I see nothing wrong with it... Obviously the child's maturity level and comprehension play into the equation. I have no children, so no personal frame of reference, but I think a backrest/sissy bar would be a great idea, the helmet should be full face, properly fitted and snell approved, some type of reinforced clothing (leather is best), and some way of holding on securely. (koz's weight belt seems to work pretty well for his kiddo)