Years ago when I was a kid fresh outta the army, and working my way through auto mechanic college (Johnson College), at Sears, they had a guy come in to give us all a class on tires.
THEN, we were told, a radial tire has wires, (cords sets) that will "move" in the direction of the rotation when the tire heats up, NEVER cross roatate the tires as they (the cords) will start to move and buckle.
Firestone had a problem back then with the 721? tire, that the cords buckle up and wiping out the tires, (I did a lot of recall tires when I was a working wrench for Chrysler after grad-E-tatiing).
(I had "borrowed" a set for my Dodge Powerwagon I had at the time, and blew the fronts on the interstate one fine day)
Bias ply was OK, but not radial.
Now flash forward 32!!!! years and tires design have changed, alot.
Radial CAN be cross switched with little or no problem, (my son just grad-E-Tated from the same school, weird for me!!), he had a tire class whilist there and was told that.
That all being said, I still don't cross rotate my radial tires on my trailer(s).
I've been hauling motorcycles to races all over God's green earth since '75 when I got my license, (well short of the 3 years I was in the "green weenie").
There were some years I'd put 40,000 miles on my trailer and van, ("Hotel Dodge")
I've never had a set of trailer wear out, blown out, yes, dry rotted yes alot, but worn to the skins, never.
If your wearing tires out, your axle is outta alignment, spindle bent, etc.
Best thing is tire PSI keep them up to what ever they call for, pack the bearing each year (Always new grease seals when you do them, (I give my "Grease Buddies" a few shot EACH time I dip my tires in the H2O.
Joe
1, Take any advice given with a beer and
2, Remember some people said the stock market could never crash, the Titanic was unsinkable!