I MX ride and had my rear shock revalved twice but it was still bottoming out on hard landings. I thought I'd have to look at the spring rates. I wanted a Zero Preload Setup so after much research I tried a slightly stiffer progressive rate main spring from KTM dirt bikes(2003 KTM 250SX) and it works like a champ. There is very little preload but great progressive suspension action...really! Check out factory connections website for different rates. The stock main spring is a straight rate at about 6.6kg/mm. The PDS-7 off of the KTM shock is progressive from 7.5kg/mm to 9.5kg/mm. This allows less preload and greater use of the tender spring along with a higher bottoming resistance...plus these springs are a dime a dozen as alot of guys change them out. Try it, you'll like it!