Thanks guys. The tires were old. In the morning, the left one was flat. I pumped it up to 40 psi, made sure the other side was the same, and set off. Fine going to the marina, about 80 miles. About 30 miles from home on the return, or about 130 miles total, I got a sudden, harsh vibration, move to the breakdown lane, and found the tire had disintegrated, about 60% of the tread just gone, with enough rubber remaining on the wheel so the wheel wasn't damaged.
It's a light weight, single axel dingy-sailer trailer, and I was carrying my 9.5' AB rib with 15HP Merc, plus 3 60 lb. boat batteries in the rib.
I left my lovely wife with the boat and ran to Bass Pro Shops, which was 11 miles away, and bought two new wheel and tire assemblies, same size as original, five bolt, galvanized, with 4.8x4 tires. I also had to stop at NAPA and buy a lug nut wrench, as the Honda wrench was too small.
Thank goodness I had previously applied anti-seize to the lug bolt threads! Even so, they were tough to remove. Two were tougher to replace; at first I thought they were cross-threaded, but no, just corrosion and crud.
I was thinking I'd replace both wheels on the side of the highway, but my wife thought we should just replace the blown one and get out of there. I think she was right. Ride home was uneventful.
I had replaced the right side wheel bearing last year. The left runs smoothly and quietly, but hasn't been greased since I don't know when. No Bearing Buddies on these. So, I should at least grease it, maybe just install a new bearing.
I'm curious, too about the lug bolts. My hubs use bolts, not studs with nuts. The wheel holes are dimpled, but "dimpled out," if you know what I mean, which is counter intuitive for me.
BTW, wheels with tires were $64.99 each at Bass Pro, and an 'industrial strength' lug nut spinner was $27 at NAPA. I'm not complaining, at all, given the circumstances. From blown tire to back on the road was about one hour.
