Backspace and offset dont seem to make sense, US rambler mags
Backspace is measured from the outside lip of the rim to the wheel mounting surface, so it includes the 1/2" of extra width outside of the tire mounting surface. An 8" rim is actually 9" wide outside lip to outside lip, it's 8" from tire mounting surface to tire mounting surface. So an 8" wide rim with a 0 or 1mm offset has a 4.5" backspace, an 8" wide rim with a +13mm offset would have a 5" backspace.
Backspace is measured from the outside lip of the rim to the wheel mounting surface, so it includes the 1/2" of extra width outside of the tire mounting surface. An 8" rim is actually 9" wide outside lip to outside lip, it's 8" from tire mounting surface to tire mounting surface. So an 8" wide rim with a 0 or 1mm offset has a 4.5" backspace, an 8" wide rim with a +13mm offset would have a 5" backspace.
