I am no tire expert by any means but was told this second hand info, so take it for what its worth. lol
A guy bought a trailer second hand and it had been barely used maybe 4 years old. He took it on a 300 mile round trip to haul some propane tanks ends up blowing 6 new tires that came with the trailer, the two that didn't blow had already been replaced. Tire sales man told him there is a active ingredient in the rubber that if not used will cause tire to break down the cord and come apart.

I hope he had his hip wader on as it sounded pretty deep with BS.

Yea....... 99.9% of the time ST tires fail from heat build up caused by low pressure. If you want to read about tires look here: http://media.wiley.com/product_data/excerpt/19/04713546/0471354619.pdf

Most tire failures are because people tow at excessive speeds. There is very few ST tires that are rated for over 65 MPH. Like with my trailers (utility and RV) I never tow faster than 55-60 MPH and never had a tire issue. I know both trailers have tires rated for MAX speed of 65 MPH. But how long do you expect a tire to last right at RED LINE? Just like saying your going to run your engine at red line and not expect it to throw parts.

 

Second problem is over loading the ST tire with too much weight.

 

Third problem is under-inflating a ST tire.

Most tire failures are because people tow at excessive speeds. There is very few ST tires that are rated for over 65 MPH. Like with my trailers (utility and RV) I never tow faster than 55-60 MPH and never had a tire issue. I know both trailers have tires rated for MAX speed of 65 MPH. But how long do you expect a tire to last right at RED LINE? Just like saying your going to run your engine at red line and not expect it to throw parts.

 

Second problem is over loading the ST tire with too much weight.

 

Third problem is under-inflating a ST tire.

I don't quite agree with you on the underinflation being after the overload. Most RV trailers are not overloaded far as tire capacity and a lot don't run over 65 mph. I used to pull drop deck trailers (when I drove big trucks) and one company had two spares on each trailer because they blew so often and when I went to another company they had no spares on the trailers. I asked why and they said they ran 115 psi in them instead of the 95 psi recomended. They were right, there were very few tire problems with them.

You might want to peek over the RV sites. It will surprise how many people over load a RV and wonder why the tires are popping like popcorn. Most RV owners tend to inflate to max on the side wall. Common out here to see utility trailers over loaded with firewood and tires blown out.

 

Industrial trailers a bit different than a smaller Load Range C or D tire on a utility trailer. Kind of like my utility trailer Load Range C's rated for 50 PSI I typically run 40 PSI. Because I've never gotten to squeeze the tires down flat faced much. Even with full loads of firewood. But still no tire failures.

 

Or like my RV with Load Range D's inflated to 65 PSI. But I know the scaled weight of 8,020#.

 

But still in all you should run within the designed limits of the tire for longevity.

I am registered on a couple of RV sites. You forget I also have a fiver too. I found that if I run the tires at 70 psi instead of 65 psi the do run cooler. I really don't believe that all those RVs are running overweight. The weight police on those forums are brutal.

Weight police.

 

No I'm meant the people with tire failures. When you ask if they scaled ever most will answer "No." then when they do scale the trailer axle weight is typically over the tire capacity. But yeah I know the weight police you talk about too that scream about GVWR capacities. I'm speaking about tire capacities at stated pressure.

 

I remember ISX sayin something about wheel and tire testing in a pass thread too... I wish I could find it.

Just a side note to keep in mind, if people are running the tires over weight, the running gear on the trailer (axles, hubs, bearings, etc) are more than likely also overweight. If the trailer is set up properly, the weight capacity of the tires should always be higher than the full capacity of the trailer. Out of all the trailer tires I have sold, it has come out to about 50/50 between under-inflation and excessive speeds. I dont think either issue is more common than the other one.

 

If someone wants to be running upwards of 65-70 mph with their trailer, at the very least they need to be running radial tires that are rated for the correct weight. ST trailer tires are still a biased ply tire. Not good for high speeds.

 

This is just based on my personal sales experience in light trailer parts.

My Maxxis 8008 tires are ST and they are radials??? The ones I had on before were radials too......... http://www.maxxis.com/catalog/tire-122-129-st-radial-m8008

My bad. I just meant the ST tires that we stock and sell are biased tires. I forget that radial ST's are out there. Just curious, do you know what the speed rating is on those?

I've also got radial ST tires on both trailers but neither tire is rated for above 65 MPH period. Maxxon and TowMax are the brands I'm running currently.

I have not ever seen any ST tires that are rated over 65 mph.

I've got 1 set of ST tires that where rated for 99 MPH. I actually ran them on the truck. Speed rating of a Q. Load Range G. Size 235/ 85 R16. So they do exist but not common place. What's funny is this set of tires where China made and worked wonderful on the truck for 30k miles which was typical tire life for me.

 

https://www.bigotires.com/Tire-Detail/VOMA/SOLID-TRAC-RADIAL-A-S-TRAILER/23024

 

I've got 1 set of ST tires that where rated for 99 MPH. I actually ran them on the truck. Speed rating of a Q. Load Range G. Size 235/ 85 R16. So they do exist but not common place. What's funny is this set of tires where China made and worked wonderful on the truck for 30k miles which was typical tire life for me.

 

https://www.bigotires.com/Tire-Detail/VOMA/SOLID-TRAC-RADIAL-A-S-TRAILER/23024

 

Screenshot from 2014-12-08 11:21:33.png

 

That is a trailer tire for sure, but I don't see the ST designation.

 

I am fairly confident that the ST designation is limited to a 65 mph rating.

 

The only tire I know of that is ST and allows operation above 65, but isn't "rated", is the Goodyear Marathon.

 

https://www.tirerack.com/images/tires/goodyear/Marathon_Special_Trailer_Applications.pdf

 

I have had great luck with Marathons over the last 6 years of owning TT's. I have had 3 flats and they were ALL from nasty dirt roads and sharp punctures. I have towed at 70 for many miles and never had a blowout, but I always run a lot more air than needed and don't get much above 80% of the weight rating. 

 

I will be getting new tires this year and will step up to 16" rims and a LRE LT tire. I am looking for more puncture resistance than ST tires offer.

I've still got the tires in the yard I pop a pic of them.