Well, we got off to a rough start, but we are now officially in relaxation mode!
When we bought the camper it came to us in a mish-mash of tires: 2 were ST175/75R13 and 2 were ST175/75D13. The "R"'s are radial tires and the"D"'s are bias tires. The radials are better for the load we're pulling, but really there was no excuse to have 2 of each.
When the first one blew last summer we assumed it was a fluke... maybe we just drove over something. Then the other night when we got the 1st of this trip we started thinking something was wrong. We made sure leaving Rapid City that we had 4 radial tires on.
Of course the 2nd flat of our trip made us realize that something was screwes up. The salt in the wound of these flats isn't only the painin the butt and the cost of the new tire, but every time we lose a tire it does hundreds of dollars of damage that we are lucky yo have RR to fix for us.
Did some internet research and found that now days all campers of our size (21ft and loaded weight of about 5000lbs if not more) have ST205/75R14. Found out that the "ST" means it's a trailer tire so it has greater ply but thinner sidewalls. The "14" is the size of the wheel/rim. The "205" is the width of the tire in mm's, and the "75" is size of the sidewall, represented as a % of the width of the tire.
We started blaming the RV people who sold us the camper, thinking they must have thrown on any old tires they had laying around, all which were too small. This was our belief until I found the manufacturer's sticker that said that yes, the ST175/75R13 was what was supposed to be on it.
We thought about just buying the new bigger tires and wheels, but not only would that be expensive ($800), but it didn't look like there would be enough clearance in the wheel well.
We compromised by buying 4 brand new tires that are ST185/75R13, so a little wider, able to withstand heat a little better, and with a higher load rating. Overall we've gained an extra 500lbs of load carrying ability. Hopefully this is enough to precaution to get us home comfortably.
Vacation started officially last night has RR and I carted the mountain bikes 20 miles out of town and then blasted down the mountain highway. V and E clocked us at about 55 mph down some of the steeper hills!