I'm planning to install a bike rack on the extended pin box of my Rockwood 5th wheel. Seems this would be a good place rather than hanging them off the rear bumper. When I had my TT, I carried the bikes in the truck bed, so didn't need a bike rack.
Anyway, I was surfing the web for "pin box mounted bike rack" and came across this
. The owner/builder did a good job at posting a detailed set of photos.
Just thought some of you 5th wheel owners may be interested in this type of bike rack.