Contact Area and its Relation to Friction?

[Paul Copioli]

QBranch (aka Alex) wants a definitive answer and he will get it right now.

Static friction force does not depend upon surface area. Static friction force does not depend upon surface area. Static friction force does not depend upon surface area.

This assumes one major thing: The surface pressure between the two items is low enough to not cause material failure at either surface (wheel/tread or carpet).

You must make your wheel width wide enough to not rip up the carpet and not yield your rubber (at least, too much). You should design your wheel width to not fail either material. Once you have done that, the width doesn't mean squat.

Alan is correct about dynamic friction: surface area plays a bigger role.

I have posted numerous times on this and the width does not matter.

I will not argue with any of you about this. I am as certain as can be on this issue ... believe me.