It also depends on the rack you have.
if you can get the bikes on the tongue it will work better but on my new trailer there is barely room for the tanks and battery.
When I bought the trailer we needed to put the bikes on the back but I didn't trust the bumper so we cut it off, welded a 20" rack with angled bracing that welded right to the frame, welded the bumper back on( People think its factory
), placed an alum. tool box on 1 side, then I made a 2" hitch that sat up above the rack and used a standard bike rack like this one.
things went fine for the first trips but then the rack it self failed and my bike fell down and back between the trailer and hitch (first dents are always the hardest) and the movement was so violent that the other 3 bikes almost came off and my sons bell just exploded.
Since then I added 1 stiffener to the hitch system (not sure I needed it but had the metal and time) and I bought a bike rack like this
and believe my it is worth the money the bikes are solid.
I did take the spare tire off and I just put it under the bed for long trips I will put a second in the truck.
I'll try and take pictures this weekend while camping