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Old 07-01-2013, 08:34 AM   #1 (permalink)
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Tire pressure vs rolling resistance - cycling in the rain

Hi Guys,

I've just found an article saying that decreasing tire pressure can actually lower the rolling resistance.

What do you think of that?


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Old 07-01-2013, 09:55 AM   #2 (permalink)
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Bicycle tires. whole 'nother ballgame compared to car tires. Very narrow tires... very light... very high pressure.

This probably explains it nicely:

Tires should not be tested without a rider on the bike. Most of the energy is lost in the rider, as vibrations cause friction in the body’s tissues (suspension losses). That is why testing in the lab can be misleading. In the lab, higher pressures roll significantly faster, but on the road, the suspension losses increase with higher pressures and cancel the advantage of the reduced tire deformation.

Last edited by niky; 07-01-2013 at 10:19 AM..
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Old 07-01-2013, 12:12 PM   #3 (permalink)
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This is a nice methodological point for all of us (riding bikes and driving cars) doing testing: "Did the results represent real differences in tire performance, or was there too much noise in the data? After all, even slight changes in rider position, a tiny gust of wind, or other factors might influence the results. To check this, Mark, who has a Ph.D. with a Minor in Statistics, did a sophisticated statistical analysis. He found that our results were “statistically significant.” (Basically, he compared the data from the three runs of the same tire with the data from different tires. The variations between runs with the same tire were much smaller than the variations between different tires.) This means we really did measure differences in tire performance. (Many studies skip this step, but it’s crucially important.)"

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Old 07-01-2013, 04:17 PM   #4 (permalink)
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Lennard Zinn is a recognized cycling expert and other noted authors such as Edmund Burke in "High Tech Cycling" deal with the high pressure racing tires used in competition. Tire internal deformation has a big effect on rolling resistance. What we are seeing now is the advent of tubeless tires in mountain bikes which have much less rolling resistance than tires with tubes. Selecting the tire for your riding application should include consideration for your weight and a tread that allows for water to move out of the tire patch area efficiently.

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