brian wrote:I guess I am assuming that some weight is transferred across via the spring. If there is an upward push on the outside tire doesn't that translate to a downward push on the inside tire. The spring is pushing on something to be resist compression.
I go along with Brian H. on this, yes, definitely, some weight is transferred across the spring, but only so far as it's the means to hold the car up. If you replace the spring with a bar in the zero roll resistance setup, the weight transfer is identical, so it's independent on spring rate.
With the zero roll resistance single spring suspension, the spring can only apply the same force to each tire. If you hit a bump with one tire, the other one feels it as the force is equalized (I'm taking about a zero mass component suspension). Here a different spring rate will soften the jounce differently, but the tires get the same force added by the jounce. In this case, the effect of the jounce is shared across the spring to each tire equally. Maybe this is what you've been talking about.
But, this is different than weight transfer due to cornering. If we consider cornering being similar to tilting the car (it's not the same, just similar), the COM comes through at an angle, and the additional weight transfer is provided mechanically through car. In other words, if we just consider the joint between the transmission and the axle tube of the outer tire, when the car is not cornering, there is no sideways force along the axle (let's neglect the suspension arms being on angle because the suspension arm on each side has the opposite force, or we can make them vertical, in actuality so they do not contribute to side forces). Once we go into a corner there is now a sideways force along the axle tubes. This force is what causes the weight transfer. It adds on the outer side and gets less on the inner side. The spring, as Brian H. said, is just holding the car in position, and its role has not changed, nor has the force on the spring changed if the car is on a flat surface.
Again, this is only for zero roll resistance monoshock suspension we run.