Swagman model 80550 is designed to fit on the roof of pop-up campers,it will hold four bicycles.I would check with your trailer dealer to verify the roof will support the load.Model 80500 is designed to bolt onto the rear bumper of the trailer,it holds two bikes.I would think that putting the lightest bikes on the bumper rack would be the best in terms of balance for the trailer toungue weight,even a small amount of weight that far back may make a difference.I have no personal experience with either design,but they seem like they might solve your problem

Swagman model 80550 is designed to fit on the roof of pop-up campers, it will hold four bicycles. I would check with your trailer dealer to verify the roof will support the load. Model 80500 is designed to bolt onto the rear bumper of the trailer, it holds two bikes. I would think that putting the lightest bikes on the bumper rack would be the best in terms of balance for the trailer toungue weight, even a small amount of weight that far back may make a difference. I have no personal experience with either design, but they seem like they might solve your problem