Towmax blown tires

CapriRacer wrote:
To add more fuel to the fire:

Many people who are reporting that they "ONLY" changed from ST tires to LT tires neglect to mention they also changed a) from size 235/80R16 to 235/85R16 (The aspect ratio change also affected the load carrying capacity) and b) they changed from a no-name brand to a name brand.

In the case of Goodyear G614 the aspect ratio seems to be only on paper since the tire is listed by Goodyear as being the same physical size as the Carlisle ST 235/80-16. Several people have gone to Sailun, which hardly qualifies as a "name brand", but the jury is still out on that so far. I would consider that Carlisle is a "name brand", and Sumitomo AFATG.

So what's your point?

Barry, I do not think Goodyear would like you calling their Marathon a no name product. They are most likely the single largest manufacturer of ST tires. It is a little surprising that Goodyear has stayed the course on ST tires when the other major US makes bailed years ago. That would indicate that there are BIG BUCKS in building cheap tires, as no major company does anything anymore without a close look at the bottom line.

And if Sumitomo owns TowMax, and Sumitomo is a large multi-national corporation from Japan, I do not believe they are a no name company. And again a company that would be looking at everything they produce and its effect on profitability.

Chris

To add more fuel to the fire:

Many people who are reporting that they "ONLY" changed from ST tires to LT tires neglect to mention they also changed a) from size 235/80R16 to 235/85R16 (The aspect ratio change also affected the load carrying capacity) and b) they changed from a no-name brand to a name brand.

ol Bombero-JC wrote:

Me Again wrote:
While we are discounting weight, maybe we should decide which of these three trailer tires we would what on our 7K axles?

41.7lb Carlisle ST235/85R16E rated to 3640@80lbs poly carcass
44.8lb Carlisle ST235/85R16F rated to 3960@95lbs poly carcass
57.5lb Goodyear G614 RST LT235/85R16G RST rated to 3750@110lbs steel carcass

Chris

Hmmmmmm -

"Me Again" - Chris...... are you
part of the Eagle family (Fast Eagle's kin) or just a buzzard beating a dead horse (carcass)?..:@

~

NO! I would take the G614 without a second thought! And how could a being that has not seen the light of day have kin folks?

Chris

Me Again wrote:
While we are discounting weight, maybe we should decide which of these three trailer tires we would what on our 7K axles?

41.7lb Carlisle ST235/85R16E rated to 3640@80lbs poly carcass
44.8lb Carlisle ST235/85R16F rated to 3960@95lbs poly carcass
57.5lb Goodyear G614 RST LT235/85R16G RST rated to 3750@110lbs steel carcass

Chris

Hmmmmmm -

"Me Again" - Chris...... are you
part of the Eagle family (Fast Eagle's kin) or just a buzzard beating a dead horse (carcass)?..:@

~

While we are discounting weight, maybe we should decide which of these three trailer tires we would what on our 7K axles?

41.7lb Carlisle ST235/85R16E rated to 3640@80lbs poly carcass
44.8lb Carlisle ST235/85R16F rated to 3960@95lbs poly carcass
57.5lb Goodyear G614 RST LT235/85R16G RST rated to 3750@110lbs steel carcass

Chris

CapriRacer wrote:

Let's take the infamous Firestone/Explorer situation some years back. The source of the problem was the material properties of the belt edge insert - AND - the thickness of the belt edge insert. The difference in weight between tires that performed adequately and tires that didn't was well within tire to tire variation. It was immeasureable. PLUS, tires produced in one plant didn't perform the same as tires produced in another plant.

Interesting that you bring this up. Just about all ST tires have a similar tread and over shape with narrow shoulders, except for one newly noted tire, the Maxmiler! which has a full width tread and departs from what we call the baseball shape of most ST tires. It will be fun to watch how this offering fairs. I believe the Denman ST that went away was shaped more like this Maxmiler and got pretty good reviews from users.

Chris

gitane59 wrote:

"Once more, I understand your position that theoretically tire durability isn't measurable by weight, however in a real life practical application the durability 2 tires, one a 37lb ST and one a 56Lb LT will be dramatically different on the same fifthwheel and I do not accept the position that weight has no bearing on this different performance. Yes the entire tire construction is different, leading to a higher weight but that is precisely why they perform better."

Because we as consumers can not see inside a tire to see how it is made, we need some other way to better determine a good or bad product. Over the last 9 years that I have been following these tire issues closely, after buying a new trailer that had Kenda Klever LT235/85R16E chinese maypop tires, I came to the conclusion that lack of tire weight increased the number of reported problems. That is what we call gathering real world stats. Cost is another fairly good item to track, and the cheaper the tire is generally there are more complains.

All tires look pretty much the same from the consumers view. They are black and round! So why not use history, weight and cost as a measure of quality?

Many posters have stated: "After multiple ST failures, I switched to LT tires and the tire problems went away without me changing anything else!" If only "you know who" had made this switch also, tire treads disagreements would have greatly declined over the years. And we would not need an engineer to try to insert engineering logic into a simple problem that has a simple solution. GET RID of the product, as it does not work well if you want to see America with your trailer.

Chris

Lets see, my truck weights around 7K pounds and is on tires that weigh in at around 46 pounds each and my trailer weighs 12,400 give or take and you want me to tow it around on tires that weigh 35 pounds. No thanks, I will stay with my R250's that weigh 59 pounds or the XPS RIBs I ran 6.5 years that weighed 56 pounds.

I hate to disagree with you on the subject, but the currently available overrated ST tires on mid to larger 5th wheels just do not cut it in my book. They present just to many compromises to be a KISS product that I can trust in my type of use. Which in the last 5 years has been 3.5 day fall trips to Arizona and 3.5 day returns the 1650 miles in the spring. Trailer sits as each end for months, and then is asked to do the road trip. At the North end, it comes home for a few weeks and then is moved to a RV Park a hour away. Tire pressure gets check twice a year! At each stop on the highway the tires get SHOT with my infrared heat gun. Trailer tires run in the 115-120 degree range and truck LT265/75R16E run 120-125 degrees. And yes I believe Michelin when then claim that the steel carcass XPS Rib runs cool and has a low rolling resistance. Other than a wider tread, what else explains the truck tires running warmer than the trailer tires, other than the poly verses steel ply carcass.

When clipping off a 500 mile day I do not want to spend that 10 hours of driving wondering when the next tire is going to fail.

I think you nailed it in the 3nd tier materials and processes, however I call it a bottom feeder product. Many report their ST running in the 135-150 degree range and with 3rd tier materials that may be JUST TO HOT! I still think however if you stay with the overall ST design and loading, and use the best materials and processes, you will still have a tire that fails a lot. You are just asking to little to do to much with the inflated ratings. Like I said in another post, instead of getting a 10 percent increase in capacity, these cheap tires should get a 10 percent decrease in capacity. Plus you need to replace them every 3 years and/or 8-10K miles

A person goes out and buys a new 5th wheel that might cost between 60 and 100K and gets tires that the manufacturer pays maybe 50-75 dollars each for. Makes no sense, we would not stand for that on a new car or pickup, yet it has been happening on trailers for years.

When problems occur in the first year or two the user is blamed for not maintaining their tires correctly, which might have one hint of truth in it. Many post about having to air up their ST tires routinely. In 6.5 years with the XPS RIBs I had one tire one time need air added, and I re-seated the the valve core and never had that reoccur.

We as consumers just need to say no to these 3nd tier products!

Chris

CapriRacer wrote:

gitane59 wrote:
To CapriRacer and FE:
What is not a joke is to compare sidewall strength of a ST tire and a LT tire side by side.
If after doing the comparison regardless of tread depth and the slight weight differences tread depth may produce the vast difference in sidewall strength and stiffness is not obvious to you both then we have no hope in changing your minds.......

Just so you know, I am a tire engineer and am very familiar with the strength of tire sidewalls.

But we aren't talking about sidewall failures. We are talking about failures in the belt (tread area). The strength of the sidewall has nothing to do with this type of failure. This type of failure has everything to do with the way the belt area is configured - and that is not at all related to weight.

Am I supposed to believe that sidewall heat buildup due to excessive flexing in ST tires does not contribute to heat buildup in the tread area and subsequent premature tread separation and belt failures? I'm sorry, engineer or not I can't accept in real life your theoretical analysis.

This is likely the result of third tier tire manufacturing materials and processes (which includes 1st and 2nd tier tire manufacturers using 3rd tier materials and processes.)

I fully understand your position here that subpar manufacturing or outright manufacturing defect from specific manufacturers. But that's not what were talking about. We are talking LT versus ST tires performance on heavy 5'vers and the way the ST manufacturers promote their products as the only game in town for tow behind rv's


That's why I find this whole discussion about tire weight so funny - the key to tire durability isn't measureable by weight.

Once more, I understand your position that theoretically tire durability isn't measurable by weight, however in a real life practical application the durability 2 tires, one a 37lb ST and one a 56Lb LT will be dramatically different on the same fifthwheel and I do not accept the position that weight has no bearing on this different performance. Yes the entire tire construction is different, leading to a higher weight but that is precisely why they perform better.


I hope this explains the positions I have taken on the subject - but more importantly, the strategy used to try to fix this problem is dependent on what the true nature of the problem is. I see my role as trying to educate people as to this nature - and in particular, where they are going off on the wrong tangent.

While I do appreciate your theoretical engineering analysis and knowledge of the different variations and designs of various tire types real life experience can not be completely denied and ruled out when many people including myself have switched from ST to LT tires on the same RV making no maintenance process changes and all tire un-expained tire failures have ceased.

While we are at it I will state that as an engineering technologist it is my role in many instances to apply and make work in real life an engineers theoretical plans