Here's an idea that you might give a try. Go to your local speed or muffler shop. Ask for a product called header wrap. This is used to wrap around the pipes to insulate it from surrounding areas. Since the heat shield on the pipe covers most of the header pipe anyway, then this should not be an eyesore. Just remove the heat shield and wrap the pipe everywhere except the area where the heat shield clamps go. If this does not work or you need more shielding, then try mounting an aluminum shield to the frame bolts between the pipe and bars. Just be sure the alum shield does not come in direct contact with the pipe or the heat will transfer to it also and cause the same problem as before.

Stan