Is there a known coefficient of friction that's generally accepted between the salt surface and a rolling wheel? I realize that the composition of the wheel in contact with the salt surface is part of the equation (rubber compound or solid metal), but as the aero forces increase, you're essentially pushing against the wall, and tire slip could occur if the power applied exceeds traction. Also, does the salt surface shear, meaning that as you apply more power, is there a tendency for the surface to slip over underlying layers? How about this - is there a rule-of thumb concerning the unit loading of the tire/wheel combination? If you had a very narrow or crowned wheel, then your vehicle's weight would be concentrated in a very small area. Is it possible to overload a wheel so that it creates furrows in the surface, and in doing so, causes the rolling resistance to actually increase? I understand the fact that traction isn't a straight line graph with vertical loading, but I wouldn't want to make the wheel thickness excessively thin, either. Maybe the rules have minimum width or unit loading requirements and all of this is a moot point!
Thanks in advance to any replies!