how do i figure out offset of wheels?

[XXX4life]

yes i searched, i need to know how to figure out the offset of a set of wheels i wanan buy, the guy selling them doesn't know the offset and they aren't stamped on the wheel, please help thanks

[Var]

measure in/out from the center if the rim.

If the rim is 8 inches wide, you measure from the center(4 inches) in, or out if it has negative offset.


http://www.diamondracingwheels.com/images/offset.gif

[XXX4life]

measure in/out from the center if the rim.

If the rim is 8 inches wide, you measure from the center(4 inches) in, or out if it has negative offset.


http://www.diamondracingwheels.com/images/offset.gif
i don't get it? i feel really stupid :(

[Andrew Bohan]

the rim has a centerline, an "equator" halfway between the front and the back.
the rim has a mounting surface, the part that touches the brake rotor hat.
the offest is the distance, in mm, between the centerline and the mounting surface.

if the mounting surface is behind the centerline, the offset is negative.
if the mounting surface is in front of the centerline, the offset is positive.
if the mounting surface is on the centerline, there is no offset. the offset is 0.