ST Tire "Plies" Question and a PSI Question

Dayle1 wrote:

Tireman9 wrote:


" If ST's are designed for the unique sheer loading of trailer use, then they should be capable of surviving for more than 3-5 yrs"

The key word is "IF". Quite frankly it takes some serious effort and high power computers ($$$) to do a complete F.E. analysis. It also requires a desire to know the answer and even to conceive of the potential problem. If your primary goal is to build the lowest cost tires why would you spend tens of thousands on theoretical research.

A Google search finds only limited reference to this concept so I am not surprised if the low cost tire companies don't spend their money on this research. After all their tire warranties, if any, have a very short timeframe.

Carlisle states 3-5 yrs for their ST tires, use max PSI and don't tow over 60 mph. So are they building lowest cost ST tires? With so many ST tire failures across all brands and the industry claims about what is so different about ST tires, why do you classify F.E. analysis as "theoretical research"? Why can't ST tires be designed to both handle sheer stress and travel at speeds above 60-65 mph?

Travel above 60-65 MPH? You are missing the premise of ST tires and their inflated load ratings. To handle the higher loads, speed has to be restricted. Now if we built a better trailer tire what would it cost? Look no further than the Goodyear G614 for the answer. Or you can look at the XPS Rib and Duravis R250 for the cost of a better trailer tire rate to 3042 pounds.

Trailer manufacturers want cheap tires that carry larger loads and ST tires on paper fill that requirement. Chris