In order for a motorcycle to be balanced with the rider, spring weight, and sag must be accruate. Is it worth the $100 you'll spend on springs? You have to ask yourself this question: How serious am I about going fast safely? If a bike is undersprung it will not handle well regardless of how much compression you put into a shock/fork or how much rebound you take out. Really, $100 is a drop in the bucket if your a serious racer. Hope this helps