[Andy Friar]

Wheel dia is just one factor to check/ consider, but pretty low on the list IMO. Loading and weight balance. Bent axles and/or out of alignment to each other and causing tire scrub. Not enough air in them when the trailer is fully loaded is another heat generator that causes tire delamination and thus failure. Bent rims can causing heat build up or leaking rims due to corrosion/rust at the tire bead can happen too. Good tires are another key factor. Both weight rating and brand. Had best luck w/ Goodyears on race trailers and commonly used on test trailers at the various OE proving grounds around here in Michigan. Just my $.02