first blowout

myredracer wrote:
I'm sure you didn't really check the pressure "about 125miles into the drive"? Needs to be set cold (in shade and after min. 2 hours of not towing on them) at ambient temp. and barometric air pressure. Getting a blowout on a single axle trailer is not a good thing...

The Coachmen 17BH is a single axle, 7' wide TT with GVWR of 3756 lbs.
Tires are Westlake ST185/80R13 - LRD with max. load capacity of 1710 lbs and max. speed rating of 75 mph.

The max. load capacity rating of the OEM tires is waaay too low. Using the GVWR, the reserve load capacity is almost zero at (3756 - 3420)/3756 = 1%. A min. of 15% is recommended and more is better. Shame on Coachmen IMO. Not uncommon for a manufacturer to do this, but this is the lowest I've heard of. We have about 30% on our Marathons and nary a problem in 4 seasons and about 20K miles.

Heat damages the internal structure of ST tires. Higher reserve load capacity means a "beefier" tire that is less susceptible to heat buildup. I think this could be one major factor in the blowout, other than a mechanical puncture.

Have you weighed the TT yet (fully loaded)? That would be a good thing to do for your records regardless. You might also check the rating of the axle too to see if it is near capacity which would make it more susceptible to damage.

The tires are speed rated 75 mph and I assume you don't tow over 75 mph. This also creates internal heat and damage.

Towing under-inflated also damages ST tires by creating internal heat. The tires should always be run at the max. sidewall psi. The exception will be if you upgrade to larger dia. tires and you need a higher psi than the rims are designed for in which case you'd need to consult load tables.

A TPMS is a great thing to have but will not prevent a blowout. You need to start by first looking at reserve load capacity. Then never exceed the speed rating, never tow under-inflated and never tow overloaded. "Curbing" tires and hitting speed bumps and potholes at high speed is also not good and need to stay off road shoulders where shrapnel can be picked up. While Westlake may have a bad reputation, all too often TT owners blame the country of origin, when it could very well be that they didn't treat the ST tires properly (they're not the same as regular automotive tires). The new Goodyear Endurance seems to be an excellent tire to upgrade to if you can make them fit.

FWIW, our first TT was a Coachmen Catalina 20RD. I used to think it wasn't very well made but after owning our current TT and seeing other TTs and reading about them, it was fairly well made. Just surprised they wouldn't put better tires on the 17BH.

maybe my original post wasn't clear. I checked the pressure before leaving (cold, hadn't moved in 2 nights), and was at the max sidewall of 65psi. The blowout occurred about 125miles into the drive. I rarely tow over 65mph (sometimes while passing) and NEVER over 70. I mostly stay in the 60-65mph range on interstates. I was going about 45 when the blowout happened. Most of that 125miles was on US-4 in Vermont and NY. It's possible I veered into the shoulder slightly and ran over some debris, as these are some pretty narrow roads, though no particular instance sticks out in my memory.

sidenote: reserve capacity is more like 9%, not 1%. still not great, but not as close to 0 as you mentioned. I'd still rather have more room than 9%.