Marathon and other side-wall failures

[jcanavera]

Originally Posted by bhayden

Failures of more than one tire at a time don't necessarilly indicate a quality problem with the tire. The failure of the first tire put's added stress on the rest of the tires. A tire on a tandem axle trailer could be low on air for an entended period causing the other tire on that side to carry all the load. That might actually be the first to fail and then the tire already low is suddenly carrying nearly half the total trailer weight. No tire is going to tolerate that for long.

-Bernie

Bernie, this brings up an interesting point. If you notice in your Airstream documentation they note that if you have to tow with only one tire on a tandem, you go no faster than 45 mph.

What most people don't know is that load capacity of a tire is also affected by speed. Not all tire manufacturers will have a public chart but one I have from a manufacturer shows that the load capacity of a tire actually increases as the speed drops. That's why the recommendation is to slow down when towing on one tire, since that tire can accomodate the heavier load if the speed is kept down.

Technically those folks exceeding the speed rating for their tire are unknowingly causing their load capacity to be reduced thus the potential for tire failure increases. For the Marathon tire that rating is 65 mph.

Jack

[bhayden]

The speed rating it sort of confusing. It really should be graded according to heat disipation. I'd be surprised if any of the ST tires would manage an A grade for Temperature (Cooper maybe). The load rating is at 65mph which makes sense as that's about the legal limit for trailers on most highways. But also of note is that in many parts of the country you're load capacity even at 65 is diminished by heat. Towing across South Dakota in the summer at 60mph may actually put more stress on the tire than 70mph in cooler climates. That's why I'm not all to impressed with any of the ST radials. It would seem that the only way to get any margin is to buy one or two load range greater than you need but continue to run them at or at least close to the orriginally recommended pressure.

It certainly doesn't help that all of the available sizes are undersize in relation to the original equipment 7.00x15 that most of the older trailers are designed for. Smaller tires mean more revolutions per mile which means more heat to dissipate from a smaller tire. About the only way to get back to the original design daimeter with the lower aspect ration of todays radial tires is to make the switch to 16" rims.

[Frank S]

Hi bhayden--Why not stay with 7.00-15 LT-D, which are still available, like I do?--Frank S

[Bob Thompson]

bhayden is absolutely correct. Heat is the key factor. The NHTSA tracked failures of the Firestone tires which lead to fatalities and found that far and away most fatalities occured in the southern states! see http://www-nrd.nhtsa.dot.gov/pdf/nrd..._TireAging.pdf

They were mostly in California, Arizona, New Mexico, Texas, Oklahoma, and Florida.

The lucky northerners in such places as North Dakota, Wyoming, Montana and similar states all added together had almost no fatalities related to the Firestone tires. However, Texas had 35 fatalities. Heat was the critical variable. It could be why so many southerners are up in arms about tire failures and northerners brag about the great service they get from their tires. As Beginner has pointed out repeatedly, speed rating is the key to how a tire reacts to heat and thus the key to durability.

This heat factor has the NHTSA testing tires in the Phoenix area to determine their ability to carry loads in elevated heat conditions in order to create a new more accurate test of tire aging.

[Dwight]

Here is a web site that has a lot of information about the Marathon:
http://www.goodyear.com/rv/products/marathon.html

[bhayden]

Originally Posted by Frank S

Hi bhayden--Why not stay with 7.00-15 LT-D, which are still available, like I do?--Frank S

That's certainly an option that I haven't ruled out. The bias ply tires on the trailer now tow just fine; Monarch, private brand tire made by, guess who... Goodyear.

The reasons for thinking I want to go radial:
Better milage: nice side benefit but not worth giving up more important qualities for.
Better grip in wet or winter driving conditons: maybe not with the available tread and tire compounds
Smoother ride: haven't noticed a big problem but if I can reduce wear and tear on the trialer it's a bonus
Better heat disipation: Important except this quality of radial construction seems to have been used to produce a cheaper rather than better tire.

Doesn't sound like there's a compelling reason to limit the search to radial tires, does it? Unfortunately the ST bias ply tires have the same problem as far as being built to a spec that limits travel to 65mph on nice spring days. Yes they have more plies but that's because they need them to overcome greater heat build up in the tire. One question I have is if the construction of the bias ply tires is less prone to catastophic failure; the kind of shrapnel condition that occurs when steel belted radials let loose. Steel belts are great at reducing the number of puctures due to road debris. However, when they do fail they can result in causing tremendous damage. Another question is resistance to the out of round condition caused when a tire sits in one place for an extended period. If memory serves that's more of an issue with radial tires but I could have that backwards in my swiss chesse mind

-Bernie

[Minnie's Mate]

Originally Posted by bheyden

Click on "Full specifications". Makes me wonder what will happen in a warantee situation. It's too bad as Cooper is the only manufacturer that I've seen give the Service Description. For the load range D tire it's 113S ( 113 = 2561pounds, S = speed rated to 112 mph). This is the way Passenger tires (P) and Light Truck (LT) are rated. I haven't seen any LT tires that come close to this rating so I think you're only choice are the Special Trailer (ST) type tires.

I don't understand the "speed rated to 112 mph". Does that mean the tire can be towed on the trailer going 112 mph or is that an equivalent to conditions on a car? What does it mean? Or is there any meaning to it in relation to a trailer?

[bhayden]

Originally Posted by Minnie's Mate

I don't understand the "speed rated to 112 mph". Does that mean the tire can be towed on the trailer going 112 mph

Speed ratings are certified maximum sustained speed designations. So, yes IF it's not too warm you can cross Montana at 112mph in your Airstream . Really it's just a relative scale to help determine the heat dissapating characteristics of one tire vs another. Here's a full explaination:

http://www.yokohamatire.com/utspeed.asp

Basicly Cooper has put their tire to the test and is willing to certify their product meets the standards required for ST tires and exceeds it in heat disipation.

-Bernie

[Beginner]

Well folks you all can continue to debate this until the "the cows come home". Nothing will ever be accomplished because no one wants to take the time to actually FILE A FAILURE REPORT WITH THE PEOPLE THAT CAN MAKE SOMETHING HAPPEN.
Go to this web site:
http://www-odi.nhtsa.dot.gov/cars/pr...callsearch.cfm
File your reports of failure.
These people are driven by numbers. Lets Choke em with numbers. Most of you are retired or blow a couple of hours a night on this thing, I do. So take 30 minutes and fill our a real complaint. Lets force the retesting of these tires.
Lets make something happen for the community in general.
There are two failures mentioned in this thread. There should be two complaints filed.
Come on folks, I'm the
Beginner
and I found a vehicle for complaints.
It slmost sounds like bad tires have been with us so lo long that it accepted as a way of life. Something to whine about about instead of our last surgery.
Still
Beginner

[scottanlily]

hello 85MH325 ,and others,

Fist of all I in many other tire threads have stated multiple times about the
tire of any type being overloaded ,too much heat causing the tire to come apart.I also respectfully would ask that you refrain from calling me reckless ,
there is plenty of information to support the failure of the tire we are dicussing .I don't think you speak for many others that have had tire blowouts ,If you do not want to look at noted failures that others have had
and your clearly discounting the idea that these reports are really false
or not worth taking note of ,thats your choice ,please do not discount
my knowledge or decision to research data that clearly shows some
problems . Do you really think goodyear is going to post failure information ?
Consumer reports research many things ,mostley cars and trucks .Should we then discount there reports also as anecedotal also ? read readers feedback in any rv magazine say trailer life ,where I read about the sob with the marathons ,4 blow outs bringing the trailer home ,new tires on it .That must be a fluke also ,I also stated that marathons on lighter trailers should be fine .I busted tires for a living ,was a tire adjuster ,needed
to find the failure ,identify the type of failure ,sidewall ,tread separation,or
and also note the reason if possible for the failure ,so I have alot of knowledge about tires .Feeling the tread ,the circumference of the tire ,checking for tread separations and irregular tread wear.The negative
response directed at me says it doesn't matter what you read or evidence
provided .you guys can put on whatever tires you like ,I have read many
posts praising marathon tires and ST tires with NO consideration for anything
else or any other brand of tire .Then if failures occurr well the curb must have damaged the tire or its this or that or somthing else .You give your opinions
that should not be questioned or Im reckless or the information can't be true.Then believe what you will ,do what you want .I say there are other
choices as others have .All here remember I am not the only person that has
talked about tire failures or talked about the rate of marathon tire failures
on these forums ,I have put out some thought about this issue and Because
it is popular to use this tire then ,it must be the greatest tire ever.Im trying to help educate and inform as we all here are doing .Bhayden stated most ST
tires are cheaply made ,so why don't you call him reckless ?? is that statement true? The fact of the matter is you like the marathon and my
knowledge and supporting information is irrelevent .These forums are for
knowledge sharing and I see that the popular knowledge is what we like.

Scott

[Kevbo10]

please pass the magic mushrooms... opps gotta go... rainbow's here...

[85MH325]

Ok, Scott... this is my last post on the matter.

The sky does NOT appear to be falling no matter how much folks proclaim it to be true.

Anecdotal evidence of tire failures, of whatever brand, are merely that; they do NOT amount to an indictment of that brand or model without a supporting statistically significant data sampling. To know whether Marathons fail more frequently than other brands, there needs to be research done into the failure rate. In other words, tire sidewall failures per X number of tires produced for Marathons as well as all of the competitors. That's the only way I can think of to know if the failures we see are in line with or are signficantly higher or lower than other tire brands, and reasonable conclusions drawn. Any conclusions drawn outside that kind of comparison really don't mean much. Even in the NHTSA article I linked to, it mentioned that the Firestone Wilderness AT tires failed much more frequently than the similar Goodyear tires on the Explorer. That's empirical, comparative evidence.

Drawing conclusions from incomplete data is sort of like saying that GM products are involved in more crashes in the U.S. than any other brand of car, so we should warn everyone not to buy them. And because they outsell all of the other brands, and there are more of them on the road, they probably are involved in more crashes than any other brand. Does that mean that GM products are inherently more dangerous? I don't think so. I think it just means that there are many many more of them out there TO crash. Crashes per X number of GM product built versus a similar other make of car would be a valid comparison.

Another similar example of making an analysis on anectodal data would be saying that there are valid reports of people regularly dying in hospitals; and since people regularly die in hospitals, I won't go to a hospital for treatment. If a specific hospital has an unexplained mortality rate significantly higher than another similar hospital across town, then there might be reason to avoid that hospital. Otherwise, there are many reasons that folks die in hospitals; few of which have to do with the hospital itself, or the care recieved there.

I merely said I have not seen any failure rate data on Marathons, or any other ST rated tire for that matter. I clearly said in my posts that I have Marathons on my Airstream. I also clearly said I have also had other brands on other trailers that performed equally well in trailer service.

You're drawing conclusions based on heresay (anectdotal evidence) , and not valid data (statistically significant sampling). No one is disputing that Marathons fail. All tire brands have failures. Before I can propose a conclusion that the Marathons have flaws in design or engineering, I need to see some valid data from which valid conclusions can be drawn.

I am neither supporting Marathons as "THE" tire, nor am I condemning them as "THE" tire to avoid. I'm just saying that I think you're drawing conclusions that aren't necessarily supported by empirical evidence; your conclusions are supported merely by anecdotal evidence you've heard and presented. I hope you understand the difference.

Roger

[Darrell Root]

Boy ,this tire debate can get heated-I know marathons came on my trailer from airstream. Even AS doesn't come out and say buy marathons-they only give a correct tire size in the manual. Maybe there isn't published data regarding tire failure on trailers. Proof doesn't always come in a publication. I've called several dealers regarding tires and all have been negative on the marathons even when they stocked them. Unfortunately there is not alot of alternative tires to chose from-but I'm looking.

[Action]

Scott,

What Roger and some others have said is you present the drama not the facts. Tires blow out all over. Due to age, loading, heat and some defects.

To say that 4 tires had a blow out and they were all one brand doesn't mean that they were defective. They may have been if they were a year old, filled at max pressure that morning, balanced last month and the total load was 80 percent of the rated capacity.

You offer none of that data and no one can determine what actually happened. Other than there was a tire failure. So to say there was failures and many of them doesn't mean much. And if you don't like Marthons is OK. We get your point.

However others may not agree with you if that is OK.

>>>>>>>>>>>>>>>>>>>>>Action

[scottanlily]

well 85mh325 ,
I hope it is your last word ,You insult me ,then make the firestone tire
comment ,post a link which does not support your position ? You can twist
and turn your words as you wish to your benefit .You have plenty of conclusions from your firestone link yet that does not even give you a concrete position to where you are at .If 50 people were injured and 25 died
and you still can't come to a conclusion ,then you won't on anything .Your post said the firestone tire MAY or MAY NOT have been a problem ,claimed it was the right rear tire only ,Said ford recommended low pressure etc.
Did Iread yourpost wrong? The link clearly and decisively stated firestone
said YES there was a defect ,so what are you saying ? they failed or not
cannot be both ,you are trying to be on both sides of this issue ,faulting me
will not change anything .I have experience in the tire field and yet ,
you discount me and all others as having no merit ,Does no good as I can
see to continue talking with you ,you are about being right no matter what .

Scott

[bhayden]

100,000 trailer tires sold per year
80,000 are Goodguy brand Sprinters
20,000 are Carpile brand Radical Trailers

800 complaints are filed regarding failure of Goodguy Sprinters
400 complaints, only half as many are filed regarding failure of the Carpile Radicals

What should we conclude? The Goodguys tire with twice as many failures (1% failure rate) is twice as good as the Carpile tire (2% failure rate).

Obviously I just pulled these numbers out of my rear axle but I hope that it illustrates what we're trying to convey which is the failure reports can't be used to draw any conclusions without more data.

As far as the Goodyear Marathons having only two plys in the sidewall I beleive that's true of all radials. It's inherent in their construction. Adding more material would result in more heat build up and defeat the advantage of radial design. ST radials use larger diameter cord in the plys in order to handle the higher inflation pressure necessary to provide the increased load carrying capacity.

Radial design allows the tread to be engineered independently of the sidewall. For this reason radials can use extra material, usually steel belts to reinforce the tread. While this provides improved pucture protection, less heat and rolling resistance and improved traction tread separation seems to be the most common cause of catastrophic tire failure.

Bias ply have thicker sidewalls and are going to be more tolerant of damage from something like scrubbing curbs. Flexing in the sidewalls directly affects the tread area resulting in more heat and a loss of traction. From most accounts it also produces a softer ride. Radials allow side to side movement that keeps the tread patch in contact with the road but at the expense of a harsher ride. FWIW it's bias ply that are more prone to "cupping" which is flat spots from sitting in one position.

Radials, because of the way the sidewalls are designed to flex are built with lower aspect ratios. That's why we can't get 15" radials that match the diameter of the old 7.00-15 bias ply tires. Note that car manufacturers have been steadilly increasing rim size since the introduction of the radial. Trailers on the other hand seem to be stuck in the 60's.

-Bernie

[Beginner]

I just checked the web site:
http://www-odi.nhtsa.dot.gov/cars/pr...aintsearch.cfm
This is a Federal Government Web site, not affiliated with any tire manufacturer in any way shape or form.
I see complaints in the forums about the Marathons but there are no complaints on file about the Marathon that I could find in passing.
Yes the squeaking wheel gets the grease, but only if you know whose house to drive by at 3 am when its squeaking.
Want to do something constructive?
Go to the National Highway Transportation Safety Administrations web site and file an official complaint.

http://www-odi.nhtsa.dot.gov/ivoq/

We pay these people, lets get some work out of them.
File a complaint. Give a government worker something to do.
Beginner

[Steve Heywood]

I agree with the assumption that since more GoodYear Marathons are installed on new travel trailers/fifth wheels than all others COMBINED that they would be over-represented when comes to reporting failures.

I have four 2-year old 225/75-15 LRD Marathons on my Excella and have complete faith in them. My trailer typically puts 73-7500 lbs on the tandems which is below the capacity of four load range C Marathons. Airstream recommends 50 PSI cold for my trailer which again is within spec for LRC tires. I run 50 PSI as an absolute minimum COLD and frequently adjust slightly higher for hot weather trailering. I check my tires EVERY TIME I pick it up from storage. I also check them 2-3 times a week while on the road. The prevailing reason for tire failure is UNDERINFLATION!!! Remember the Explorer/Firestone fiasco??

I did a quick search on Tire Rack (by far NOT the only source for information) and here's what I found:
Yokohama sells a 7.00-15 LRD tire, the RY215. Good for 2040 lbs @ 65 PSI. This tire would be marginal for my trailer but would work well on an older Airstream that was originally equipped with 7.00-15s.

The only "non-ST" rated 225/75-15 I found that would work was an XL rated Pirelli Scorpion STR A (I'm sure that there are others). 2094 lbs @ 50 PSI. I run this tire (in a larger size) on my F250 and like them well enough that I bought 2 more when I severely damaged one 3 weeks ago.

[Frank S]

Hi--I've been following this thread with interest, and from the comments above here is my conclusion. I believe A/S people are basicly honest. The reason trailer tires do not show up on the Gov. web site is that most people realize that their tire failures were really the result of overloading, underinflation, or tire age.--Frank S

[bhayden]

Originally Posted by Steve Heywood

I did a quick search on Tire Rack (by far NOT the only source for information) and here's what I found:
Yokohama sells a 7.00-15 LRD tire, the RY215. Good for 2040 lbs @ 65 PSI. This tire would be marginal for my trailer but would work well on an older Airstream that was originally equipped with 7.00-15s.

Thanks for the info. The Yokohama didn't show up when I searched by brand. I had to put in the size. Turns out Yokohama also makes the Y742S:
http://www.yokohamatire.com/tbs_tire....asp?tireID=62
Interesting thing about this tire is it's M+S rated for winter driving AND, if I'm reading it right a 7.00R15 steel belted radial! I thought all the 7.00-15 tires were bias ply.

-Bernie