Just bought a 2010 yz450f. I'm a 230lb vet expert, mx only racer. I rode it once and thought it was good, but I need to change the springs for my weight and height (6'3"). I'm thinking of going with 0.5 for the front fork springs and a 6.3 on the rear. The yamaha manual does not even list springs this high. I will revalve it after testing with the proper springs. Anyone have any experience with this setup and what did you do for your revalve. I'm an automotive engineer with a chassis background, so a good starting point will help me out greatly.