Well I was finally convinced, installed the XR springs today. They were $52.95 each CDN vs $67.95 each for Kawasaki springs, that helped the decision. With a measured distance between the top of the installed spring and the bottom of the fork cap, installed on the extended rod, of 3mm, I ended up needing a piece PVC pipe exactly 10mm for a 10mm preload. ( 10mm pipe + 3mm of spacer guides ) Just lucky I guess. I now have an unloaded sag of 1.25" and a loaded sag of 2.5". I think this is in the right ballpark. Question is does anyone know the relationship between preload & sag ? i.e. how much would an increase of 2mm of preload on the springs lessen the unloaded sag ?