Originally Posted by pgandw
It was me. Printed on the sidewall (among other warnings and ply makeup) of my 2014 Rockwood A122 OEM tires:
ST185/80R13 Load Range D
max load single axle 1710 lbs at 65 PSI
max load dual axle 1520 lbs at 65 PSI
I was surprised when I read all the fine print on the sidewall. I was also surprised that I could not find another brand of same size trailer tire in load range D on-line at any of the popular sites.
2014 Rockwood A122 A-frame
The de-rate refers to the tire not the number of axles and therefore the combined weight capacity increases significantly with 4 tires. I think it has to do with a flat tire and 3 tire capacity remaining with only 1 on one side (a safety factor) JMO