Used Trailer Rims How Do I Find The Load Bearing On Rims?

How do I find the load bearing on rims? - used trailer rims

I 6x10 open utility trailer home with 12 "tires. The GWC? Is 1500 pounds.
"There is enough room for larger tires to be used. I am interested in the use of 14 to 16" 4-LUG used tires. The tires, which I have not found a Hyundai, VW and Ford Focus, a racing game are the wheels Eko.
* How do I know if I lose weight I can carry the load?
* What will change (except for the appearance and size, the target) with a larger tire? This effect is the travel trailer and negative?
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The trailer is really quite a Chopper HD 650 pounds. Not much more than a ramp and tool box.