I agree on doing a bearing check, even if it's just jacking the trailer up and spinning the wheel ... but 50lbs psi is not "best for most boat trailer tires". My first two boat trailers had 12" wheels & the tire psi was down around 30 ... and my current boat trailer tires require 65psi. I'd have serious trouble if I simply used 50#psi as a "one size fits all" measure. :twocents