unfortunately, on the dirt bikes, there is no fork preload adjustment, without shimming the spring. also, the stock fork springs tend to be on the very soft side. recently having re-sprung my forks, i would reccomend going to the race-tech website and run through their custom suspension routine. it'll reccomend a spring rate. it made night and day difference for me. i sure wouldn't ride stock springs on closed course pavement, and now i know i probably will always make appropriate suspension changes on my dirt bike. rear shock seems to accomodate my weight pretty well. good luck dialing it, and have fun. oh yeah, you would'nt ride on the track without a steering damper, would you? thats another thing i added, big bucks, but enormous gains.
$.02
mo