Seems to be a misconception with preloading forks.

[Huffa]

When preloading forks, all that you are really doing is adjusting your chassie ride heigth. You want some sag with you off the bike (called static sag) as in 3/8 to a 1/2" or your forks will top out when leaving the ground.

In all ATV's, C's and bikes you want static sag F&R. You can't make a spring any stiffer then it already is. By preloading it your just riding higher in the travel a bit which will help the ride plushness. It's going to bottom out over a jump exactly the same whether you preload them or not thopugh. Preload them to much and the spring will coil bind before you use up all the travel.

Bottoming out too much usually means a stiffer spring, heavier oil or raise the oil level a bit.

Feel free to add or correct me on anything I said but that's what I had learned over the years.

[250rAL]

Preloading forks is the same as adjusting the preload on shocks. You can adjust for rider weight and it does make the fork more resistant to compression. You see, the spring doesn't resist at a constant rate. The farther it is compressed, the more pressure it takes to compress.