Wheel Spacing Ratios

[Deke]

I have seen a couple of these discussions pop up lately:

http://www.chiefdelphi.com/forums/sh...d.php?t=139936
http://www.chiefdelphi.com/forums/sh...d.php?t=139171

Past discussions:
http://www.chiefdelphi.com/forums/sh...ad.php?t=86443
http://www.chiefdelphi.com/forums/sh...d.php?t=129521
http://www.chiefdelphi.com/forums/sh...d.php?t=116836

There are a few white papers and calculators out for this is well. I wanted to take a more simplistic approach to this and just look at wheel spacing ratios.

Assumptions:
- All wheels are loaded and spaced evenly
- 6 wheel no drop has 2/3 effective length of 4 wheel
- 6 wheel drop has 1/2 the effective length of 4 wheel
- 8 wheel 2 center drop has 1/3 the effective length of 4 wheel



It seems the KOP drive is as good of standard as any in FIRST, which has had a 1.8 width to length ratio over the years. The current no drop KOP wide configuration has around a 2.5 with the 2/3 effective length of the 6 wheels. The drive in a day (DIAD) from vex appears to be around a 2.3 width to length ratio, but they have a few patterns to choose from.

Is the 1.8 number an acceptable minimum for width to length wheel contact patches?
Should there be a maximum width to length ratio?
Does center drop matter with length? (the opposite wheel clearance is twice the drop distance)