Thanks again. I guess my best bet on determining the rim width is not going to be trying to deduce it from the tire size, but by getting out a ruler! It does sound like I can use your math to dtermine the correct tire to put on it to keep the overall wheel diameter the same, regardless of rim used, so my speedo stays correct. One last question, where on the back is the offset stamped? I have a lot of tree sap to deal with so I need to home in on it!