Tire Rolling Resistance Study

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cyclenutnz
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by cyclenutnz

I've written about combined data a bit, as well as tunnel and crr testing.
In this article http://speedtheory.co.nz/mavic-cxr60/ I showed that it doesn't matter how aero the Mavic CXRs are when the tyres are so bad
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This article used Zipp tunnel data http://speedtheory.co.nz/marginal-gains ... -part-two/
Image

Again - aero far subordinate to CRR.

Issue with the velonews test is they don't included Conti Attack-Force or Vittoria Tri-Evo which are aero and good CRR. I would only race on GP4000S if the course had a lot of glass, otherwise they're too slow (though conti seem to update them so rapidly that this is always changing).

From testing on a 24mm wide rim I'd always look for the narrowest low CRR tyre I could find for TT/Tri purposes. And maybe trade a little aero for CRR/comfort for road racing and go to slightly wider than rim. My AR can't fit 25mm tyres so super low CRR 26mm tyres are not much help.

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kgt
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by kgt

Last couple of posts were really interesting...

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DMF
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by DMF

How is aero far subordinate to crr when even the attack 22 vs gp4000 25 is in the ~7 watt range? Doesn't seem far off of crr differences when looking at top tier tires?

bm0p700f
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by bm0p700f

This is quite interesting. But the results are not so clear.

Other tests have shown tubeless tyres to fair very well so should I be using specialised tyres. The potential differences are bigger than i thought.

joepac
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by joepac

What annoys me is that they used butyl tubes in the cheaper tires further handicapping them. The specialized turbo pro is pretty close to the Sworks turbo, and that's with a butyl tube in the "inferior" pro. The difference would be much less if they would have tested both with latex tubes. Why not save $20 if you're only losing a watt or two? Almost suspicious how that works out... :roll:

This is why you only test one variable in rigorous scientific tests and minimize/eliminate all other confounding variables :smartass:; it makes the data and results more useful because it is a direct comparison (what a crazy idea :lol: :roll: ).

I get they are trying to be more "realistic," but how many people actually race on latex tubes? :noidea: I race and train on butyl because it is more puncture resistant. Everyone I know does the same (except for the people running tubulars and using gatorskins totally defeating the purpose).

BrianAllan
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by BrianAllan

I didn’t catch this thread and started another. Is anyone else perturbed that they took the time to test clinchers and tubeless, but omitted tubulars? They didn’t even bother to acknowledge the omission in the article.

And as I said before, anyone who cares about 5 watts in the context of racing, is probably running tubulars. The fact they didn’t test any of the nicer tires with butyl tubes for a comparison between butyl and latex is also just idiotic and probably intentional.

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by bikeboy1tr

[quote="BrianAllan"]I didn’t catch this thread and started another. Is anyone else perturbed that they took the time to test clinchers and tubeless, but omitted tubulars? They didn’t even bother to acknowledge the omission in the article.

I was kind of perturbed at this issue as well. Most everything I run is tubular.
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F45
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by F45

They said it takes half an hour per test. For the price I paid, I'll take what I can get and be happy.

cyclenutnz
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by cyclenutnz

Clinchers are easy to change. Have to add a lot of prep time and several days of cure time to test tubs properly. It's not easy to do fair testing of tubs.

And the people who care most about fractions of a watt are usually running clinchers now.

stoney
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by stoney

Clinchers are faster than tubulars: https://www.youtube.com/watch?v=0ovYHQ35-5o

sungod
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by sungod

that br 'test' is a joke

there're special purpose tyres, such as the ones tony martin sometimes uses, but they're really pared down, so the risk of flats is higher, probably don't get too many km out of a set either

as earlier posts point out, there's more to it than crr, different tyres will give different results on different rims, and pressures, and road surfaces etc.

going for a few rides in uncontrolled conditions on tyres that are clearly not the best of either construction, which is the br 'test', is no basis for rational decision

bm0p700f
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by bm0p700f

Latex tubes in my experience at least puncture differently to butyl tubes (they may be more puncture resistant but that is had to prove). Latex tubes get a tiny hole and go down slowly mostly whereas butyl tubes seem more likely to get a fast puncture.

that test you linked too has so much wrong with it should not be on the web. Average power maybe the same but power at different points may be different this may affect the time. The comparison is between one tub and one clincher and therefore you cannot conclude clinchers are "faster" than tubs anyway. Wind conditions will not be the same and even small changes can add up to seconds. It is not a result that should be used to make any decisions about which tyre to pick. Besides no-one picks the Competition tub for low rolling resistance it gets pick because it is quite durable and has lower rolling resistance (I hope) than the conti sprinter.

KWalker
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by KWalker

Jesus christ

One of two mainstream publications

They use .jpeg for their main table. So it is blurry on large displays.

Then, their graphs.

Excel. Are you f'ing serious? Not one person there knows how to make better charts, tables, or graphs.
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BrianAllan
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by BrianAllan

cyclenutnz wrote:Clinchers are easy to change. Have to add a lot of prep time and several days of cure time to test tubs properly. It's not easy to do fair testing of tubs.

And the people who care most about fractions of a watt are usually running clinchers now.


Is it really that hard to set-up 3 or 4 pairs of tubulars for a test? No. No it's not.

Fractions of a watt? Huh? Like Wiggins during the hour record? Is anyone running clinchers in the TdF to your knowledge?

I think I heard something about Tony Martin running clinchers in a TT stage once, but it's quite uncommon if it happens.

spartan
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by spartan

really...

vittoria next gen graphene tires.

their own testing reveals the tubeless version is the FASTEST...discussion over..

sworks tires are made by vittoria in there thailand factory. excellent tires but fragile.

read tour mag issue where they compare grand prix vs new spec/schalbe pro one .
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