[Land-speed] Contact patch size

Elon saltfever at comcast.net
Mon Nov 17 17:28:03 MST 2008


Skip I am only responding to Jon's definition. He says 'patch' is the square
inches of rubber in contact with the ground. Using that definition the patch
area will vary with surface density or hardness. Keeping the load and
pressure the same, apply the tire to two different surfaces. In the morning
the salt is hard, dry and cold. In the afternoon the salt is hot, soft and
moist. Two different surface characteristics but with exactly the same tire
load and pressure. The latter surface will have more patch area because the
tire will imbed or sink further into the surface more than the former
condition. Even though we are talking thousandths of an inch here the patch
area changes with the medium. The more the tire sinks in, the greater the
rubber area in contact with the surface medium, no?
-----Original Message-----
From: Skip Higginbotham [mailto:saltrat at pahrump.com]
Please explain to me how patch size "obviously" varies with surface
medium. I assume here that you are not talking about mud. We don't
run on mud, snow or sand.


More information about the Land-speed mailing list