cweimaraner:I have a crotch strap installed on my jetharness. The problem seemed to be me wearing my weight belt on the outside of the crotch strap. I put on my weight belt then the jetharness and all seems well. I think it was just pushing the whole assembly up on my back and hence hitting the back of my head. Problem solved.
Jim
If I understand your current setup with the crotch strap it seems like it would be difficult to ditch the weight belt - unless you have ditchable weight pockets on your belt. I am planning to add a crotch strap to my Jet Harness but hadn't really thought of this possible complication.
Chuck