China Bombs Got Me

mike mck wrote:

wandering1 wrote:
If you have facts about what caused the tire failures I am sure the DOT would like to know. All tires have to meet DOT standards regardless of where they are made. Amnerican made trailer tires blowout just as much as foreign made tires.
If you don't know what caused the failure don't waste your time and everyone elses complaining about blowouts.

Interesting comment. Where did you find the statistics of American tires blow out just as often as Foreign tires? Now this is just my opinion but I think the discussion is not all foreign tires but tires made in China.

workhardplayharder wrote:
Good tires aren't cheap and cheap aren't good.

wandering1 wrote:
If you have facts about what caused the tire failures I am sure the DOT would like to know. All tires have to meet DOT standards regardless of where they are made. Amnerican made trailer tires blowout just as much as foreign made tires.
If you don't know what caused the failure don't waste your time and everyone elses complaining about blowouts.

JJBIRISH wrote:
......Here we agree again and an example of exactly that was, what you don’t know can kill you when it comes to your tires… as the American importers of Westlake LT tires Foreign Tire Sales found out a few years ago, when mfg. Hangzhou Zhongce Rubber Company of China decided to intentionally leave out critical parts of the tire and cheat on testing to fraudulently DOT certify Westlake, Telluride, Compass and YKS tires......

CapriRacer wrote:
JJBirish,

Thanks for the reply. Do not trouble yourself about the slow response. This was a holiday weekend and I would expect that RV'ers would be enjoying their RV - and that would probably mean being out of electronic contact. Besides, the important thing is getting to an understanding what is going on. A better understanding would lead to a better strategy to solve the problem.

My internet problems are just beginning now I am back to my home base for the summer…
Verizon sucks but the others are non-existent… I need to go somewhere with Wi-Fi to do anything…


Again, while I would like to comment on several items, but I am going to focus on this:

JJBIRISH wrote:
....As far as you assertion that the ST could pass some of the test… maybe… But I doubt the ST tire would pass that test either… sure it would only be 110% of its rated load for that psi but it would also be at 10 MPH above its maximum rated speed…......

I'm taking this to mean that you think that speed is an important parameter and at the very least of equal importance to the load. Maybe more important?

I think speed is an important parameter and is the reason for having speed ratings… this is especially true on radial tires built without the full cap, that many ST tires are built without…


Does this also mean that it may be unfair to test a tire above its rated speed? (unless it is compensated for)

I do not think it is unfair for the sake of testing to test a tire above its rated speed or load…



And lastly, I was right. We have a difference of opinion about DOT testing and how tires would perform on these tests. That difference is reflected in our different approaches to the subject.

I'm approaching this from the point of view of tire engineering and how tires have performed on DOT tests in the past compared to how they perform in real life. I have experience in this area and some of the things you've asserted are not accurate. It is pretty well understood that in order for a tire to perform adequately in real life ("adequately" being a moving target), it has to pass the DOT tests by a considerable margin - much more than the minimum - and tire manufacturers have a system to monitor tire performance - the Adjustment System.

I am aware of and respect your expertise in the field, and I am just some blue collar Joe whose work shirt has his name on it… I spent a lot of time researching the ST tire issue, mostly because it took a lot of time just to follow and decipher the testing process… admittedly in my untrained mind I may not be able to properly articulate some of the things I believe and there may be things I just didn’t understand, but I think I have a good grasp on the problems and the causes… although I am much more skeptical about the manufactures intentions than you are… while there was a time tire companies earned loyalty by building a better product I don’t believe in this economy and this business environment that is so much of a priority any more…

Every tire manufacturer has a system where tires that do not perform up to the warranty are to be adjusted by the dealer (money exchanges hands between the consumer and the dealer), then the tire is sent to the manufacturer where it is examined (and money exchanges hands between the manufacturer and the dealer). So the dealer has an incentive to capture failed tires and present them to the manufacturer. The manufacturer, then, is required by law to show this data to the DOT.

Here we agree but with the ST warranty there is much less incentive to file a warranty claim… with no mileage warranty and only time based (2 to 4 years in most cases) and prorated claims based on remaining tread not counting the first 3/32 of only 9 or 10/32 to start with… and the list of other disqualifiers…

But there are some exceptions. One is that if the tire manufacturer doesn't have an office in the US, the importer is supposed to act in the manufacturer's place. That means the importer would do the adjustments and have to do the government reporting. I think it is here where the problem lies.

Here we agree again and an example of exactly that was, what you don’t know can kill you when it comes to your tires… as the American importers of Westlake LT tires Foreign Tire Sales found out a few years ago, when mfg. Hangzhou Zhongce Rubber Company of China decided to intentionally leave out critical parts of the tire and cheat on testing to fraudulently DOT certify Westlake, Telluride, Compass and YKS tires

But I find it interesting that both Goodyear and Maxxis are large enough to have their own warranty centers and obviously would be required to report the data to the DOT - and yet, there doesn't seem to be any reaction to this data by the DOT - and I wonder why.

Good question…

I have several theories, but there isn't enough data to give credence to one over the others.

I find it hard to trust any tire company who’s marketing is meant to deceive and full of half-truths… that best describes the well-choreographed ST tire marketing schemes …

It also describes the new aging theories (3 to 5 years) used by the ST tire industry marketing... not a lie but not true either…

JJBIRISH wrote:
....As far as you assertion that the ST could pass some of the test… maybe… But I doubt the ST tire would pass that test either… sure it would only be 110% of its rated load for that psi but it would also be at 10 MPH above its maximum rated speed…......

CapriRacer wrote:
JJBirish,

There are a number of items in your post I would like to comment on, but in the interest of brevity, I’ll only focus on only one – one that I think is the key difference in our understanding of the DOT testing requirements. Perhaps we can find common ground.

First, I hope it is clear that tire “size” plays a large role in the rated load of a tire regardless of tire type. Put another way, larger tires have more rated load than smaller tires – all other things being equal. In trying to compare rated loads of tires of different types, we need to also compare tires of the same “size”. I put the word “size” in quotes because the letters in front of the numbers (in my view) also are part of the “size” as they delineate the type of tire involved.

When it comes to comparing LT tires and ST tires, there is a problem – very little commonality in “size”. I’m going to chose a “size” that is common to both LT’s and ST’s – 235/85R16 Load Range E:

ST235/85R16 LR E: Max Load 3640# at 80 psi – with a speed restriction of 65 psi.

LT 235/85R16 LR E: Max Load 3042# at 80 psi – and a common speed rating is Q = 99 mph.

Notice the difference in rated loads and speed restrictions. I hope it is obvious that a tire’s speed capability is inversely related to its speed – that is, the higher the speed, the less load it is capable of carrying (all other things being equal) – and that is reflected above.

So let’s take one of the DOT required LT tests and see how that plays out as far as load goes. How about this one:

JJBIRISH wrote:
.....=================================================

Category B Endurance Test:

(LT "E" tire at 50 PSI)
4-hour test: 85% of tire maximum load rating at 75 MPH
6-hour test: 90% of tire maximum load rating at 75 MPH
24-hour test: 100% of tire maximum load rating at 75 MPH

……..

For an LT235/85R16 Load Range E, the last step is 3042# load.

But for an ST235/85R16 Load Range E, that’s only 84% of its rated load. Or put another way, it is only 110% of the maximum load at 50 psi.

I think an ST tire can survive that last step.

Comments?