I haven't really looked at the two a lot in the past, just in the last couple of days. Seems to me that the WR450F is basically a yz with the 5 speed in place and lights and starter. MAIN question is if a person had the WR, could you put on different fenders, take off the kickstand, and basically motocross it? I realize it would still have the starter(a little weight). That way I could have a woods/road(occasionally)bike and motocrosser.