Originally Posted by
jonathanb715
In a weird way, that was exactly my point. Think of your bicycle chain. you can have a circular shape with a circumference pi*2*r. Now take the chain and flatten out part of it, like a bicycle tire, but keep the rest circular. Do you really think the circumference just changed?
The tire circumference doesn't change. The
rolling circumference does.
Michelin says so.
http://www.michelinman.com/glossary/
Rolling circumference
The linear distance traveled by a tire in one revolution (its circumference). This can vary with load and inflation.
Hopefully, Michelin is a authoritative enough source!