Hi Echo -
Good, intelligent question. While not an RV owner yet, one the scenarios I had envisioned was a hitch platform for a 300# scooter. And I could see I needed to explore chassis load dynamics.
Weight hung off the back obviously affects loading dynamics, as that rear axle centerline acts as a fulcrum, multiplying the load beyond mere pounds.
The first issue is making sure the platform itself and the bikes together do not exceed the 500# rating of the receiver.
Then you apply a formula to determine axle load changes. There was a really great primer on this somewhere out on the web by a recognizable authority, but can't remember where it was. But did find this civillian example quickly on another Board. Hope this is accurate, because I can't find that more authoritative table right now.
Suffice it to say there is a better authority out there, but here's an example I found easily:
"The formulas are:
FrontAxleUnload = Load x (RearAxleToLoadDistance)/Wheelbase
RearAxleLoad=Load + FrontAxleUnload
Example:
The wheelbase of my camper is 160". I hang a 200 lb total load on a
platform about 120" from the rear axle.
FrontAxleUnload = 200lb x 120"/160" = 150lb
RearAxleLoad = 200lb + 150lb = 350lb"
Food for thought
