Hi,



Sure. One thing to keep in mind though is that Continental doesn't count TPI the same way Vittoria or say, Veloflex does.
Anything truly "Open Tubular" usually comes with a relatively high (true) TPI count. IME the difference of using a latex or butyl inner tube with those tyres is very obvious.

With lowish TPI count tyrees (clincher mostly) the effect of the latex inner tube will be masked to insignifance by the stiffness of the sidewalls. Hence pretty useless bar the occasional weight savings.

Ciao,

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Hi,



Sure it's a marketing ploy but that does not make it false per definition. If ever you'd see a clincher advertised as an "Open Tubular" when there is no evidence of a tubular brother tyre then we could all shout "foul play".

Ask yourself, how many true clinchers are there with a high true TPI count? Not many if any at all, I reckon.
It's only lately that companies such as Schwalbe took the tech of clincher building to a higher level (let's just say they're trying hard for the moment) yet all of their know how came from a tubular manufacturing company they took over.... Irony?

See where I'm going?

That said, I do not think TPI count is overrated. Unfortunately it's often misrepresented to put it mildly....
Combine high TPI count and modern compounds and you'll inevitably end up with a very fine tyre. High tech compounds combined with low (true) tpi count tyres OTOH will not show fine rolling resistance figures unless you go for the wider ones.

Can't have your cake and eat it too, right?

Ciao,

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Some 120-127tpi tires roll on par with 270tpi tires don't they? Michelin's Pro Race series comes to mind.

Except they shred when they hit the pavement. Cuts, nicks, flats, wear quickly. Do roll nice though.

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2007 Bianchi 928 Carbon Lugged- SRAM Rival-17 lbs.

IMHO only hight tpi clinchers from Vittoria, Veloflex even Challenge (with latex tubes) come close in ride quality to tubulars. Any other top clincher I 've tried gave me a feeling I would describe as 'wooden' or 'dead' or 'harsch'. I realized that immediately the first time I rode an 'open tubular'.

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The RR tests I've seen don't support the idea that TPI - perhaps I should say claimed TPI - is as important as some people here claim.

It may well count for something, intuitively it makes sense that it does, but the data doesn't support it's cheerleaders.

And there's no testing of manufacturers' stated TPIs. Believe them on that when we've learnt to take all the other marketing with pinch of salt? How odd.

High-end clincher tyres undoubtedly feel a bit different to each other, but having ridden almost all of them I find the correlation between claimed TPI and comfort/handling/perceived RR to be weak or non-existent, at least with a butyl tube

"Open tubular" makes me laugh. Perhaps clincher tech will keep improving to the point where those manufacturers' tubulars become "closed clinchers".

Or the GP4000S etc. etc.

Hi,



RR tests do not tell you in an explicit way how well a tyre will roll when the load it sees is modulated. Picture roughnes of the road surface and you may see how a high TPI count tyre + latex inner tube will be able to track such surface better hence maintaining low RR longer.



That's is absolutely correct in some cases. Most of the currently available "Open Tubulars" do however stem direectly from tried and proven tubular design (hence the marketing ploy) and do have (mostly) a much higher TPI count than most clinchers do.
They are popular because of their high quality and superb performance but other than that they're just another clincher, technically spoken.

Ciao,

_________________
Being a snob is an expensive hobby.

The various RR tests that have been done are no doubt imperfect, though along with the unquantified user experience are the best "data" available.

Having tried all flavours extensively I'd love to be able to report I've found 320TPI vittorias significantly faster ... but sadly not. They're OK ... nice enough but not the best. The terms in which some people glowingly describe the performance benefit of such tyres must surely equate to 2 or 3km/h?

That said, I do buy into the basic point that a tyre that deflects more will, up to a point, be faster than one less supple.

GP4000S for training/racing works for me.

That is quite true. The loss is via hysteresis which is only loosely linked with suppleness. Hysteresis is effectively like a suspension damper, so could provide the sensation of a smoother ride even though it is sucking energy. The Conti Black Chili tread compound resulted in a large drop in Crr, but seems to be harsher in ride quality. I suspect that if this tread compound was used on a Veloflex casing, it would be even lower for Crr, but it is also possible that the Veloflex casing itself has little or no advantage over the Conti casing.

Me too. I have had awesome luck with the GPs. Train, race, and generally beat the hell out of them every day. I rarely flat, pinch.

I think I may mount a set of the Force Attack combos on a set of race wheels though.

Hi,

A definition of hysteresis:

http://en.wikipedia.org/wiki/Hysteresis

And the part related to this topic:



How you can translate this and say that high tpi count does not have an impact is beyond me. Granted, you have to view all this in context , context being road surface, rubbber compound formulation, tyre pressure, rider weight, volume of air present, etc.
But surely anyway you look at it, TPI count will have an impact.

Then this also ties with the comfort factor which will also have its impact on the rider and the final performance. Has to...

Back to square one?

Ciao,

P.S. Yes, an imaginary cross between Veloflex's finest and a Conti Comp may well make for a very fine tyre.
P.P.S: Some should rally try riding a silk tubular so you'd understand the impact of TPI count on ride quality.

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Vittoria Diamonte Pro Light Tires 170g and durable

These diamante pro lights are 220tpi nylon.
The tires on my mavics are 127TPI nylon and they are very smooth and comfortable (surprised me too!).
My conclusion is that TPI alone is just a number when comparing tires of different materials, construction method etc.. apples and oranges.