on marketing and sponsorship every year to make you believe their whateverTECH is the best, and no matter how much marketing mADness you infuse into a sport like this races are always going to be won by whoever has got the best legs that day.

 

[M Sport]

A TT decided by less than a second and you clowns are trying to say it's nothing to do with Aero or CRR? lol

 

[Giuseppe Magnetico]

A TT decided by less than a second and you clowns are trying to say it's nothing to do with Aero or CRR? lol

Competitor A took a slightly different line in a few corners compared to competitor B. A had better positioning on the bike than B, A and B share almost identical athletic performance, the time is reflected there. A boffed his wife the night before, that's a no-no in this sport. Pick one, that's all it takes, has nothing to do with the gear.

 

[twothirds]

Competitor A took a slightly different line in a few corners compared to competitor B. A had better positioning on the bike than B, A and B share almost identical athletic performance, the time is reflected there. A boffed his wife the night before, that's a no-no in this sport. Pick one, that's all it takes, has nothing to do with the gear.

I have to slightly disagree with this. Although all those points are true, a constant is still a constant. Just because the result cannot be definitively or quantitatively attributed to a certain aspect of one's set-up doesn't mean that it wasn't a contributing factor. Saying a tire that's 1% faster doesn't matter is like saying a rear brake that is rubbing ever so slightly also has no effect. It may not have lost the race for you if you were a minute and a half down, but if you had lost it by a second and found out about the brake rub, I'd bet that you would definitely check that more carefully before your next race.

 

[BroDeal]

What I learned from this thread: That high falutin science stuff don't work in no real world. Dat only work in a lab.

 

[Giuseppe Magnetico]

I have to slightly disagree with this. Although all those points are true, a constant is still a constant. Just because the result cannot be definitively or quantitatively attributed to a certain aspect of one's set-up doesn't mean that it wasn't a contributing factor. Saying a tire that's 1% faster doesn't matter is like saying a rear brake that is rubbing ever so slightly also has no effect. It may not have lost the race for you if you were a minute and a half down, but if you had lost it by a second and found out about the brake rub, I'd bet that you would definitely check that more carefully before your next race.

There is no constant in cycling, not even the course or track. When you have a result like M Sport pointed out, less than a second, the bible thumpers will, like a knee jerk reaction credit the gear instead of realizing that those were actually two different people racing, not clones on different equipment. A bad set up is one thing, but to assume that decimal point of a sec finish is attributed to lets say, tire selection, to stay on topic, you may be a bit brainwashed. Everything, I mean EVERYTHING else would have to be EQUAL to declare that it was this or that piece of equipment won the race. So with reality as my witness, THAT IS IMPOSSIBLE!

 

[Giuseppe Magnetico]

What I learned from this thread: That high falutin science stuff don't work in no real world. Dat only work in a lab.

These are bicycles, not F1 cars or GP bikes. The "science" only goes so far in our world.

 

[BroDeal]

These are bicycles, not F1 cars or GP bikes. The "science" only goes so far in our world.

I put my trust in bro-science. It seldom fails but when it does, the results are often hilarious.

 

[Giuseppe Magnetico]

I put my trust in bro-science. It seldom fails but when it does, the results are often hilarious.

Like wet paint and bicycle tires?