I too was concerned, so before proceeding I crawled into the basement and there is just under a 1'x 3'x 1/4" backer plate that the approximately 1' spare tire mounting plate is through bolted to with 4 - 1/2" bolts. Since the spare tire does not rest on the bumper box when hung on mounting plate (there is a couple inch gap between the tire and the box), the addition of the bike rack actually adds back the support of the Oliver cover by resting on the bumper box. In addition, I added the two ratchet tie down straps to absorb any stress of the assembly pulling away from the camper even though I didn't detect any movement when pulling on the rack. The weight is now being carried by three points (the massive mounting plate, the rack resting on the bumper box, and the angled ratchet straps). We stay on good roads when we travel, but I will still be checking everything regularly. I will update my post after a few trips to report what I experience. Thanks, Joe/769