Goodyear Marathon Tires

[xrvr]

It does seem to be necessary to some who disagree with what is said. Seems to be a growing trend on the forums. We must remember that everything gleaned on the Internet must be looked at carefully. Lots of incorrect stuff there on all subjects. Jim

[HowieE]

Some people may like Goodyear Marathon Tires but I can't say much for them. I will let this picture say 1,000 words.

6am in SC the trooper asked me if i had a problem and I said not if you have a patch kit. He did not have a sense of humor.

[xrvr]

Not funny, trailer okay? Jim

[r carl]

Originally Posted by J. Morgan

Does it make me bad if I towed my ST tires in excess of 75 MPH frequently when crossing Texas?






1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

My Yokohama's have seen 90mph.

[CapriRacer]

Originally Posted by gmw photos

First of all, I'm not trying to pick a fight here. Second, I have no dog in this fight anyway because I don't buy ST tires. Having thrown those disclaimers out there, I think the key word in the above quote is "confusing".

Here is the quote from the Goodyear product service bulletin issued to dealers:

"Goodyear Marathon Special Trailer tires, with the “ST” size designation, are speed rated at 65 MPH (105 km/h) under normal inflation and load conditions."

....it then goes on to say:

"If Goodyear tires, with the ST designation, are used at speeds between 66 and 75 mph (106 km/h and 120 km/h), we recommend the cold inflation pressure be increased by 10 psi (70 kPa) above the recommended pressure based on the trailer placard for normal inflation and load conditions."
===============
Now then, to me, the confusing part of this is that the "implication" is the consumer could increase the inflation to 75psi. I suspect that is NOT what Goodyear is trying to say however. What they "are" saying is the inflation can be increased 10 psi "above the recommended pressure based on the trailer placard for normal inflation and load conditions".

In other words, they may be saying you could literally increase the inflation pressure 10 psi above what the load/inflation table states is the acceptable minimum.

So for instance, if the load/inflation table says that you could run 55 psi for the given specific load, then you could run 65 mph at 55 psi. To increase your speed to 75 mph, you could increase the pressure to 65 psi. Further, you cannot assume an increase in load capacity by this pressure increase, only a speed capacity increase.

Hopefully Roger or Barry will weigh in on this, but I personally have not seen a tire manufacturer that "allows" for tires to be inflated beyond the psi stated on the tire sidewall. I will stand corrected on that however if one of the tire engineers say that I am in error on that.

geo

Allow me to start in a different spot.

The load carrying capacity of a tire is affected by a great many things. We're all familiar that tire size (physical dimensions) and inflation pressure have an effect. Those are delineated in the tables.

But there are other things - and generally offered in the form of a different table - or a modification of the table. These separate tables or modifications to existing tables are for conditions DIFFERENT than delineated by the table heading.

For example, a P type tire table is for typical highway speed on relative smooth paved surfaces on softly sprung vehicles. The modification for light trucks is a derating of 10% for more stiffly sprung vehicles on less smooth surfaces at slightly slower speeds (what a pickup truck is normally used for). For the sake of simplicity, trailer application is included in that.

In the case of the ST tire table, the changes for speed could have been done in a couple of different ways: An increase in inflation pressure or a reduction in load - which from a tire engineer's perspective is the same thing - deflection. Higher speeds reduce the load carrying capacity - or stated from the other direction, higher loads result in less speed capability at a given inflation pressure. That is what the notes on the Goodyear load table are about.

BTW, those notes are taken directly from the Tire and Rim Association (TRA) Yearbook load tables - and here is where Roger and I disagree - they would apply regardless of who manufacturers the ST tire. The reason Roger and I disagree is that some manufacturers may not want their tires operated in any condition other than what THEY publish (I presume for legal reasons) - where I am coming at this from the theoretical point of view about how tires behave.

Now let me address the issue of increasing the inflation pressure. If you look carefully, you will see that the the sidewalls of tires state a maximum load - and either a maximum inflation pressure - OR - a pressure where this max load occurs - like this:

Max Load XXXX, Max pressure YY

- OR -

Max Load XXXX at YY pressure.

Note that the first way doesn't say what the relationship is, and the second way doesn't say what the max pressure is.

Side note: Occasionally, some manufacturers will use this form: Max Load XXXX at Max pressure YY. I think this is incorrectly stated, but I am willing to accept they are trying to prevent people from overinflating the tire.

I can explain why it is OK for Goodyear (and the TRA) to specify an inflation pressure increase beyond the max stated in the table, but the explanation involves some engineering concepts that are just too long for a post like this one. (After having written that, I think I will do another post on this subject AFTER folks have digested this one!)

Soooooo, the Goodyear ST tables have included some notes if it is desired to operate at a speed higher than 65 mph that the table specifies.

So, you may say, why is this so complicated. In the case of automobiles, the car manufacturers have done a good job of sizing the tires and defining what is needed for their vehicles - in the form of the vehicle tire placard on the driver's doorpost.

In the case of pickup trucks and SUV's, manufacturers of those vehicles haven't done as good of a job in the past, but as of 2008 have addressed the issue to the same level as the car manufacturers.

But trailer manufacturers are behind. In the past, their tire specifications (size and inflation pressure) were marginal - and in some cases worse than that. Trailer manufacturers do not have the extensive feedback system that car and pickup truck manufacturers have (dealers and the warranty system), so in most cases, they don't know there is an issue. To complicate matters, they slough off tire issues to the tire manufacturer - and the local tire dealers frequently don't handle off brands, so tire sizing issues don't get reported to where changes would be made.

That is why it is important to report tire failures to NHTSA. They are the government agency responsible for safety. They are NOT going to address issues they don't know about. Whether it is the trailer manufacturer under specifying or the tire manufacturer underdesigning, is for NHTSA to investigate.

[CapriRacer]

Originally Posted by HowieE

Some people may like Goodyear Marathon Tires but I can't say much for them. I will let this picture say 1,000 words.



6am in SC the trooper asked me if i had a problem and I said not if you have a patch kit. He did not have a sense of humor.

I am sure Roger will look at this photo and do the same thing I am doing.

First, I am not trying to pick on HowieE. I am trying to explain what I see in the photo and how that relates to tire failures.

Notice in the photo that there are strings of fabric coming off the sidewalls. The configuration is typical of a tire operating with little or no inflation pressure - commonly called a *Run Flat*. The question is what caused the tire to go flat.

I notice the tread (and belt package) appears to be in one piece (although we can't be sure if it is in the form of a hoop or in the form of a flat strip) If the tread (and belt package) are a hoop, then it is very likely that there is a puncture - and if we had all the pieces in front of us, that's what we should look for.

If the tread (and belt package) are in the form of a strip (and it kind of looks like it might be), the question is: Did the tire separate on its own or was it damaged such that the tread detached? I'd need a much closer examination to determine that. One possibility is that there was a slowly leaking puncture - and just like the above, it is something we should look for.

Just so we are clear on this, I am not trying to place the blame on HowieE, nor am I trying to absolve the tire manufacturer of blame. I am just expressing that there are things that happen on the road that could cause a tire failure that are just a part of the risk of operating a vehicle on the highway.

[Tireman9]

Originally Posted by Top

Sometimes when we feel offended we get a bit touchy, eh?

Steve is talking about the Michelin LTX MS2 P235/75/15XL and the Pirelli Scorpion LT235/75/15 LRD that I linked.

Ya I had a bad day yesterday. My Bad.

[Tireman9]

Originally Posted by HowieE

Some people may like Goodyear Marathon Tires but I can't say much for them. I will let this picture say 1,000 words.

6am in SC the trooper asked me if i had a problem and I said not if you have a patch kit. He did not have a sense of humor.

Here is an analysis of a somewhat similar tire on my blog July 22 2012. It was even on an Airstream so that might satisfy some here.

HowieE, Any chance you have a higher res picture. I see some parts of your tire that may provide a clue but the areas of interest are out of focus.

If you don't have my email (posted on my blog under my picture) I would be happy to do a "visual inspection" but need better quality shot.

[gmw photos]

Ok forum tire junkies, I stand corrected on my thoughts regarding inflation of Marathon tires. I have been educated by a tire engineer there are some conditions in which a user can in fact inflate a tire to 75 psi, even that tire has 65 psi embossed on the sidewall.
Learn something new every day.

[FishinHatteras]

This is probably one of the best threads I have read on here in quite some time.

Now I have a question or two for those that have pushed the GYM's into the ditch where they belong IMHO, and have moved up to 16" tires please? My MS2's arrived today, rims will be here on Friday...so, my ? is, Did you find that your hitch needed adjustment after the tires were mounted? And finally, how much clearance do you have in your wheel well with the 16" tires mounted?
Thanks everyone for this detailed discussion. I have learned a ton of information, and it's very obvious, ALOT of you guys know WTH you are talking about. Good company to keep!

[J. Morgan]

Originally Posted by r carl

My Yokohama's have seen 90mph.

I put my Yokohama tires on last week, (thanks for the tip RCarl) they haven't moved an inch yet, but I will give them a good tryout on the way to southern AZ in a week or so...

My biggest beef with my old ST tires was the tread life...


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[J. Morgan]

Here is my take.

Modern tires can and do "just fail" on occasion, but in the vast majority of cases when they fail they are, or they have been run flat, or they have at some point received damage from a road hazard, curb, etc.

This is just my experience.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[HowieE]

Originally Posted by Tireman9

HowieE, Any chance you have a higher res picture. I see some parts of your tire that may provide a clue but the areas of interest are out of focus.

No other pictures. That was pre digital. I think that was a result of a rim roll on a tight turn the night before. Something one has to watch with a tri axle and rough pavement.

On a return trip from Nova Scotia my friend called me when he got home saying he could not get his spreader between the tires on the passenger side. He thought he had bent an axle. I suggested he measure the dia. of the tires. They had each grown over an inch in dia. Had he driven another 10 miles he wuld have lost both of them. And for the record there is no one I know that doesn't check his running gear more often that he does.

In general if one has had any amount of mileage under their belt with Marathon Goodyear tires you will know why we don't use them. They were poor before they went to China and did not improve with that relocation.

[SeeMore]

"Carlisle is owned by.... ????'

Looking beyond Wikipedia's outdated info, I found an article dated Dec 31, 2013 stating Carlisle Industries sold its 'Transportation Products' division to American Industrial Partners. American Industrial Partners then operated the business as CTP Transportation Products (www.carlisletransportationproeucts.com) in 2014. Ownership morphed again in 2014 and the holding company who now operates CTP (headquartered in Franklin, Tn) is The Carlstar Group LLC. The Carlstar Group is transitioning production to the Americas as fast as financially viable. Some tire products are already being made using 'unused capacity in domestic tire manufacturing plants'????

Maybe folks need to check the label when deciding China versus US/Canada/Mexico on Carlisle tires now.

[Tireman9]

Originally Posted by HowieE

No other pictures. That was pre digital. I think that was a result of a rim roll on a tight turn the night before. Something one has to watch with a tri axle and rough pavement.

On a return trip from Nova Scotia my friend called me when he got home saying he could not get his spreader between the tires on the passenger side. He thought he had bent an axle. I suggested he measure the dia. of the tires. They had each grown over an inch in dia. Had he driven another 10 miles he wuld have lost both of them. And for the record there is no one I know that doesn't check his running gear more often that he does.

In general if one has had any amount of mileage under their belt with Marathon Goodyear tires you will know why we don't use them. They were poor before they went to China and did not improve with that relocation.

Too bad. Here is a picture from a "Blowout" on an Airstream.
The pictures were captured from a video that was high enough quality I could see the evidence that supports the theory of Run Low. The full report is on my blog

[jcanavera]

One other thought about inflating your Marathon to 75 PSI to accommodate higher speeds. We always talk about cold inflation temperatures so in actuality the tire inflated to 75 psi may be carrying more inflation due to road and air temperatures. The side we haven't talked about is wheels. Some Airstream aluminum wheels have inflation limits stamped on them. Lets say your wheel is stamped at 80 psi. You inflate the tires to 75 and on a hot summer day that tire pressure exceeds 80 psi. Do wheel manufacturers build in a factor to cover higher pressures generated by heat? Personally inflating an ST tire to 10 psi over the limits of the sidewalls gives me willies if that inflation of the tire is pushing close to the limits of the wheels themselves.

I've not heard stories about wheel failures due to overinflation but on the other hand I've never met anyone who knowing carries tire pressures over the max inflation instructions.


Jack

[FishinHatteras]

Amen. Excellent point Jack.
No way in hell am I inflating a tire over the capacity rating stamped on the sidewall.

[twh731]

RCarl and JMorgan, which Yokohama tire are you using? I love the Geolanders on my Jeep. Thanks Tom

[ROBERT CROSS]

Originally Posted by jcanavera

One other thought about inflating your Marathon to 75 PSI to accommodate higher speeds. We always talk about cold inflation temperatures so in actuality the tire inflated to 75 psi may be carrying more inflation due to road and air temperatures. The side we haven't talked about is wheels. Some Airstream aluminum wheels have inflation limits stamped on them. Lets say your wheel is stamped at 80 psi. You inflate the tires to 75 and on a hot summer day that tire pressure exceeds 80 psi. Do wheel manufacturers build in a factor to cover higher pressures generated by heat? Personally inflating an ST tire to 10 psi over the limits of the sidewalls gives me willies if that inflation of the tire is pushing close to the limits of the wheels themselves.

I've not heard stories about wheel failures due to overinflation but on the other hand I've never met anyone who knowing carries tire pressures over the max inflation instructions.


Jack

Good point Jack.

Ck the inside of your Alcoa wheels...



Bob

[r carl]

Originally Posted by twh731

RCarl and JMorgan, which Yokohama tire are you using? I love the Geolanders on my Jeep. Thanks Tom

RY215 Commercial Light Truck Tires | Yokohama Tire Corp.