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Old 06-10-2019, 04:51 PM   #21
Tireman9
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Wasn't this failure the type that is called a zipper failure, which is a failure of the structure of the casing. And Roger I will disagree with you your china tire view. History going back to mid 2000's with Kenda ST's, Mission ST's and so many other shows that these tires particularly on larger trailers were just not up to the task assigned to them.

When we bought a 2019 Laredo 225MK it had Goodride ST's. I told the dealer that I was going straight to the tire shop to put GY Endurance tires on it. He said run it for the first year with the Goodride's. I rejected that advice, however it shows how much confidence even this dealer had in the tires that came OEM. Chris

"Zipper" failures are fatigue failures of steel body ply sidewall. The cause for this type of failure is operating the tire while underinflated. It is not a design or manufacturing "defect".


If we look back at the tire size selected by the RV company you will see that for many, the design load capacity had zero margins (reserve load). Regular cars are designed with 15% to 30% reserve load. I do not understand why people want to blame the tires when they fail due to overloading and improper maintenance. RVSEF, the company that has weighed some 30,000 RVs has the data that shows a majority of RVs have tire and or axle in overload. It wasn't till late 2017 that RVIA required a 10% margin (still not enough IMO).


We can disagree, but I am comfortable with depending on 40 years of tire design experience and being recognized as a tire expert by the Courts.
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Old 06-10-2019, 05:20 PM   #22
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We can disagree, but I am comfortable with depending on 40 years of tire design experience and being recognized as a tire expert by the Courts.

So please explain a tire like this one failing or one mounted on the spare rack that never been on the ground. Or the guy that religiously maintained his tires, check the pressure in the morning at 15-20 minutes down the road a tire fails.

Why did GY abandon the Marathon for the new Endurance? Why has Carlisle re-engineered their radial ST tire two or three times in recent years, if it was the user that was creating the issues?
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Old 06-10-2019, 06:20 PM   #23
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So please explain a tire like this one failing or one mounted on the spare rack that never been on the ground. Or the guy that religiously maintained his tires, check the pressure in the morning at 15-20 minutes down the road a tire fails.

Why did GY abandon the Marathon for the new Endurance? Why has Carlisle re-engineered their radial ST tire two or three times in recent years, if it was the user that was creating the issues?
I told myself I would not enter into this "discussion" while the "experts" were talking again. But, here's the deal; not from a "tire expert" , one that decided to "study" tires etc. - just a guy that has dealt with exceptionally good tires, so so tires and crappy tires.

On one hand there is the premise that tires only fail due to overload, underinflation, too high speed or interply shear. Mainly due to the owner's negligence. On the other hand is the premise that there actually ARE tires made than are inferior and fail. From China? Who cares? Most are made there right? What has been pointed out in the past that many failures come from specific plants in specific provinces of China. Those are the ones to worry about.

I've said before that "china bombs" is probably a misnomer because all tires made in China are not bad - some/most areas do make good tires. But, to exonerate all those failures and put them on owners is a failure as well.

The "tire" question is relevant to every RV owner as is the validity of the company making the tire. Why do tires fail? Many reasons. Overloading, underinflation, driving too fast, poor maintenance, hitting curbs/holes - interply shear etc. I agree that those things account for the vast majority of failures, but, there is no way they eliminate poor workmanship - it exists in tires, home construction, auto manufacturing etc.....it is there and real. Every RV owner needs to do his due diligence and investigate the tires they intend to buy if Chinese. NHTSA has a very comprehensive database on many tires. On the other hand, when a thousand people tell you it "stinks like ?", "smells like "", ....I kind of go with the flow.
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Old 06-10-2019, 06:27 PM   #24
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So please explain a tire like this one failing or one mounted on the spare rack that never been on the ground. Or the guy that religiously maintained his tires, check the pressure in the morning at 15-20 minutes down the road a tire fails.

Why did GY abandon the Marathon for the new Endurance? Why has Carlisle re-engineered their radial ST tire two or three times in recent years, if it was the user that was creating the issues?

No picture, but I am pretty sure I know what you are talking about. I actually developed a laboratory test that could duplicate the condition. Long term Heat from the sun can result in degradation of the belt rubber. Proper storage would have had the tire under white cover.


Tire failure 20 min after checking inflation - Would need to see if the failure was sidewall or belt related as there are two different causes. One failure mode (leaking valve core) can be eliminated with the use of TPMS.


Tire companies are constantly revising and updating tire designs. Would you consider Cadilac introducing a new model an indication the prior year model was defective?
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Old 06-10-2019, 07:33 PM   #25
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Oh boy, a tire debate. This won’t stay active very long. I better get my two cents worth in here right away.

Right off I’m going to mention recall, or the lack of such action for ST tires. There have been all sorts of anecdotal complaints written about ST tires. There are probably numerous causes for RV trailer tire failures, even the ones causing catastrophic damages to the RV involved. So where are the recalls? I’m pretty sure that any tire forensic expert that got to investigate tires that have failed would be able to pinpoint a manufacturing cause for the failures if it was present. NHTSA isn’t in the habit of arbitrarily issuing recalls without proof of a cause.

ST tires like LT tires do not have quality grading.

OEM tires get the brunt of the complaints. The minimum standard for their fitment is to provide a load capacity that will carry the load of the RV trailer manufacturer’s vehicle certified (GAWR) axles. RV trailers are notorious for not having their weight evenly distributed to the axles carrying it. Even single wheel positions can be scary imbalanced from the factory. What have been the results? Early tire failures. What has been the established fix? Find some replacements with more load capacity. That makes the replacements the receiver better feedback from the consumer of being a better product, especially if they are not used as OEM.

In year models 2004 – 2006 numerous RV trailer manufacturers were using LT tires with a 3042# load capacity on 6000# axles. Failures were high and they bailed-out. Some of those OEM LT tires had popular name brands like Uniroyal. Goodyear then ventured into the RV trailer tire market with their Marathon. Both their USA & China made Marathon’s took a beating. Just about all Airstream trailers have had GY Marathons as OEM. They still complain about them. In my experience, the close to the bone Marathons failed. When I went up to a higher load range they did well.

I have always supported a 15% or greater load capacity reserve factor for RV trailer tires. The new recommendation for 10% from RVIA is a long overdue mandate that should reduce the ST tire early failure reporting.

IMO the majority of China tire building plants are modern well managed facilities that strive for quality in a worldwide market. One of them is building a plant in NC. I wonder what’s going to happen there. Will they produce USA, China bombs?

A 2019 dated PDF.

https://triangletireus.com/truck-tires/tr653/
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Old 06-11-2019, 05:31 AM   #26
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That is an interesting point that CW makes about OEM tires failing due to thier load rating being insufficient not the build quality. As a consumer, once the OEM tires failed they were replaced with a higher load rated tire, and subsequently the consumer experienced better results.

It will be interesting to see how OEM tires perform now that they are required to have the higher load rating from the factory.
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Old 06-11-2019, 07:04 AM   #27
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As Cal well knows we have debated the inflated weight rating of ST for many years. Now we find that even RIVA has recognized that the higher rating of ST tires could not be reliably used on RV applications and has come up with the 10% leeway glideline. In the mean time RV manufactures built to the higher ratings, and in some cases derating axles from 7K to 6750, to allow the installation of tires rated to 3420. That's right 90 pounds of excess capacity per axle.

BTW my 1996 Terry 25 foot 5th wheel had LRC Marathon tires that were still on it when I traded it in on a new trailer in 2004. These tires were most likely 9 years old at that time. The trailer was garaged when not being used.
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Old 06-11-2019, 07:49 AM   #28
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That is an interesting point that CW makes about OEM tires failing due to thier load rating being insufficient not the build quality. As a consumer, once the OEM tires failed they were replaced with a higher load rated tire, and subsequently the consumer experienced better results.

It will be interesting to see how OEM tires perform now that they are required to have the higher load rating from the factory.

First off, I want to apologize to CW and Tireman for sounding a little snarky in my previous post - I shouldn't have been (I do appreciate your thoughts and insights). I'm dealing with some issues that leave me a little agitated. Anyway I should not have logged on or worded the post differently - on to the topic.

To Logan's point about CWs observation; I too think that OEM tires have been at the overload point from the factory. The 10% margin is long overdue and still not as much as I would like to see personally. I am sure it was a cost cutting measure but don't see how it saved much money. To me it was/is more of a safety issue.

In our case my trailer has a gvw of 10k, 5k axles and came with LRD tires rated at 2540 if I recall - a tiny safety margin (no, I don't consider the tongue reduction). One big slide has all the kitchen equipment in it including the fridge. On this last blowout the tire that blew was right below the fridge, which was loaded to the gills for a 5 month trip. The trailer scale weights are fine, but, I have no way to weigh each tire and suspect the tire(s) under the kitchen side are loaded heavier than the dinette/couch side contributing to the failure. As was said, going up a load range seems to have cured that problem (hopefully).

Is the above the cause of every failure? I think not. Does a Chinese tire plant ever put out a defective tire? Of course. Is the term "china bomb" misleading and do an injustice to "Chinese" tires? Maybe.

To me just look at the brands that fail. One could say, well, that doesn't tell you anything because those brands are the ones that are used as OEM tires. Voila!! Why are they OEM? Because they are the cheapest thing the manufacturer can find. The cheapest made tire put on a trailer that will max it out right off the bat - a recipe for failure.

Now we're back to the same circle; when it fails was it due to being overloaded, cheap, defective or abused? Is a tire defective if it can't carry what it's rated for at the speed it is rated for? IMO yes. Does it pop as soon as it hits the rating on the side? It's defective IMO. If you have a chance one day I would suggest going into the tire store and have them pull a Trailer King of xxx size then pull a more popular brand like Maxxis, Carlisle etc. in the same size. Pick them up. There's your answer - extra light means extra cheap means very little durability. Defective, owner abuse/neglect/overload, cheap components? That's for each person to decide. Heck, if we all decide the same thing we won't be able to have these lively discussions.
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Old 06-11-2019, 08:15 AM   #29
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When we 1st retired & went fulltime an older seasoned fulltimer told us there are 3 things that should never be brought up in a rv park, politics, religion & favorite brand of truck, they just cause arguments.
After reading rv forums for several years I say there are 3 that shouldn't be discussed more than once, tires, hitches & favorite brand of trucks, none of them will EVER end.
I guess someone reading them might it something from them, but all I hear is BLAH, BLAH, BLAH!
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Old 06-11-2019, 12:04 PM   #30
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Tire strength to carry loads is a product of its basic casing construction. Everything added to that basic construction provides its durability. Tires of the same designated size are unfairly judged by their weight alone. Here's an example to ponder. Carlisle Radial Trail HD ST235/80R16 LRE has a tread depth of 10/32” and tire weight of 35#. The Goodyear Endurance ST235/80R16 has a tread depth of 8/32” and a tire weight of 40#. Both have a maximum load capacity of 3420# at 80 PSI. Because tread compositions are confidential we have no idea what they might weigh and why one with 8/32” may last just as long as the other with 10/32”. We do know the Endurance has built-in sidewall scuff guards. Do they account for the entire 4# excess weight above the Carlisle’s weight? Scuff guarding materials don’t add anything to the tires ability to carry its full load; treading is just something the tire casing rides on, it doesn’t provide anything to the tires basic strength to carry loads.

Steel cased tires are in their own category and should only be compared to like items. Some of them are retreadable others are regrooveable and then there are those that have both of those qualities’.
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Old 06-11-2019, 12:10 PM   #31
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Everyone is shouting BUY USA tires. Goodyear built ST tires in China that became China Bombs. China is now building ST tires in NC. What will they become?
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Old 06-11-2019, 02:04 PM   #32
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Everyone is shouting BUY USA tires. Goodyear built ST tires in China that became China Bombs. China is now building ST tires in NC. What will they become?
Better tires??
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Old 06-11-2019, 03:53 PM   #33
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I looked at this from Reddit on my iPhone and thought "Looks just like some of us from the Keystone forum (or insert your favorite forum). Tires seem to come under this area sometimes. I don't know enough about the technical end of tire building to join in that never-ending conversation, but I do know about my 'Chine-bomb Trailer Kings' and the 9K damage that Geico shelled out. Tires that were perfectly cared for, TPMS, infrared thermometer readings at every stop. And I do know about the stories from countless other members with the same ending. Chris and a number of other posters have the right idea; either tell the dealer that you won't accept those tires or bite the bullet and have new tires installed right off the lot. JMO, YMMV
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Old 06-11-2019, 04:23 PM   #34
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Loadstars are on my trailer currently. Where do they stand? Regardless they are only load range C, I don't think that's enough.
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Old 06-11-2019, 04:52 PM   #35
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OK Here is kind of my overview of tires.
1. The basic format for load capacity is Size (air volume) x PSI x K
2. The "K" is supposed to be a factor that relates to the tire service. If a tire is normally run with a 25% Reserve Load (to account for occasional low inflation or high load) on the improved highway for 3 to 5 years, you might have a high K factor like 1.1. On the other hand, if a significant portion of the population of tires will be operated under-inflated or overloaded and you want 10 years life then the k should be a lower value like maybe .80. But what happens when the vehicle design imparts excess belt stress sometimes 24% higher than seen on normal motor vehicles? The K factor should be reduced significantly. Maybe even 24% to 0.65

2. The RV industry lobbied long and hard to not upgrade the durability improvements that were placed on P and LT tires in 2002. Why? They didn't want to spend more on tires. DO they care more about their bottom line than you having no tire problems? What do you think?

3. The ST load formula was based on a MAX speed of 65 with normal highway speed of 55.
4. Given that the RV trailer travels at the same speed as the tow vehicle, why would you expect people to slow down when the strong engine can easily pull at 80 mph?
5. What is the difference between an LT tire and an ST tire today? They both travel at the same speed on the same roads. The LT only needs to last 4 to 5 years but the RV tire does not wear out till 10 years + in many cases.
6. Under what logic would you expect a tire with the letters "ST" on the sidewall to be able to carry 20% more load than a tire with the letters LT on the sidewall. The physics of Size x PSI still holds but now the operational speed of the LT and ST are the same.
7 If there were some magic rubber that allowed a company to make tires that can carry 20% more load (the difference between LT and ST) Why wouldn't the company put that "Super" compound in their premium LT tire line?

8 Only a few tire companies make ST tires. Ever wonder why? Do you think it's possible that they do not want to make tires that they can be fairly confident will not live long enough to wear out before they fatigue? Why would you make a product where a majority of the users abuse your product? Even if you do not warranty the product for more than a year it certainly doesn't make people feel confident in your brand, does it?
If I were King I would do away with ST type tires and require a 20% load margin on LT type tires in RV trailer application and require TPMS on all RVs.


But I'm not King so all I can do is offer suggestions to help people get better tire life.
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Old 06-11-2019, 05:51 PM   #36
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OK Here is kind of my overview of tires.
1. The basic format for load capacity is Size (air volume) x PSI x K
2. The "K" is supposed to be a factor that relates to the tire service. If a tire is normally run with a 25% Reserve Load (to account for occasional low inflation or high load) on the improved highway for 3 to 5 years, you might have a high K factor like 1.1. On the other hand, if a significant portion of the population of tires will be operated under-inflated or overloaded and you want 10 years life then the k should be a lower value like maybe .80. But what happens when the vehicle design imparts excess belt stress sometimes 24% higher than seen on normal motor vehicles? The K factor should be reduced significantly. Maybe even 24% to 0.65

2. The RV industry lobbied long and hard to not upgrade the durability improvements that were placed on P and LT tires in 2002. Why? They didn't want to spend more on tires. DO they care more about their bottom line than you having no tire problems? What do you think?

3. The ST load formula was based on a MAX speed of 65 with normal highway speed of 55.
4. Given that the RV trailer travels at the same speed as the tow vehicle, why would you expect people to slow down when the strong engine can easily pull at 80 mph?
5. What is the difference between an LT tire and an ST tire today? They both travel at the same speed on the same roads. The LT only needs to last 4 to 5 years but the RV tire does not wear out till 10 years + in many cases.
6. Under what logic would you expect a tire with the letters "ST" on the sidewall to be able to carry 20% more load than a tire with the letters LT on the sidewall. The physics of Size x PSI still holds but now the operational speed of the LT and ST are the same.
7 If there were some magic rubber that allowed a company to make tires that can carry 20% more load (the difference between LT and ST) Why wouldn't the company put that "Super" compound in their premium LT tire line?

8 Only a few tire companies make ST tires. Ever wonder why? Do you think it's possible that they do not want to make tires that they can be fairly confident will not live long enough to wear out before they fatigue? Why would you make a product where a majority of the users abuse your product? Even if you do not warranty the product for more than a year it certainly doesn't make people feel confident in your brand, does it?
If I were King I would do away with ST type tires and require a 20% load margin on LT type tires in RV trailer application and require TPMS on all RVs.


But I'm not King so all I can do is offer suggestions to help people get better tire life.

Good post Tireman. #4 is perplexing to me. Because the TV can pull the trailer at 65, 75, 100 mph is irrelevant. Why would we expect them to slow down? To me it's obvious; what in the world would 90% of the folks towing a 10-15k trailer at 80mph do in an emergency; right here, right now, he just pulled in front of me moment? First they would mess their pants, secondly they would try some "evasive" maneuver at 80 mph with a huge load behind them that they can't control and then.....wind up splattered along the roadside...or, mess their pants, say "honey hold on" and let the trailer drive them into some unsuspecting individual causing catastrophic damage to the driver, his/her family and the other individuals.

Anyone, IMO, that is willing to drive the speed that the tires are rated for (above 65-70mph) with a trailer behind them because they can....needs to have the trailer and their license removed - you absolutely can't control it like an unloaded car/truck.

I don't get to be King either but it is fun/enlightening to share our opinions/observations/thoughts. JMO
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Old 06-11-2019, 07:39 PM   #37
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OK Here is kind of my overview of tires.
1. The basic format for load capacity is Size (air volume) x PSI x K
2. The "K" is supposed to be a factor that relates to the tire service. If a tire is normally run with a 25% Reserve Load (to account for occasional low inflation or high load) on the improved highway for 3 to 5 years, you might have a high K factor like 1.1. On the other hand, if a significant portion of the population of tires will be operated under-inflated or overloaded and you want 10 years life then the k should be a lower value like maybe .80. But what happens when the vehicle design imparts excess belt stress sometimes 24% higher than seen on normal motor vehicles? The K factor should be reduced significantly. Maybe even 24% to 0.65

2. The RV industry lobbied long and hard to not upgrade the durability improvements that were placed on P and LT tires in 2002. Why? They didn't want to spend more on tires. DO they care more about their bottom line than you having no tire problems? What do you think? They didn't have a tire problem. They followed the standards instructions. The tire industry had the problem by allowing tires without any load capacity reserves to be used as OEM on RV trailers.

3. The ST load formula was based on a MAX speed of 65 with normal highway speed of 55. (IMO the tire manufacturer's are using a different formula. What else would explain the ST tire industry wide speed ratings going to as high as 87 MPH? Is NHTSA looking the other way?
4. Given that the RV trailer travels at the same speed as the tow vehicle, why would you expect people to slow down when the strong engine can easily pull at 80 mph?
5. What is the difference between an LT tire and an ST tire today? They both travel at the same speed on the same roads. The LT only needs to last 4 to 5 years but the RV tire does not wear out till 10 years + in many cases.
6. Under what logic would you expect a tire with the letters "ST" on the sidewall to be able to carry 20% more load than a tire with the letters LT on the sidewall. The physics of Size x PSI still holds but now the operational speed of the LT and ST are the same. (Carlisle CEO told Modern Tire in an interview that ST tires use larger & stronger cording. Do you have information that makes that untrue?)
7 If there were some magic rubber that allowed a company to make tires that can carry 20% more load (the difference between LT and ST) Why wouldn't the company put that "Super" compound in their premium LT tire line? (Just maybe the different stresses in the LT design wont permit it...The load capacity of the GY G614 RST LT235/85R16 LRG comes to mind.

8 Only a few tire companies make ST tires. Ever wonder why? (Labor Costs.)Do you think it's possible that they do not want to make tires that they can be fairly confident will not live long enough to wear out before they fatigue? Why would you make a product where a majority of the users abuse your product? Even if you do not warranty the product for more than a year it certainly doesn't make people feel confident in your brand, does it? Read the new Triangle USA ST tire warranty.)
If I were King I would do away with ST type tires and require a 20% load margin on LT type tires in RV trailer application and require TPMS on all RVs.


But I'm not King so all I can do is offer suggestions to help people get better tire life.
Most of the ST tire manufacturers are right up front with providing ST tire life expectancy.

There are numerous posts where the writer makes comments about ST tire mileage. They are not mileage tires. I've never seen ST tire warranty for mileage.

I've always said a tire's warranty is a good indicator of its manufacturers confidence in the tire's durability. Many of todays tire warranty packages - all designs - are very comprehensive and worth reading.
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Old 06-13-2019, 10:32 AM   #38
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To CWtheMan
Answering your comments/questions:
"They didn't have a tire problem. They followed the standards instructions. The tire industry had the problem by allowing tires without any load capacity reserves to be used as OEM on RV trailers."
Well CW, as you know it is the responsibility of the vehicle MFG to select the tires and to specify the necessary inflation needed to support the GAWR. The Regulations do not say "Carry the GAWR plus bit more"

===========
"(IMO the tire manufacturer's are using a different formula. What else would explain the ST tire industry-wide speed ratings going to as high as 87 MPH? Is NHTSA looking the other way?"
The formula has not changed. The proof of that can be confirmed simply by looking at the Load/Infl tables from the '70s and comparing with the current tables.
The Speed ratings were added, almost overnight, to address Federal Trade Commission, not DOT rules on tariffs on non-speed tires vs speed rated tires. Given the stated 1 year warranty some might think that since it is possible for a tire to run to a higher than 65 mph speed for a few hundred or even a couple of thousand miles some might have decided to play the odds. NHTSA simply requires tires to be capable of passing certain well-defined tests and uses the Tire Industry published Load & Inflation tables when setting the test conditions.

==========
"(Carlisle CEO told Modern Tire in an interview that ST tires use larger & stronger cording. Do you have information that makes that untrue?)" Since it is the air pressure that supports the load, not the tire structure the "strength" of the body cord is not an issue.
Body construction strength can be achieved using a number of different materials and for each material, cords are made in dozens of different configurations. Even the number of "cords per inch" can be adjusted such that fewer cords of larger or stronger material can be substituted for more cords that are smaller or not as strong. So it's entirely possible to have larger and stronger cords yet end up with a weaker sidewall. So the statement can be true but is not a requirement for ST type tires. Think for a moment of using smaller and fewer steel cords vs larger and more polyester. So which is "Better"?
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Having designed Indy type, Truck, LT, P-type and even Temporary spares I see no limit in the designs to what materials could be used. In my career, I have used and evaluated Nylon, Polyester, Steel, Rayon and Fiberglass in numerous levels of size and strength. While each may have a balance of cost vs performance that pushes the design engineer to select one combination over another. BUT as I said if just using "larger & stronger cording" somehow allowed a tire to carry 20% more load why wouldn't a company increase the load capacity of their LT tires to beat the competition?

I read the Triangle USA warranty. Sounds fine to me, so why don't we see lots of RV trailers sold with Triangle brand? I have no idea.

You may not know that Goodyear was the company that introduced the ST type tire, over the objections of other tire companies in US Tire & Rim Association according to a contact I have in the tire industry.

RE why other major tire companies don't make ST type? We can only guess but I don't see the cost of making the tires as the reason.
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Old 06-13-2019, 01:58 PM   #39
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Can you guys do this in a PM?
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Old 06-13-2019, 04:59 PM   #40
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As I said in post #29, BLAH, BLAH, BLAH!!!!!!!
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