jcarlyle wrote:

Whatever you choose, make SURE that it is an ST tire - this stands for
Special Trailer. And DO NOT run them at low pressure - run them at
whatever the pressure is that is stamped on the sidewall to get
maximum load carrying ability with minimum heat build up.

Be aware ST tires have a 60 mph speed rating at the standard pressures.
You can raise the rating to 70 mph if you inflate to required pressure
for this higher speed.


As for the radial/bias question, radial tires are *not* recommended
when lateral sway is a problem.

Cobra delivers all their trailers with radials. Go to the RV dealers and
look at all travel trailers and 5th wheel trailers, and you will find
out they are all riding on radials. That's because radial tires are far
better tires, even for trailers. The bias ply tire's only advantage is
it's a few dollars cheaper.

If you compare a passenger car radial to a bias ply ST trailer tire, you
might be right.

However, radials do run cooler, and
they provide a softer ride.

And they are more road hazard resistant.

I'm leaving this Friday to pick up a glider that I purchased 1100
miles away. The trailer looks brand new, but is about 12 years old,
as are its tires. The glider and trailer weigh in the vicinity of 950
#.

What is in it? It is worth weighing it if you are at all suspicious
about the claimed weight.

Assuming the 950 pounds is right... Unless you are towing this with a
Volkswagen Beetle, it seems unlikely such a light trailer will cause any
problems, regardless of the tires.

The tire spec from the owner is :
Carlisle Sure Trail ST
ST205/75014 (replaces F78-14ST)
Max Load 1760 lbs @ 50 PSI (actual load will be under 500 lbs)

The ST inflation chart show a load rating of 850 pounds at 15 psi! This
tire is serious overkill for the weight of your trailer. Even the
smaller ST175/R13 has a 670 pound rating at 15 psi.

If it were my trailer, I'd just put on passenger car tires with a speed
rating about 20 mph higher than I planned to tow, and a 1000 or so pound
load rating, then use the correct pressure for a 600-700 pound load.

--
Eric Greenwell - Washington State, USA
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