# Clincher or tubulars for time trials?

Discussion in 'Cycling Equipment' started by Maverick, Mar 9, 2005.

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3. ### artmichalek New Member

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Further underscoring the wretched confusion that results from the English system. A kilogram is a unit of mass and a pound is a unit of force. Force per area is pressure, mass per area isn't. The kilogram-force was rather prudently rejected by the ISO in 1955. It was defined as 9.80665 Newtons, which is exactly the kind of clumsy conversion factor that the metric system was developed to avoid.
Proper notation aside, I have yet to see a tire pressure gauge that reads in kilograms-force/cm^2.

4. ### Peter Verdesi New Member

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While we're on the subject of tubulars or clinchers, I was wondering if anyone has heard of problems when mixing the two (like mixing bias ply with radials on a car)? I've got a set of Zipp 909 tubulars on a race bike (triathlons) and I could foresee an event when I get a flat and need to swap out wheels quickly. I've only got one set of tubulars (the Zipps) the the replacement would have to be a clincher. For what it's worth I would have prefered to get the Zipps in a clincher but the price was right for tubulars.

5. ### RC2 New Member

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Never heard of problems mixing tub's/clinchers per se. Mixing two different types of tires w/different tractions can result in some handling weirdness tho.

6. ### Peter Verdesi New Member

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I figured it might get a bit weird on the bike if you have a mix. There is a big pressure difference between the tubulars on the bike now and any potential clinchers (170-120 respectivly). I can't imagine that it would be a problem at lower speeds but going down a hill at 50 mph or around a sharp turn would magnify any differences. Thanks for the reply.

7. ### ct2 New Member

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Whoa there, sounds like you may know too much for your own good!

8. ### HotLips New Member

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I have used tubular on my race (triathlon) wheels (Zipps) and only ever had one flat with them, they are great in the dry and fast, and not to difficult to put on (if you get the right glue). Only down side, some can be real dodge in corners when wet because of high pressure, and can be expensive, but so can good clinches.

9. ### jerryz New Member

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You can run the numbers on clinchers and tubs for yourself over at analytic cycling. Tubs come up with more rolling resistance. You can even compute how much faster you would be, in time, over a length, with the different tires. Nice little exercise. Does make one wonder why the big boys are still on tubs though? The science would appear to not be on their side.

10. ### dhk New Member

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In the above posts, there is a discussion of the base data used by Analytic Cycling to feed their calculations. Unless there was some more data used that we haven't seen, would say some valid science questions exist.

Personally, I wouldn't put much credence in the results the calculator spits out. Would think results of side-by-side coastdown tests on real roads could be a better source of comparison data.

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