I have had two airstreams (1976 29' and 1997 25'). I have used Goodyear ST Marathons in 225x75x15 on both and have had excellent luck with them. I tow about 10 to 15 thousand miles per year.

What I have done with wheel bearings is to pack them at about 6 months after the initial purchase and every other year after that. Each time I've pulled them apart they have had plenty of grease an the bearing were fine. I also use that same schedule to check brakes and have found that adequate as well. I replace the shoes if they appear to have less than 50% of the lining left. As I tow with a Cummins powered Dodge PU with an exhaust break lining last a very long time.

I will enjoy reading of other's experience.

Jerry in Oregon