alot of them are interchangeable, my mr was missing the seat and wouldnt go into gear and the top end wasnt the best...so now i have an mrz50r :laugh:i will be posting a build thread on it some time in the near future, i am not sure on a crf though, the forks would prolly bolt right on, they did on the z50...i had to drill new holes for the swingarm though.