I have one of these bikes and race a lot of harescrambles. I am thinking of purchasing a 05 WR. Or am I better off setting the 450F up for harescrambles? I know the bike with the 4 speed in it is a little too much. I have added a 10 ounce Zip Ty Weight. What other things can I do to make it better. I am a A-AA Rider? Any suggestions would be great. What is the better bike?