With a normal (Non-slipper) clutch you have to blip the throttle to match the RPMs when you downshift. If you just engage the clutch without rev-matching it will jerk the rear wheel which is bad. A slipper clutch doesn't engage as soon as you release the clutch lever (it "slips") and brings the RPMs up without jerking the rear wheel, and you don't have to rev match. Its not really necessary since you can do it yourself, but I guess it gives you one less thing to think about.
Closer gear ratios mean the gears are "shorter". Shorter gears mean they have a higher ratio, giving better acceleration but limiting top speed. Taller gears have a lower ratio, meaning a higher top speed is possible but with slower acceleration. So if the top 3 gears are "shorter" you won't have as high of a top speed (i can't see why a begginner would even need to go above 150 anyways), but you will accelerate through the top gears faster.
Preload dampers i'm not really sure about, i'm a begginner myself. I think its an adjustable thing in the suspension. You set your pre-load to match your specific weight. Like if you're heavier than what the factory sets it at (i think most of them set it for a 150 pound person) you make the pre-load stiffer so it doesnt sag down too much, or set it stiffer if you're riding 2 up. If you're lighter than 150 you soften it up a bit.
Last edited by PTskater; 11-23-2005 at 06:43 AM.