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Old 03-02-2012, 06:03 PM   #1
Seasoned Camper
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M.O.C. #11789
Marathon Scared Straight

Now, with all the negative info on the Marathons, I have some questions.
If the Monty's weight is under the load range of the tires, can I expect them to perform normally?
Or, are the Marathons going to fail under any circumstances.
If I had not read any of these Marathon threads, I'd be sitting here big, dump and happy. Now, you've all got be having jitters. I can't really afford a new set of tires. So, what's a fella to do?

Is there a voice of reason out there?
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Old 03-02-2012, 07:41 PM   #2
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I'm in the same boat. Just getting the new trailer and the bomb threads have me really concerned and not happy that apparently the tires are a known problem. Hate to think after dropping the amount of money for a brand new trailer I am facing another $1000 to replace brand new tires in order to be safe?? All I know is you'd have to look at statistics. Keystone would have a number of "acceptable" failures before they would be concerned with repurcussions. I am wanting to think they do not have enough of a problem with them to pull them altogether. You have to consider how many tens of thousands of people are using these tires and are apparently not having issues. But of course most of the time you only get the negative reports, not all the cases without incident. TPMS is recommended, but even that won't help if it is just an instant failure by blowing out (not a slow leak), unless hopefully you have a temperature change.
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Old 03-02-2012, 07:50 PM   #3
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After reading all the sudden failures, revardless of loading, I only accepted the new coach with G 614 tires, they made the unit 1 inch taller... But the.peace of mind is worth it, btw I got $125 for each tire, changed all 5...
Be very careful...!!!!
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Old 03-02-2012, 11:09 PM   #4
Phil P
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Our Marathons failed the side walls at 3,000 miles add the trip from the factory and you have 4,500 miles. All of this travel was at least 1,000 lbs. below max weight.

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Old 03-03-2012, 01:07 AM   #5
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Here's something that was on another forum a couple of years ago, but it explains pretty well what the problem is with the Marathons:

I have asked many times for someone to explain how a ST tire can be rated to carry more weight than a LT tire in a similar size, without a good answer.

The answer lies in what is called reserve capacity. To quote from Trailer Parts Superstore and this same statement exist on just about every tire site:

'LT' signifies the tire is a "Light Truck/Trailer" series that can be used on trailers that are capable of carrying heavy cargo such as equipment trailers.

If a tire size begins with 'LT' it signifies the tire is a "Light Truck-metric" size that was designed to be used on trailers that are capable of carrying heavy cargo or tow vehicles. Tires branded with the "LT" designation are designed to provide substantial reserve capacity to accept the additional stresses of carrying heavy cargo.

So what is reserve capacity? It is capacity beyond the rating of the tire, capacity that is held in reserve. This reserve capacity comes from the heavy-duty sidewall of the LT type tires. LT's rank at the top of the list when we look at P, ST and LT tires.

Now I finally have an answer to how a ST tire can be rated to carry more weight than a LT tire of similar size.

The ratings of ST tires infringe into the reserve capacity of the tire. This is double bad, because the design of the ST gives us a tire with less reserve capacity to start with as it has a lighter sidewall to start with as most ST tires are much lighter than their LT counterparts.

To quote one tire site:
"Put a different way, the load carrying capacity of an ST tire is 20% greater than an LT tire. Since durability is strictly a long term issue - and the results of a tire failure on a trailer are much less life threatening than on a truck - the folks that set up these load / inflation pressure relationships allow a greater......ah......let's call it load intensity."

There it is in print to be read. They make a calculated decision to give the ST tire a higher load rating because a failure is less life threatening.

I have on a number of occasions pointed out the weight difference between the different tires and have been told that does not matter. Well it does matter. The rubber in the average tire only makes up around 40 some percent of its weight, the rest is in the steel belts, gum strips, steel beads, and the carcass plies. The remaining 60 or so percent of the stuff in a tire is what builds in the reserve capacity.

So to review again, here are some weights:
1. Michelin XPS RIB LT235/85R16 LRE (rated to 3042lbs) Weight 55.41
2. Goodyear G614 LT235/85R16 LRG (rated to 3750lbs) Weight 57.5
3. Bridgestone Duravis R250 LT235/85R16 LRE(rated to 3042lbs) Weight 60
4. BFG Commercial TA LT235/85R16 LRE(rated to 3042lbs) Weight 44.44
5. Uniroyal Laredo HD/H LT235/85R16 LRE(rated to 3042lbs) Weight 44.44
6. GY Marathon ST235/80R16 LRE(rated to 3420lbs) Weight 35.4

So which tires on the list have the most reserve capacity? Well that is not a completely simple answer, as one of the tires is a G rate 110 lb tire and the rest are LRE at 80lb inflation. So if we disregard the G614, then the Michelin XPS RIB and the Bridgestone Duravis R250 due to their all-steel ply construction will have the most reserve capacity inherent in their construction. The twin Commercial TA and Laredo will be next and the Marathon would have little or no reserve capacity available because it was used up in its higher load rating, AND because of it's much lighter construction it had much less inherent reserve capacity to start with.

So what have we learn from this?

I think that the first thing that we learned was that a LT tire can be used at or near it max rated loading without having issues, as they built with "substantial reserve capacity to accept the additional stresses of carrying heavy cargo".

The second thing we may have learned is why ST tires are failing on mid to larger 5th wheels, in that they do not have inherent reserve capacity beyond that rated max loading. Again this is because they have less reserve capacity to start with and their greater "load intensity" used up any reserve capacity that might have been available.

Now, here is an interesting bit of information. I just called Maxxis Tech Line and asked the weights for two tires.

ST235/80R16 LRD 3000 lb rating at 65 lbs of air weights 38.58
ST235/80R16 LRE 3420 lb rating at 80 lbs of air weights 43.43

What??? The Maxxis load range E tire weights almost the same as the Commercial TA?? This is a ST tire that has heavier construction than the GY Marathon at 35.4 lbs. So it has more inherent reserve capacity due to its heavier construction.

Those that claimed its virtues maybe did not know why it was a better ST tire than some of the others, but there it is! It is a heavier built tire with more reserve capacity.

So as one chooses a replacement tire or is asking for an upgrade on a new trailer please get educated on where the reserve capacity exist. Is it inherent in the tire you choose or do you have to factor it into the weight rating of the tire you choose.

Those with heavy trailers that are switching to 17.5 rims and tires rated to 4805 lbs and getting a double injection of reserve capacity, in that they are using a tire with lots of inherent reserve capacity and the tire has much more capacity than the application. It is all starting to make sense.
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Old 03-03-2012, 01:07 AM   #6
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I don't feel warm and fuzzy about the Marathons on my 2012 Montana. And I as you don't feel like putting out another $1000 to correct the problem. But I can see a lot of vendors pointing fingers at each other if something goes wrong.
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Old 03-03-2012, 01:51 AM   #7
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We replaced ours when we got our used/new to us 2009 last year. We where on pins and needles from Florida to Maryland thinking we would have a problem. We each let out a sign of relief when we pulled into the driveway. If right now the tires being new you can get $125.00 each you better jump at the chance. The G14's are the most expensive but there are other options, we got BF Goodrich and are extremely happy with them. Still spent $1000.00. We could not find the G14's under $300.00 each and we would have had to replace our rims also. When we where getting the BF goodrich installed someone came in with a 1 week old tire totally shredded raising heck we glanced over to see the brand, you guessed it Marathan. We knew then we had made the right choice to spend the cash.
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Old 03-03-2012, 03:06 AM   #8
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I agree. Spending $1,000 for new tires on a new rig is outrageous. We were fortunate to have the extra $$ to replace ours. It was worth the $$ to have peace of mind. When I placed a GY Marabomb next to the new Bridgestone Duravis, I could SEE the difference in quality and I'm not even a tire guy. The Marabombs that came on my rig had bulges in the sidewall on 3 of the 4 tires. I took the rig to GY to have them look at them. They said this was acceptable and didn't affect the integrity of the tire. Interesting how the new tires that I purchased had NO blemishes, bulges or other defects. I guess it depends on your level of comfort and whether you consider continuing to roll on the Marabombs an "acceptable risk".
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Old 03-03-2012, 03:27 AM   #9
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I guess one thing to ask yourself is how are you going to use your trailer? Short trips in your area or long hauls on interstates and highways. If you are just weekend camping,I would say to just watch your tires for any signs of damage. I know you can't be 100% sure on that but at least some piece of mind. If you are planning a long haul and will be away from home for a while,most of the people here can give you some good advice on replacements as they have learned from experiance.My feeling is you have to look at your situation and go from there. I have been one of the lucky ones that had Carlisle's on when we bought it,but I also do not travel long distance and I watch for any clues that may be there,like sidewall bulging or hi heat at a rest stop. "thats my story and i'm sticking to it"
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Old 03-03-2012, 03:44 AM   #10
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Good post. We would not have the OEM tires on the regular 3402 Montana and would have insisted on the G614's or no sell. We put on a lot of freeway miles. We are now going with the Big Sky package that includes the G614's. If you do the numbers between the regular 3402 and the Big Sky package the B.S package is a g ood value.
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Old 03-03-2012, 04:39 AM   #11
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Chinese tires...pay a little now to replace or pay a lot later for repairs plus new tires! I SPEAK FROM EXPERIENCE.
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Old 03-03-2012, 04:48 AM   #12
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My adviced: Get rid of them. I had issues with my 2010 after 4500 miles.
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Old 03-03-2012, 07:27 AM   #13
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I just sent Goodyear an email about the marathons. They might not do anything but I will have their email to keep on file.
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Old 03-03-2012, 08:29 AM   #14
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Bout made up my mind that I'm going out and buy five new 16" 5750# steel rims cause I don't want to pay the $104.00 plus shipping each for five new Tredit 3750# wheels and then go the G614 route. My wheels are rated at 3500#s which places me between a rock and a hard spot when it comes to getting non china bombs.
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Old 03-03-2012, 09:05 AM   #15
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I had Mission Bombs on my new Montana when I purchased it back in '06, until I had a failure within two years while on trip. At that time, I replaced them with Goodyear Marathons because I had heard they were the ST tires of choice for trailers. Then I joined the MOC and learned that higher gross trailer weights make Marathons very suspect and many Montana owners now referred to these as bombs. Oops, too late!! If I swapped out all my brand new Marathons right afterwards, DW would have killed me because of the cost and miscalculation. The old safety versus cost issue, but I've compromised.

I think with being overly careful with my Marathons I can maintain safety and wait out the 5 years until I will be replacing my tires with probably Maxxis STs.

We just don't use our trailer enough to swap tires out that much. We are also very fortunate that the trailer sitting in my driveway constantly reminds me to keep its tires inflated to the correct psi which is what I do (tires lose air by nature, so adding about 5 psi each time doesn't surprise me) every month or so. For now, it's still short trips (under 600 miles) each time and I do not exceed the 65 mph rating on the tires and staying under its axle weights for all tires. They are also covered when on the driveway. I also swing wide on turns slow down for bumps and examine tires frequently during travel so I feel confident that if these bombs are going to explode, I can catch it. DW is happy with that so far and it's working too. I couldn't have been this cautious if it wasn't for the MOC and other RV forums where this is a frequent topic.

So far so good and in the 4th year into the Marathons, they are still holding up quite well.
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Old 03-03-2012, 11:18 AM   #16
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I can understand your decision and while I do not want to give the impression that I am being supportive, here is some food for thought. This forum and the "other" forums are primarily reporting instances of failures associated with many items. You never see nor hear of the reports that do not result in failures. Therefore, there is no way to determine the true failure rate of the tires or any other items that are supplied on ours and others rigs. I would assure you, that if this failure rate was documented and reported, that there would be well publicized recalls. I can only infer that the failure rate is "acceptable" since no recall has occurred. This may make you feel a little better, but do not take it as a message that can give you a false sense of security. Keep an eye on the inside of the tires as well since it seems that is where some of the "bubble" failures occur and I would think are not noticed which can lead to total failure, keep an eye on the tread closely as well. All decisions are personal, I made our personal decision and I respect yours. You are correct in the sense that inflation, speed, and pressure monitoring are key items. The other thing that can help is to not put the tires into "binds" in sharp turns and tight spots. Utilize pull-thru sites, etc. Good luck and here is hoping that you will be one of the ones who do not have to contribute to the failure rate!
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Old 03-04-2012, 01:32 PM   #17
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I have not used Marathon tires sence 2002 I have been putting LT tires on my Terry, and Montana trailers ever sence. also my Monty came from the factory with LT 16 inch tires on it. I did have to replace one due to a blister on the side wall so I replace all 4.
so far so good there 2 years old and still look good.
Pulling a 2004, 2980 RL an oldie but goodie.
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Old 03-05-2012, 03:22 PM   #18
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You could be one of the lucky ones that doesn't have a problem with the tires. Be vigelint and check your tire pressure daily before you start out for that day. I would add a TPMS to your coach at about $200 and keep your speed around 60mph or under until your ready to replace them. The TPMS will give you some piece of mind.
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Old 03-06-2012, 03:23 AM   #19
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My rules of the road:
  • Check pressure every time you pull
  • Check side walls and tread for any irregularities
  • Drive 60 MPH or less
This has been my protocol from the beginning. I am not saying this is the perfect way of RVing. Do what you wish. We are full timers, so we put many miles on our rig and have covered 45 of the 48 contiguous states and parts of eastern and western Canada.

My 2003 Big Sky had General tires. Two of them failed, one on each side, causing over $5,000 damage to the coach. I caught the other two in failure before they actually blew out. I replaced the "E" rated tires with "G" rated tires made in China. Same result, tread separation and failure.

When we traded for our 2008 Big sky, I used the OEM Missions for about 3,000 miles and replaced them with Goodyear G614 tires. I also added a tire pressure monitoring system. The TPMS won't keep you from tire failure, but if you do, It may keep you from beating the side of your rig up with a blown tire. On our blowouts, we did not hear it or feel it.

Now I am four years and many miles down the road, having crossed the USA several times. The G614 tires look good with no crazing on the sidewalls and even wear on the tread. The way my rig is loaded, I run them at 105 psi from a cold start.

Did I want to spend the extra money for the G614 tires? No! Am I sorry I did? NO!! Since I carry a higher deductible on my insurance, I figure I have come out about even on the cost and am way ahead on the confidence and peace of mind. That's my experience. Do what seems best for you.
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