Tire ideas

[BrianG]

I'm mainly interested in onroad tires, but something decent for any tire (truggy, buggy, etc) would be nice too. As long as I'm not pumping them with 30psi or something, they shouldn't bounce.

"Magic" foam sounds good, but probably not a viable solution at this time. My magic wand is fresh out of pixie dust.

I've thought of things like filling the tires with hotglue, to using fiberglass resin. Both of these would probably work, but would be far too heavy, especially the resin. Expanding foam may work, but in my experience, it tends to be uncontrolled and may expand too much.