My Whitehawk 23MRB is 18 months old and has less than 4000 miles I noticed today that the rear left tire is wearing badly on the outer edge. I watch tire pressure like a hawk and keep them at 50 psi. I measured distance between the tires and discovered that the left set are 1/4 closer together than the right side. Even though the tires are pretty new (build date 2015) and low miles I am considering upgrading tires. However if there is something wrong with trailer that is causing the uneven wear I want to solve it before I invest in new tires.