I am interested in getting the YZF450 but am skeptical about the 4 speed of the older models (05 and previous). I was wondering what your thoughts were on these. I talked to a buddy who use to have an 04 and he said he was changing sprockets like crazy for each track and he didn't like it to much for motocross. I plan on riding motocross tracks mostly. How does it compare to the CRF450 5-speed transmission. Thanks in advanced.