Adding bikes to bumper

Roughly 75 lbs. for the 2 propane tanks full (assuming they are the “20lb” variety) and about 50 lbs. for the battery.  So 125 lbs. for the whole package up front.  If your 4 bikes each weigh 32 lbs. a piece, including the weight of the bike hitch, it's even.  So you may be in the neighborhood.  I would find out the precise weights of all the gear you are adding to the front and the back so you won't create an unstable situation.  Then weigh your trailer then measure your tongue weight.  The latter should be about 10% of the total weight of the trailer, fully loaded.  Also note that as you use propane your front end will get lighter.  (Also consider other variable weight items on board, like fresh water tank and black tank if you have them.)  FYI, A trailer heavy in the rear allows lots of tendency for trailer sway.  Heavy in the front, and your tow vehicle gets very light in the front end and makes stability in wet weather questionable.  Weight distributor/anti-sway hardware helps a lot even when your trailer is balanced.  Balance is a good thing  .