hey guys Im planning on racing a few xcs this summer. a few ixcr and a gncc or two. anyway I am a first year racer on a 400exwith afew mods. I have been riding for 3-4 years all riding being trails. so for the question, whats the difference as far as skill between C class and sport class. I know what the specs on the class are, as far as sport class is 400s and smaller 2x4, vs 450s in the C class. for a first year racer would I get over whelmed. or for my first race would I be better off in the D class. thanks for the input.