I just got a 08 YZ250F and I'm curious about the spring rates too. I found on race-tech website that a stock 250F is set-up for 84kg rider. I'm about 74kg with gears on so I'm wondering will it make a world of difference when I'm just 10kg short? Maybe I should just try set the sag to see how it goes first? Advice anyone? I hope this link will be useful for you http://www.racetech.com/evalving/english/Srchpr.asp?bikeid=1394&manufacture=Yamaha&model=YZ450F&year=2008&TABLEINFO=dirt&langname=english Says 08 YZ450F's ideal for 170lbs rider. You can check what's the ideal rate for your weight as well. But I guess it all comes down to what sort of riding you do and how hard you ride which plays a part too yeah?
I did a search on 'The Great Outdoors' on some torrent sites, been downloading for 3 days straight, was expecting some great motocross action but it turns out to be some Old School Movie of some folks spending their holidays outdoors?