There is a formula to setting preload but it can be messed with it has to do with the SAG or how much the fork sinks when you hop on. That is useful but is very general. I have a zip tie on my fork to see how much travel I actually use. If you don't use much travel lower you preload. If it looks like you are on the verge of bottoming over every drop then up the preload. Damping controls how fast the fork bounces back. If damping is to slow you get a pogo stick front. To much and the fork will stuff and bottom out easier. Hope that helps.