There is no weight on a leaf spring shock when the car is not in motion...static. During acceleration the shock is carrying some weight. Force is trying to collapse the shock. Valveing eventually allows that to happen in a controled matter. If/when the shock "unloads" so does the suspension. On a coil over the spring attachs to the body and shaft. Not only is the shock transmitting the weight the coil is carrying to the mounting points the force from the shaft/plunger in the body is also transmitting its load through the shock via hydraulic or air pressure. Static not as much but under acceleration much more.