Thanks for that update, Jeff. I had just downloaded it and tried it for the first time. For some reason it blew up when I input my 5" wide Bonneville tire. I'm sure it was user error.
Based on what you say it looks like a motorcycle could easily fit into the limits and it would be a useful program. To get CdA, Rockstar could do a
coast-down test and get very accurate results since it includes area as well as Cd in the result. Cost-down tests are extremely accurate if done correctly (but it is not easy to be accurate). I think the archives may have something on a coast-down or Google it. Allowing for relative wind and the tire-to-ground contact are necessary for a good test result.
EDIT: I just checked my program (ver 3.2.2) and the tire
width in inches is 6.5 - 22. That eliminates just about every LSR Goodyear. My download was 2 days ago and I'm assuming it is the latest version. What version do you have Jeff?