marathon tires are junk

[steelpony5555]

I can agree Marathon tires are great,,,,,,,if they are on a bike trailer, car hauler, box trailer etc. But yes, they are definitely the wrong tool for a Montana. Most of these rigs put those tires at or very near their max load. Then you put them on a trailer that is meant to go cross country where the interstate speed limit is 65+ mph...... Not very smart, nope don't got a degree in rubber physics, but I do got common sense. Now this is very long so I apologize....but it shows that YES LT tires are held to a higher standard. I have tried to follow this guys summary on the government pages which of course is a lot of mumbo jumbo but it appears to be correct.... It only makes sense that vehicles carrying people would have stricter standards then trailers that just carry stuff.


SUMMARY OF FINDINGS & CONCLUSIONS

I found the testing requirements for both the ST and LT tires at the Federal Motor Carrier Safety Administration (FMCSA) webpage.

The testing for each tire is comprised of (1) bead unseating resistance, (2) strength, (3) endurance, and (4) high speed performance.

The testing for (1) bead unseating resistance and (2) strength were identical for tires representative of moderate to heavy 5th wheels and thus no advantage is given to either tire type.

The testing for (3) endurance was found to be significantly different between the ST and LT tires.

Both the ST and LT are put through the same initial pressure, time and load profile. The total profile lasts 34 hours of continuous run time starting at 85% of rated load and ending at 100% of rated load. To further stress the tires, a load range E tire (nominal 80 psi rating) is tested at a reduced pressure of 60 psi to induce additional load on the tire during testing. (This is reasonable that testing should be conservative.)

But now the endurance testing diverges significantly.

The ST tire is tested at this pressure, time and load profile at 50 mph. After that, the ST test is over.

The LT tire is tested at this pressure, time and load profile at 75 mph. This is a 50% increase over the ST and will induce significant additional load and heating on the tire during testing. After that, the LT test is not complete. Next a “Low Inflation Pressure Performance” test is performed for the LT tire only. The tire pressure is decreased to 46 psi and the tire is immediately run for an additional 2 hours at 75 mph and 100% of rated load.

Thus, the LT tire endurance test is drastically more intense than the ST endurance test.

The testing for (4) high speed performance.

The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a 90 minute speed/time profile.

The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire.

However, the LT tire is tested at significantly higher velocities when compared to a ST tire (99 vs. 85 mph maximum speed). This is a 16% advantage to the LT tire.

Thus, again the overall test for the LT is more rigorous than the ST test.

Conclusion:

It is reasonable to conclude that these test requirements force the tire manufacturer to construct an LT tire more substantially than an ST tire. This is also a reasonable explanation for the same size LT tire is rated at a slightly lower maximum load than a ST tire.

And now, for those of you who need to know all the details, read on!

REFERENCES

The references for my evaluation may be found at the Federal Motor Carrier Safety Administration (FMCSA) webpage:
ST tire standard may be found at FMCSA Part 571, subsection 109.
http://www.fmcsa.dot.gov/rules-regul...0163348008f295
LT tire standard may be found at FMCSA Part 571, subsection 139.
http://www.fmcsa.dot.gov/rules-regul...0163348008f2a9
Part 571, subsection 139 references Part 571 subsection 119 which can be found at:
http://www.fmcsa.dot.gov/rules-regul...0163348008f29d

QUICK NOTES

Each standard for the ST and LT tires has definitions, significant constraints on labeling, etc. that I will not address. There are also tire conditioning (temperature), tire break in, etc. that are the same or similar for ST and LT that I will not address. The details are in the references.

The (3) endurance, and (4) high speed performance tests must not result in tire failure. Tire failure includes visual evidence of tread, sidewall, ply, cord, inner liner, or bead separation, chunking, broken cords, cracking, or open splices, not just a blowout.

TESTING - BEAD UNSEATING RESISTANCE

ST Tire: (reference paragraph S5.2.2)

The tire is mounted horizontally and a vertical load is applied to the tire’s outer sidewall at a rate of 50 mm (2 inches) per minute.

Increase the load until the bead unseats or a specified value is reached.

Repeat the test at least four places equally spaced around the tire circumference.

LT Tire:

Paragraph “S6.6 Tubeless tire bead unseating resistance” references the ST tire procedure noted above.

Conclusion:

The testing for bead unseating resistance is identical for a ST and LT tire.

TESTING - STRENGTH

ST Tire: (reference paragraph S5.3.2.1)

Force a 19 mm (3?4 inch) diameter cylindrical steel plunger with a hemispherical end perpendicularly into the tread rib as near to the centerline as possible, avoiding penetration into the tread groove, at the rate of 50 mm (2 inches) per minute.

Compute the breaking energy for each test point by means of a provided formula.

LT Tire: (reference paragraph S6.5.2)

Each tire shall comply with the requirements of S7.3 of 571.119, which is tires for vehicles weighing 10,000 lb or more. Per S7.3 of 571.119 for our example tire, the testing is the same as the ST tire procedure noted above.

Conclusion:

The testing for strength is identical for a ST and LT tire.

TESTING - ENDURANCE

The following is for a ST or LT tire of less than nominal cross section less than or equal to 295 mm (11.5 inches) which is typical of a 5th wheel application.

ST tire: (reference paragraph S5.4.2)

There are specifications for the contact of the tire mounted on a test axle and steel test wheel after the test that I will not address because they are similar for the ST and LT.

Inflate a load range E to 60 psi. (410 kPa)

Conduct the test at 80 kilometers per hour (km/h)(50 miles per hour) in accordance with the following schedule without pressure adjustment or other interruptions:

The loads for the following periods are the specified percentage of the maximum load rating marked on the tire sidewall:
Time and Percent of rated load
4 hours, 85%
6 hours, 90%
24 hours, 100%

LT Tire: (reference paragraph S6.3.1.2)

“Conduct the test, without interruptions, at the test speed of not less than 120 km/h…” (75 mph)

Inflate a load range E to 60 psi. (410 kPa)

This test uses the same profile as the ST tire.

Immediately following the above sequence perform a Low Inflation Pressure Performance test (reference paragraph S6.4):
This test uses the same tire/wheel as the previous sequence at a reduced pressure.

For a load range E tire the pressure is reduced to 46 psi. (320 kPa)

The same tire/wheel is run an additional 2 hours at the reduced pressure at a speed of 75 mph and 100% of rated load.

Conclusion:

The difference in endurance testing between a ST and LT tire is significant. Both tires are tested through a equivalent loading/time profile. However, the LT tire is tested at this profile at a higher speed (75 vs. 50 mph) and must still endure an additional 2 hour low pressure test without failure. Thus the overall test for the LT is far more rigorous than the ST test.

TESTING - HIGH SPEED PERFORMANCE

ST tire: (reference paragraph S5.5.4)

Load the tire to 88 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
75 mph (121 km/h) for 30 minutes
80 mph (129 km/h) for 30 minutes
85 mph (137 km/h) for 30 minutes

LT Tire: (reference paragraph S6.2.1.2.7)

Load the tire to 85 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
87 mph (140 km/h) for 30 minutes
93 mph (150 km/h) for 30 minutes
99 mph (160 km/h) for 30 minutes

Conclusion:

The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a speed/time profile. The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire. However, the LT tire is tested at significantly higher velocities (nearly 100 mph!) when compared to a ST tire. This is a 16% advantage to the LT tire. Thus, again the overall test for the LT is more rigorous than the ST test.

See, I knew I read it somewhere lol lol ...... So if you are running a ST tire on a trailer the size of a Montana and doing it's max speed rating of 65 mph you are at the edge of failure...... So in my opinion Marathons are junk on a Montana or any heavy 5th wheel. But it is not the tire manufactures fault, I blame Keystone, you get what you pay for. In this case you get a very nice tire that would be good on a 5k lb trailer...but they are putting them on ours....not good.

[mhs4771]

I've had conversation with several Commercial Goodyear Dealers, not your typical Goodyear Store next to the Mall. And they agree that the Marathon is a good lite duty tire for smaller RV, Boat trailer, utility trailers and such, but they have no business being put on heavier RV.
Our SOB originally had a brochure GVWR of 16K, yet the MFR was putting Marathons on as the OEM, they have since reconsidered and are now using the 614s as the OEM.

[Hooker]

quote:Originally posted by mhs4771

I've had conversation with several Commercial Goodyear Dealers, not your typical Goodyear Store next to the Mall. And they agree that the Marathon is a good lite duty tire for smaller RV, Boat trailer, utility trailers and such, but they have no business being put on heavier RV...

Sorry, but that doesn't compute.

If the big tires are maxed out for their ratings and can't carry a 5th wheel, the smaller tires, maxed out for their ratings shouldn't be able to carry that weight.

[mhs4771]

quote:Originally posted by Hooker

Sorry, but that doesn't compute.

If the big tires are maxed out for their ratings and can't carry a 5th wheel, the smaller tires, maxed out for their ratings shouldn't be able to carry that weight.

OK, you totally lost me in your response.
I was strictly talking in reference to the E rated Marathons and their use on smaller RVs, Boat trailers, and utility trailers, you know with GVWRs like less than 10K (no reference to those 10 or 12 inch tires on some small trailers)
These were Goodyear Dealers who dealt with larger vehicles in addition to standard Car/Lite Truck tires.
The Dealer I purchased my 614s from took my Marathons in trade and had them sold in a few days.

[bigskyjimmy]

you lost me too too Hooker I thought Michelle and Ann's response was pretty straight forward and true it did Compute with me

[steelpony5555]

I got 15 inch Marathons on my bike trailer....They have been good even though it does 75 mph ,,,but I think they are rated for 2500 lbs each and I doubt my trailer even with the bike in it weighs more then 2500 lbs, so I got a 2500 lb cushion. I know a lot of bike trailers or box trailers do not have the 16 in tires but a lot have the 15 in tires and usually still have a big cushion. Even TT's below even 10k lbs do not have many problems. Our problem is with the 16 tires there is very little cushion especially with our trailers weighing in at 12k to 15k.

[Hooker]

Let me try again. The tire guy said the Marathons are not okay on larger rigs, but okay on smaller rigs. But, everything is proportional. He said the big tires don't do well with heavy RVs...they are rated to carry that weight but can't carry that weight. It should be the same for the smaller rigs with smaller tires. They should not be able to carry their weight either. However, the smaller tiresd do carry it satisfactorily, so why can't the larger tire carry the heavier weight, since it is rated to carry that weight?

Bottom line, big tires can't carry the weight for which they are rated. Small tires can carry the weight for which they are rated...doesn't make sense.

[steelpony5555]

I think what he was saying and also what I am getting at is even smaller trailers use 15 inch tires. So if you have say a TT that weighs 6000 lbs and you have the 15 inch Marathons that are rated to 2500 lbs, that would mean you have a 4000 lb cushion and that doesn't even take in the hitch weight. Unlike our rigs which I doubt anybody has a 4000 lb cushion. Now that's if my math is correct..lol lol

[scott-pati]

I loved my Marathons, all had 2,000 miles on them and had absolutely no problems with them of any kind. Not sure what all the fuss is, about them???

At 2,001 miles, I bought 5 - G614 tires.

Scott

[mhs4771]

OK, lets try again. My reference to conversations were strictly in relationship to Marathons on Montanas and other large heavy RVs. But using those same tires and putting them on a 10K or less GVWR RV they would be fine as they would only be carrying approx half their load capacity. In other words, using them at half their rating they seemed to work fine, but when they're being used at or very near their max cap they don't seem to hold up.

[mlh]

On a recent trip I talked to several people and saw several campers broke down on the side of the road all had the same problem, tires. All the people I talked to had ST tires. There was one High Country on the side of the road, tire problem. You won't find a ST tire on any thing I own. If you trust them after all that has been reported on this forum, go for it.
Lynwood

[scott-pati]

quote:Originally posted by mhs4771

OK, lets try again. My reference to conversations were strictly in relationship to Marathons on Montanas and other large heavy RVs. But using those same tires and putting them on a 10K or less GVWR RV they would be fine as they would only be carrying approx half their load capacity. In other words, using them at half their rating they seemed to work fine, but when they're being used at or very near their max cap they don't seem to hold up.

I agree with what your saying, I would have no problem with that thinking.

[rohrmann]

We lived the Marathon saga. Purchased our 3402 September 2012, and by December 2013 and with 12,500 miles on the rig, we had 5 Marathons fail. The failures ranged from extremely irregular wear, to what was probably road debris which was our only blow-out, but fortunately did no damage to the rig, to the last failure which was half the perimeter of the tread separated. The only original tire left on the rig was the spare, and all the tires had been maintained to 80 psi and we never exceeded 60 mph. We were east of Tucson at that last incident, and I nursed the trailer the rest of the way to Phoenix where we stayed until we had upgraded to G614's. I attempted to purchase Sailuns, but they were not readily available, which pushed the decision to go with the Goodyear tire. Probably should have done this sooner, but I was determined to give the Marathons a chance. Now we don't have to be constantly watching the rearview mirrors to be checking the tires.

[sambam]

I totally get and agree with what Michelle and Ann are saying. I had these same tires on my sub-10,000lb. Cougar tt. They were trouble-free and I didn't realize the issues until I went up in weight class. The Marathons actually replaced my troublesome Missions.

[TLightning]

I think what Hooker is saying is that using big tires on big rigs and small tires on small rigs is a fair comparison. Both should either hold up or both should fail. But with these tires, the big tires did not hold up, small tires did.

Using a big tire on a small rig is not a fair comparison.

[Irlpguy]

quote:
TESTING - HIGH SPEED PERFORMANCE

ST tire: (reference paragraph S5.5.4)

Load the tire to 88 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
75 mph (121 km/h) for 30 minutes
80 mph (129 km/h) for 30 minutes
85 mph (137 km/h) for 30 minutes

LT Tire: (reference paragraph S6.2.1.2.7)

Load the tire to 85 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
87 mph (140 km/h) for 30 minutes
93 mph (150 km/h) for 30 minutes
99 mph (160 km/h) for 30 minutes

Conclusion:

The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a speed/time profile. The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire. However, the LT tire is tested at significantly higher velocities (nearly 100 mph!) when compared to a ST tire. This is a 16% advantage to the LT tire. Thus, again the overall test for the LT is more rigorous than the ST test.

I would like to know who made the conclusion above noted as well as the other conclusions in this post:

If the information provided is accurate, then the ST tire was tested at 88% of it’s load rating and from the beginning of the test procedure a speed of 10 mph faster than it’s speed rating was used ending in a speed of 20 mph over it’s speed rating .
On the other hand the test was conducted on the LT tire at a somewhat lesser percentage of load rating and all speed/time tests were conducted at under the 103 mph speed rating of the tire.

To test these tires on a equal bases the LT tire would have to be tested above it’s speed rating as was the ST tire, that was not the case, so how does the author of this information make the claim to a 16% advantage to the LT tire. You can manipulate numbers to make your conclusion look plausible but that does not make it fact. Three different people interpreting this information might come up with three different conclusions.

These types of tests are “NOT” conducted to compare one tire designed for one job to a tire designed for a completely different application. They are conducted to ensure the tires meet a standard for the tire application/type being tested.

There is no question that an LT tire will be adequate on lighter Montana’s and other RV’s and will more than likely outlive and outperform the Marathon and many other brands of ST tires. However putting a tire on a 7k axle that reduces the capacity of that axle to the load capacity of the tire makes no sense to me, and many others. That is why we have gone to a G rated tires. The choices for 16” rims are limited and even more so in Canada and for that reason I went with G614’s at a cost considerably more than their cost in the US. I know if I have to replace one I will be able to get them in all but the smallest communities in Canada and the US.

I do not recommend any particular tire brand, I only suggest you know what your rig weighs and purchase tires that have a load rating that is a reasonable amount above what the tires and axles are expected to carry. Saying a particular tire has worked for me for years does not ensure it will work for others because of loading, maintenance, driving habits and other considerations, best to do your own research and be informed.

[steelpony5555]

Sorry the guys links do not work but if you look up the testing on the Federal Motor Carriers Safety Admins site the sections and paragraphs are correct. I am not sure why the guy only included those 2 sections on testing. There are several for both tires. Those are the high speed tests I believe. The only time an ST tire is tested at full weight is at 50 mph for 24 hours which is the endurance test. The LT tire is tested at full weight for 24 hours but at 75 mph. So the ST is at full weight for only 50 mph and the LT is at full weight for 75 mph. But wait it gets better. There is a test where they underinflate an LT tire and test it at full weight at 75 mph for 90 minutes. I found no under inflation test of an ST tire like that. The point the guy was trying to show is that LT tires are put through more rigorous testing then the ST tires. If you take time to look it up and wade thru all the government mumbo jumbo it is clear LT tires are held to a higher standard. But it is just too much info to try and put on here and even where this guy tried to condense it so others can try and follow and to show there is a test standard out there it is a lot. But the numbers there don't lie.....

[Irlpguy]

I certainly do not suggest the testing is not more rigorous on LT tires as opposed to ST tires. I have looked at some of that info before the post was made as well as other information regarding the rules that govern the testing of tires and other parts of automobiles and trucks. I am only saying the tests are not the same because the tires are not only not the same, they are not intended to perform the same work. That is why it is not wise to make comparisons one to the other by using these test methods.

The standard for a passenger/truck tire is more stringent and so it should be, that does not mean the tests done on ST tires are meaningless or that the test requires less of the tire, it is like trying to compare apples and oranges.

The "higher standard" or additional tests performed on LT tires does not suggest they have a built in "reserve capacity". the load capacity of any tire is what the DOT has determined it to be, and is allowed to be stamped on the tire, no more, no less, that is what I am saying.

There will never be a universal agreement by RV owners on tires and the pro's and con's of LT vs ST or offshore vs US made tires. We however should point those seeking advise on the subject to official documents and allow them to make their own decisions based on what their units "actually" weigh and there travel habits. Seldom does anyone seeks this kind of advise when replacing their car or truck tires. Do your own research and don't be overly influenced by all you read in any forum is my suggestion.

[USNSS]

I have a 2012 3100RL with 2000 miles on the Marathons and absolutely no problems, so far. However, based on all the rave reviews the Marathons receive, I called Goodyear customer service to see if they would cut me any deal on some G614s. After giving me a reference number and the number for a local dealer I took the marathons to the local dealer who inspected them and called Goodyear. Long story short, Goodyear allowed $48.62 per marathon for trade in. Dealer then quoted $1240.00 out the door for the 614s after the trade. Still stings a bit for trailer tires, but I told him to get some in. Anyway, Goodyear may be able to help buying new 614s for some folks. Before discussion with Goodyear, the best price I had here in town was $1525.00 for 614s out the door and I kept my Marathons. Maybe could have gotten more for the Marathons on Craigslist, but I'm happy for what its worth.

[Tom S.]

Anyone else notice that the original poster hasn't been back since acknowledging he ran the tires at 65 lbs? No wonder his 'junk tire' failed. Someone also asked how fast he was going, but so far, no answer. Despite where you stand on the Great Marathon debate, this particular issue was user induced, and not the tire's fault.