The spring rate also has to take in effect Swingarm angle, front bias, Rake and trail. Where one bike a 450 could support 200 lbs on another bike with different Geometry 450 would only support 150 (example only). I know the 01-05 the GSXRs for track you would raise the front end 5mm or so but raise the rear 10mm at a min. 06-07 and 08 more then likely to get ideal settings they are raising the front 5+ (as much as stock would allow, and some put fork extenders so they could raise it more) and only raising the rear 2-3 or less. My 06 1k race feels like the front end is higher then the rear, but still handles good.