Bought a new tandem open trailer in April. For the first couple of months I was running a straight trailer hitch which had the trailer not running as flat as it should be (but it did keep the mower deck from scraping coming off the trailer). Then I put on a 4" drop hitch, which made the trailer run level, but I barely could get the removable trailer jack wheel on and off. Now I have a 2" drop to avoid that problem. Anyway, between the trailer not running perfectly flat and all the turning around we do in cul-de-sacs on our route the back tires are already bald. The original tires are cheap TaskMaster, I think. What would be a good hard rubber longer lasting tire to replace these with?