I'm not really sure where your numbers are coming from; are you assuming a certain length, width, or frame perimeter as constant, and what are you varying to get the different categories?
The KoP chassis does have a drop center, and can be constructed to several different lengths, which as I understand it, would change your numbers considerably.
The bottom lines as far as I can see are that:
- For most solid tire materials, the track to "effective length" must be significantly greater than 1.0 to turn (1.25 to 1.50 are good enough for most purposes, 1.8 is rather high).
- The center drop must be enough that you can only have significant weight on two axles. Longer robots with softer (pneumatic or sponge) wheels on soft carpet will require more drop than a robot with a shorter wheelbase, solid wheels, or which drives on firm carpet.