Quote:
Originally Posted by Ecky
My understanding of this is that "faster" on bicycle tires isn't strictly rolling resistance. Having very hard tires increases rider fatigue, even if the bike rolls easier, so you find people can't put as much power to the road for as long. It's a human limitation which motors do not share.
Correct me if I'm wrong, but a smaller contact patch will result in less rolling resistance, and there are several ways to achieve this. Adding pressure reduces sidewall flex, and sidewall flex eats less forward motion. However, sidewall flex is also what gives a suspension effect, because it also eats vertical motion. The reason we use hollow tires filled with air is not for speed, but for comfort, and to prevent irregularities in the road from tearing our vehicles to bits.
All else being equal, it's better for rolling resistance if the contact patch is longer and less wide, so if you're shooting for lowest rolling resistance possible (often at the expense of ride quality) you'll want very narrow tires with a relatively large diameter - approaching the shape of a bicycle tire.
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These are lab test results, considering only RR, not rider fatigue. The difference is even greater with a rider and suspension losses.
A smaller contact patch has a lower RR in theory. Even the smoothest concrete is too rough for that to work in the real world.
Tech FAQ: Again, bigger tires roll faster! | VeloNews.com
EM style coast down testing:
https://janheine.wordpress.com/2012/...ance-of-tires/
Shape of Contact patch:
FLO Cyling - The Contact Patch... Why Wider is Better
Remember also CapriRacer's various posts on the subject, I used to be skeptical too
The i3 could be an example of an evolutionary dead end. No OEM since has gone that way.