The more I look at these pics of bumpers, especially the one I saw with the front bumper rotted away, I'm thinking these bumpers really are to protect the clad. That rotted bumper must have been very thin-wall tube to rot like that. Hardly an adequate protection for a crash. I suspect it is there for light impact protection of the clad and the radiator. The clad will deform and possibly return to its original shape and thats what the tube bumper allows. In the rear of the VX all the pics I see show a sturdy structure where the bumper has been removed that would provide protection for the gas tank in my opinion.