Preload adjusts the ride height, sag and the operating range of the suspension. Only thing that softens or stiffens the spring is fitting a softer or stiffer spring.
Absolutely. If you are trying to make a soft spring still or a stiff spring soft, you’re out of luck, as you need a spring appropriate for your weight. If you are dialing in your suspension you can affect the ride quality a fair bit by backing off or screwing in the preload. I know this because I’ve been experimenting with this process on my bike and my brothers bike. My advice for people suffering from a harsh ride is to first set up your sag settings properly, then experiment with more or less sag. Believe me, when I had my bike set up at 30mm of sag front and back, that was a much firmer ride. We experienced the same results on my brothers GSXS-1000.
