Alright, Crenwelge . . . you just brought my brain to a stop.
Why does weakening springs increase caster? In my mind, with the axle mounted below the springs, and the spring shackle at the front of the frame, the springs weakening - flattening, yes? - the shackle pivots forward, and, pivoting on the rear spring hanger, the axle "tilts" toward the rear, which is "increased" caster, isn't it?
Of course, the very fact that I think this is so should be proof positive it works the opposite way . . .
-Michael
