[zachiatrist]

Speaking from experience in this matter.. a simple pipe notch will be plenty but someone above was right, you'll smack the pumpkin into the bed before the frame. Before I had bags, I had drop springs and 2" lowering blocks in the back and always hauled my Harley around no problem, which is much heavier than your dirt bike. I also have CPP c-notches installed, but you gotta cut a hole in your bed for the pumpkin before the axels will go very far up into the notches.. the hole was never needed with a spring setup... and I've hit some gnarly ass pot holes and dips with my Harley in the back and never spanked the bottom of the bed that I can recall. So all in all, you should be fine and dandy.