Ouch... Wheels don't fit...

[BBC71Nova]

I'm slowly starting to appreciate the value in paying someone to just build the car and deliver it. True, the actual time/labor is part of it. The most value has to be with not having to deal with all the stress and frustration of stuff not fitting.

So I got my wheels in this week. Very nice. Only one problem. I just mocked them up and THEY DON'T FIT! . I had thought and was led to believe that using a wheel with known size and backspace was best method of determining what size new wheels to get.

I have a set of 15" X 10" wheels with tires mounted. The wheel is listed as a 5" backspace wheel. That setup fits fine but could stand to be 1/8" further inboard. With the new setup I went with an 18" X 11" wheel. Simple, right. Split the 1" difference in width yielding 5.5" backspace plus the extra 1/8" and voila new wheel needs to have 5 5/8th backspace to fit perfectly. NOPE. Apparently not.

So Either Weld or Vintage one measures wheels differently. From what I can tell the Weld wheel backspace is taken from the inner bead seat. The Vintage wheel is from wheel edge. The bead lip is ~1/2" and that roughly matches how much I'm off.

Fail! No telling how much this is gonna cost. There's gonna be a Nova bonfire before long.

OK I'm done venting

EDIT: more details later in the thread. Both Weld and everyone else does measure the same as you'd expect. After taking better measurements the variance in the Weld wheel is only 1/8" yielding 5.125 actual backspace. Probably considered within tolerance. Wheels spec'd out as planned aside from that. Just that after mounting I can see clearly that an additional .25" backspace would be ideal. Lessons learned: 1. Take actual measurements of the wheel you are using instead of trusting published specs, 2. within reason error on the side of more backspace since you can space them out later if necessary.