looks like that skid patch formula only works with simple numbers or something. I found another one that nails it every time and built it into the worksheet.

Now there is a pulldown with some common approximated tire diameters and you can still enter a custom size if you need to.

You can specify a range of gear inches and/or gear ratios to be displayed in bold in the results.

You can specify a cadence in rpm and/or wheel speed in mph to have the other value calculated for each combination.

If anyone has other ideas, blurt 'em out.