Tire pressure vs rolling resistance - cycling in the rain

[AndrzejM]

Hi Guys,

I've just found an article saying that decreasing tire pressure can actually lower the rolling resistance.
Tech-Talk-Tire-Pressure-in-the-Rain

What do you think of that?

[niky]

Bicycle tires. whole 'nother ballgame compared to car tires. Very narrow tires... very light... very high pressure.

This probably explains it nicely:
http://janheine.wordpress.com/2012/0...ance-of-tires/

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.

[California98Civic]

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.)"

[Grant-53]

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.

[Vekke]

Found this kind of study on truck tires and pressures:
https://www.researchgate.net/publica..._Surface_Mines

[matt36415]

Very interesting, these vehicles would be running on dirt roads, have massively thick tyre walls, low speeds. Mountain bike racers usually use the lowest pressure they can without damaging rims or getting flats in order to increase traction and reduce rolling resistance over uneven surfaces (hard tyre = lifting bike over every bump, soft = tyre deforms and bike lifts less) but I suppose these trucks are so slow, tyres so massive that there isnt any relationship between them.