Well Bob, I also beg to differ! The backspacing of a rim has nothing to do with the inside bead lip where the tire seats, it is always measured exactly as shown above, from the rim edge to the mounting surface! Why would the inside of the bead lip have anything to do with the backspacing of the rim?? They don't take into consideration the sidewall bulge of the tire either, with has a bigger effect on the clearance issue of backspacing than the bead lip could!! That's because the rim manufacturers are giving you the actual clearance numbers of the rim, and that has nothing to do with the tire!
