Quote:

If you want to get into the mathematics look up Hooke's law of elasticity. The formula governing the mechanics of the spring is F=-kx (k is the spring constant, x is the distance the spring is compressed or stretched, F is the force required to compress or stretch the spring). The minus sign in the equation is there because the spring will exert a force opposing the force trying to compress it so that it reaches it's natural state of equilibrium.

So, when you add preload you are pre-compressing the spring (the lenth of the shock doesn't change but you can see grooves that show you how far you've compressed the spring, right?). By preloading you are adding a force component that opposes weight (payload) that you add to the bike. This way they operate the same way that they do if there is a small payload and no preload. This also explains why they feel more rigid if you add preload but no payload.

In other words, when you add preload the spring creates a force that pushes up from the ground. When you add payload it exerts a force on the spring that pushes down to the ground due to weight created by gravity. If preload is higher than payload, the springs feel rigid because there is not enough weight to counteract the opposing preload. If payload is higher then the springs operate normally by absorbing the potential energy created by gravity (by bouncing around uneven road surfaces) until the spring is fully compressed. Hope this helps, I tried to put it as close to layman's terms as I could.



That is shocking.

(and hard to absorb)

And you may see me tonight With an illegal smile J. Prine