The bolt on spare tire holders are off set to clear the frame. On a straight tongue like a boat trailer they work great since they can be mounted away from your hitch . On an A-frame tongue like a camper or utility trailer they over hang the frame 6-8" or more and it can be near your hitch or coupler. If you need to make a tight turn while backing you can pinch the tire between the trailer frame and your bumper and bend your bumper. Don't ask me how I know it will happen.

Eddie