The China-Bomb debate Put to rest
Almost every week or more a thread appears with someone with a tire question. And just as predictably the China Bomb experts come out and start decrying all Chinese made tires. Then usually they re...
Forum Discussion
Let's separate some facts and fiction regarding ST vs LT tires. Specifically the claim that ST tires are not made to be as strong or as robust as LT's.
Here is an excerpt from a Trailer Life article from June of 2013:
ST VS. LT
What is a trailer tire and how is it different from a light truck tire? Most trailer tires are specifically designated “ST” because as Special Trailer tires they are designed to handle stresses that are not common to “LT” or light truck tires.
You may have noticed that tight turns with your tandem- and triple-axle trailer put tremendous side loads on the tires. You can see it in the sidewalls or hear it coming from the contact patch. ST tires are designed to handle these side stresses; LTs usually are not.
ST tires are also specifically designed to resist movement that can cause trailer sway, which can be a tremendous advantage in trailer handling.
According to some ST tire manufacturers, the polyester cords used in ST tires are bigger than those found in a comparable P-metric or LT tire. For the most part, the size of these components is directly relative to the tire’s size and load rating regardless of the tire’s type, be it ST, LT or P-metric, and the components are correctly sized for a given tire.
ST tire compounds contain chemicals to resist weather and ozone cracking, which are conditions that trailer tires often endure during long-term storage. Characteristics
of these tire compounds also address the inconsistent duty cycles of trailer tires that go from extended inactivity to hard use.
Use of non-ST tires should only be done at the recommendation of the trailer manufacturer. There is no shortage of “experts” online who will swear that ST tires are a conspiracy and that LT tires are better for trailering, but problems with ST trailer tires are likely to stem from not properly maintaining tires, running them underinflated, speeding or a plethora of other trailer-tire mishandlings. We are going to go with the recommendations of the trailer makers and the tire industry.
Now here is what Carlisle Industries has to say about the issue:
THE ST DIFFERENCE
The construction, design, materials and testing used in ST Special
Trailer tires meet the higher load requirements, duty cycles and
special demands of trailering.
– Polyester cords in an ST tire are bigger than in a comparable P or
LT tire.
– Steel cords used in ST tires have a larger diameter and greater
tensile strength to meet additional load requirements.
– ST tire rubber compounds contain chemicals to resist weather and
ozone cracking, particularly conditions resulting from extended
storage and the unusual duty cycles of trailer tires.
– The slightly shallower tread depth of a trailer tire reduces sway and
rides cooler, which adds to tire longevity.
– ST tires feature stiffer sidewalls, especially in the lower
section which:
– Reduces sidewall flexing causing the trailer to track straighter.
– Diminishes the risk of trailer sway.
– Lessens the risk of sidewall puncture and blowout.
– ST tires generally offer approximately 10% percent more load
capacity than a similar LT tire and nearly 40% more than a P
passenger tire.
I Find it interesting that while I present facts from independent and industry sources those who claim to have "Real World Data and those who continue to poo poo this NEVER do the same.
Here is an excerpt from a Trailer Life article from June of 2013:
ST VS. LT
What is a trailer tire and how is it different from a light truck tire? Most trailer tires are specifically designated “ST” because as Special Trailer tires they are designed to handle stresses that are not common to “LT” or light truck tires.
You may have noticed that tight turns with your tandem- and triple-axle trailer put tremendous side loads on the tires. You can see it in the sidewalls or hear it coming from the contact patch. ST tires are designed to handle these side stresses; LTs usually are not.
ST tires are also specifically designed to resist movement that can cause trailer sway, which can be a tremendous advantage in trailer handling.
According to some ST tire manufacturers, the polyester cords used in ST tires are bigger than those found in a comparable P-metric or LT tire. For the most part, the size of these components is directly relative to the tire’s size and load rating regardless of the tire’s type, be it ST, LT or P-metric, and the components are correctly sized for a given tire.
ST tire compounds contain chemicals to resist weather and ozone cracking, which are conditions that trailer tires often endure during long-term storage. Characteristics
of these tire compounds also address the inconsistent duty cycles of trailer tires that go from extended inactivity to hard use.
Use of non-ST tires should only be done at the recommendation of the trailer manufacturer. There is no shortage of “experts” online who will swear that ST tires are a conspiracy and that LT tires are better for trailering, but problems with ST trailer tires are likely to stem from not properly maintaining tires, running them underinflated, speeding or a plethora of other trailer-tire mishandlings. We are going to go with the recommendations of the trailer makers and the tire industry.
Now here is what Carlisle Industries has to say about the issue:
THE ST DIFFERENCE
The construction, design, materials and testing used in ST Special
Trailer tires meet the higher load requirements, duty cycles and
special demands of trailering.
– Polyester cords in an ST tire are bigger than in a comparable P or
LT tire.
– Steel cords used in ST tires have a larger diameter and greater
tensile strength to meet additional load requirements.
– ST tire rubber compounds contain chemicals to resist weather and
ozone cracking, particularly conditions resulting from extended
storage and the unusual duty cycles of trailer tires.
– The slightly shallower tread depth of a trailer tire reduces sway and
rides cooler, which adds to tire longevity.
– ST tires feature stiffer sidewalls, especially in the lower
section which:
– Reduces sidewall flexing causing the trailer to track straighter.
– Diminishes the risk of trailer sway.
– Lessens the risk of sidewall puncture and blowout.
– ST tires generally offer approximately 10% percent more load
capacity than a similar LT tire and nearly 40% more than a P
passenger tire.
I Find it interesting that while I present facts from independent and industry sources those who claim to have "Real World Data and those who continue to poo poo this NEVER do the same.
