Okay... so you push down on the top of the wheel, the sides want to bulge out, and that places the spokes radiating to the sides in greater tension. I *think* the hub still 'hangs,' just from different points on the wheel.
Complicating this is that unless we're talking about radially-laced wheels, the tensions in questions are vectors at at some tangent angle. ( probably didn't phrase that right, I'm terrinble at maths).