geek49203 wrote:
Cause the tires do act as springs, as (of course) do the springs above them. If I lower the spring rate of the tires by letting out some air, don't I transfer the spring function to the tire from the springs, and probably some funky (bad) things would result?
On the other hand, if I put in softer springs, the spring function would remain with the springs, albeit a bit more 'cause the springs are springier?
Yup, if you are running less than say 25 lbs, you have too stiff a spring and/or damper and you are relying on un'dampened air springs, ie; the tyre, to do your suspension work, not good.
For a comparison a Lotus Elise is 1600lbs (650 fr/950 rear) and ideally runs around 25/28 and they would be one of the lowest pressures for a production car in the world, I happen to know that Smart's are 29psi all round (they are also 1600lbs but would be softer sprung and higher sidewall than a Lotus).
geek49203 wrote:
Then again, the shocks have something to say about harsh rides too I hear....
Typical common shocks simply force oil through a set sized hole so hitting sharp edges can be too much attempted flow through the hole. Open up the hole and then the oil flows too fast at slow speeds.