Post History

This isn't a direct answer, but something that should be cleared up.

<blockquote>With a trike in general it would seem the end with two wheels is going to have half as much load per tire, with twice as much surface area, as an upright.</blockquote>

Yes, each wheel will have half the load.  However, the overall area contacting the road is still the same.  Road contact area is basically proportional to load at a given tire pressure.  Assuming all three tires have the same pressure, the two separate tires will each have half the contact area as the single tire, resulting in the same overall contact area.