Does sway bar increase spring rate in coilover suspension?
 

All,

In a coilover type suspension, does adding a thicker sway bar increase the spring rate in the suspension in situation like running over a rock which cause compression only on one side of the car?

thanks,
anthony

Technically yes, running over a rock with one wheel would load the sway bar and increase the effective spring rate on that corner of the car. The type of spring - coilover or torsion bar - is irrelevant.

What he said.

If only one wheel hits the rock, then the sway bar is only giving half its rate in roll. In roll, one side goes up and one side goes down so the bar twists twice as much and makes twice the force.

Regardless, sway bars always transfer weight from one side to the other. When going over a one-wheel bump, the wheel that hits the bump feels half as much force as it would in roll, but that force still comes off of the other wheel.