I can't comment on your specific motor home or motorcycle, but I have loaded a Gold Wing in a pull behind Toy Hauler. If the ramp was too steep the transition at the top would cause the bike to bottom out.
I put wooden blocks under the ramp to lift it about four inches and built a small double thick plywood ramp to get onto the Toy Hauler ramp. That helped with the inclination of the big ramp.
Backing down the ramp is no problem if you leave the bike in gear and release the clutch to slow or stop the backward motion.
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