I don't think it would be that bad really......If you take the air time you experience on a sharp drop (not a hill, but just from going from flat into a dive) It think the level of g's would be comparable to an outside banked curve. The only difference is the rider would be nearly inverted at the time when the g-forces happen. I think it would make it more intense, but not unbearable. I think the turn would have to be short and done at a reasonable speed, but I think it not realistic. I am actually still with rideman on this one....one under height/overweight/faulty restraint and the rider would be flying. No reason to create unneccesary risks when negative g's can be obtained many other ways.