the concept that folks that folks unfamiliar with wheels have trouble grasping is that it isn't the bottom spokes that hold the hub up, nor is it hanging from the top spokes. It's the failure of the lowest spokes to pull the hub down as hard that's the key.

By analogy -- two evenly matched teams are playing tug o war and neither is winning as they both pull equally. What would happen to the middle of the rope if some big gorilla ran into the back of the last man on one of the teams?

Can't visualize it, try this experiment. You need 4 people and a length of rope. Tie the rope (the spokes) around the waist of one person (the hub) and have two others (the rim) pull at the ends tiug o war style, but they shouldn't try to win. Now have the fourth person (the bump) body check one of the rim people from the back. The other two should instantly learn how wheels work. Change places and repeat until everybody understands.

Likewise the unloaded wheel is in equilibrium with all spokes pulling on the hub. When a load is added it replaces some of the tension on the lower spokes, so the system remains in equilibrium. When the wheel hits a bump the tension on the spokes in the impact area is reduced momentarily upsetting the equilibrium so the hub is lifted.

In trying to understand a wheel, don't think of added tension, but of the locally reduced tension and how it changes the equilibrium.