What I have gotten out of your reactions is next.
GVWR 7700 lbs.
2 axles 4 tires on the road when driving.
Now having ST ( special trailer) tires with C-load ( maxloadpressure 50 psi)
14 inch rimms.
Probably weightdifference R/L because of the slide on one side.
What I am missing are the exact sises of the tire and the loadindex or maximum load. When you give those , I can put it in my chanced calculator that can be found in the map.
So you can also play with it yourselves.
I included the tow-barr weight in the pressurecalculation now , so if you take another towbarr weight the needed pressure is also chanching now.
But now the beginning Bumping and Damage border are the same .
Can make a picture of it again and place it here as example.
The ST tires are calculated in their maximum load , for a lower speed , so the tire may deflect more before it gets damaged , and that gives a higher maximum load then a normal road tire or LT with the same sises.
This brings them more to the edges of possible Damage.
By putting from the beginning at an still undamaged tire, the 10 psi extra, wich is supported by the TRA for higher speed then 65m/h, the deflection gets less and so tire-damage does not appear that soon.
But I thougt there where enaugh LT tires in 14 inch , example 185R14 with D-load so 65 psi and loadindex 102 so 850kg/1874lbs times 4 makes 7500 lbs.
Must be enaugh if you substract the tongeweight of 10%.
And then even you could add the 10 psi for extra savety .