Goodyear Marathon Tires

[Ins. Man]

Where do I find the manufactured date on my tires and if the tread looks good etc. at what point do I need to replace them due to age?
Thanks

[ROBERT CROSS]

Tire Tech Information - Determining the Age of a Tire

[reddogfox]

On my US made Marathon's it is marked on the inside as mounted, so you have to crawl under the trailer to read the manufacture date.

[Turtle]

More information here: Tire Tech Information - Tire Aging – Part #1

[chaimemet]

on our trip to NS & PEI the first day out the tread completely blew off the Marathon. Used for less than 2 years at least every 6 weeks. Changed all 4 to Carlisle Es 10 ply.

[Gene]

There are many threads on Marathons, tire age, and such. Try these:

http://www.airforums.com/forums/f438...old-54644.html

http://www.airforums.com/forums/f438...ice-52955.html

http://www.airforums.com/forums/f438...ons-54985.html

This is probably more than you wanted to know. There's a very long Marathon thread I couldn't find.

Date of manufacture may be on the inside or outside depending how they were mounted.

Gene

[Airslide]

Originally Posted by chaimemet

on our trip to NS & PEI the first day out the tread completely blew off the Marathon. Used for less than 2 years at least every 6 weeks. Changed all 4 to Carlisle Es 10 ply.

I too am running the Carlisle E's but I only inflate them to 65 cold vs the 80 recommended. Once hot the pressure is up to 70psi (100* outside temp at 60 mph sustained.)

I know there are concerns that the E rated tires will beat the trailer to death but according to my weight there is two thousand pounds on each tire.

I will keep reporting on them.

Thanks Vin

[dznf0g]

Airslide, how are the Carlisles holding up after the 2010 season?

Just curious, I will be needing tires by next spring.

[SteveH]

Originally Posted by Airslide

I too am running the Carlisle E's but I only inflate them to 65 cold vs the 80 recommended. Once hot the pressure is up to 70psi (100* outside temp at 60 mph sustained.)

I know there are concerns that the E rated tires will beat the trailer to death but according to my weight there is two thousand pounds on each tire.

I will keep reporting on them.

Thanks Vin

Don't know how old they were, but I have a friend who is in our WBCCI unit that has had two blowouts on Carlisle E rated ST tires this year on his 34 footer. I don't believe they are the panacia that some folks believe.

[Airslide]

Hi,

Not sure how others are finding the quality but after a couple seasons on these Carlisle's I'm very happy. The wear pattern is completely even and there are no bubbles on the sidewalls. I run the tire pressure at 65psi and check them before and after each trip. So far so good. Im also very careful to not pinch the sidewall when coming down my driveway or out on the road. Once the sidewall is compromised and air is allowed to tranfer into the outer ply I think its just a matter of time before a blow out.

Vinnie

[dznf0g]

Thanks, slide. My 30' of course, isn't quite as heavy as yours, but I asked because after digesting virtually ALL of the posts and reading other material, as well as going door to door to the tire shops, I have come to the conclusion that LRE at 65PSI is where I want to go. Still kind of waffling on brand. Probably Carlisle or Maxxis.

[Wingeezer]

Originally Posted by dznf0g

Thanks, slide. My 30' of course, isn't quite as heavy as yours, but I asked because after digesting virtually ALL of the posts and reading other material, as well as going door to door to the tire shops, I have come to the conclusion that LRE at 65PSI is where I want to go. Still kind of waffling on brand. Probably Carlisle or Maxxis.

I'm in exactly the same situation as you - I hope to change my five year old Marathons for Maxxis E rated if I can get them when we are in Tucson this winter.

My fall back position if I cannot get Maxxis will be Carlisle E's I guess, although I'm a bit concerned that when I did a search for reviews of Carlisle trailer tires on the internet (not on this forum) I seemed to be reading mostly bad news.

I have heard a little about a brand called Towmaster, but don't know much about them and how readily available they are.

In any event, I plan to go with E rated on our 2005 Classic 30.

Brian

[dznf0g]

Airslide
your post about the 65psi and rising to 70psi @ 100 is encouraging. I found this article this morning which puts to rest the pressure issue for me. It looks at determining your cold pressure by trial and error by monitoring pressure rise while traveling. With TPMS this process would be much easier.

You're right in that 10% rise range at 65PSI cold.

The Vintage Airstream Life » Blog Archive » Determining Ideal Tire Pressure

The only thing I think I would add to the article is a calculated factor for ambient temp. rise. With TPMS it's probably not an issue since you can readily determine when tire temp stabilizes. (I have found tht's between 1 - 2 hours of driving). Since tire pressure rises approx. 1 degree for every 10 degrees of (ambient) temp rise, if you take a reading at 6AM at 60 degrees and wait till 2PM to take another reading at 100 degrees you'll be off by about 4 degrees in your calculations.

I know this doesn't make much sense untill you read the article, but Slide seems to be right in that sweet spot for temp/pressure vs. ride quality. This answere a lot for me.

[2airishuman]

the notion of "dialing UP" tire inflation pressures has been around a long time.

in fact we've addressed it HERE in the forums dozens of times over the years...

as an example see post #22 from this 2005 thread...

http://www.airforums.com/forums/f438...tml#post197695

it's an old school approach and CAN work, but takes a LOT of tinkering.

really there is no valid reasons to follow that approach in modern daze.

IF planning to use ANY PRESSURE less than the max/sidewall for ST tires...
__________

weigh the rig.

start with pressures based on one of the manufacturer tables...

keep in mind these tables are NOT recommended inflation guides.

ADD 5-10 psi if planning to drive OVER 65 mph (not to exceed sidewall pressure ratings)...

and be done with it.
_______

IF using a tpms that provides temps, one can fiddle a lot more.

but be advised that south side tires will run 10-20 degrees higher in daytimes...

and tires with HIGHER loads will run hotter.

or tires with ANY brake, bearing, hub issues may run hotter.

and so on,

there are lots of reasons for variations that will BEFUDDLE tinkering with warm tire inflations.
_______

the old "dial it UP" wisdom for adding air during travel was really intended for passenger cars/tires...

and from the earliest days of radial tire use

when LOOKING at the sidewall bulge was confusing compared to bias ply tires.

cheers
2air'

[Gene]

Originally Posted by dznf0g

Since tire pressure rises approx. 1 degree for every 10 degrees of (ambient) temp rise, if you take a reading at 6AM at 60 degrees and wait till 2PM to take another reading at 100 degrees you'll be off by about 4 degrees in your calculations.

I think you mean 1 lb./10 degrees. I question that number that because direct sun on the tires makes them hotter because they are black. I find the tires in the sun before I go anywhere are about 3 to 4 lbs. higher (this sentence makes me wonder why tires aren't spelled "tigher") than the tires in the shady side. I seem to remember someone once posted the pressure increases more than 1 lb./10 degrees, but that was a couple of years ago and I don't know where it was posted.

Cold pressure is what you are supposed to fill the tires at—before driving—but the position of the sun and the time of day changes things. Here in the southwest we often have 40˚ swings in temp during the day and 65 lbs at dawn (maybe 40˚, 75˚ or more in the afternoon) may be somewhat higher before driving, and tires on the south side while driving may be 10 lbs. or more higher than starting out. Driving south or north or up or down in altitude may mean significant swings in ambient temps. Some early mornings we have 68 lbs. in Load Range E tires and be up to 81 lbs. by afternoon. This means my TPMS monitor starts beeping and red lights come on—I check the pressure, cancel the warning, and keep driving. Then another tire does the same thing and so do I. When I do stop, I let a pound or two out of the tire. My TPMS reads 3 lbs. differently than my hand held pressure gauge and about 2 lbs. difference with the gauge on the compressor.

I err on the side or more pressure rather than less since the wheels and tires can take it better than the tires take lower pressure. This means using the shady side as the norm, doing it before the sun starts to warm up the air and the tires, and using the gauge that reads lowest. After looking at weight tables for my tires and the weight on each wheel, 68 lbs. early morning cold pressure seems to be the right spot.

There are so many variables that while it's good to be perfect, perfection as always is elusive.

After reading what feels like a gazillion tire posts on a thousand tire threads it's hard not to start screaming. Just about every brand ST tire has been criticized. It's been said Carlisles were once good, but cheapened. I think Towmaster was also criticized as being whatever they could get from China. Maxxis owners have had some problems and it's been said they are presently backordered. It's been said Marathons are now made in China, but are all made in the US, or maybe Canada. And all ST tires have been criticized as having low standards. While Tire Rack has ratings of tires on its website, last time I looked, did not rate ST tires. Whenever the subject of ST tires comes up at campgrounds or at tire shops, everyone seems to agree ST tires are junk. Of course, there's been plenty of criticism of LT tires.

Gene

[dznf0g]

Gene,
you're correct about the sun thing. I am just pointing out the article makes sense in theory and I was assuming all equal temps in the morning. (ie. shortly after sunup before any "artificial heating" by the sun) Or at night, just before bedtime. My observation is that sunny side is worth about 2 - 3 PSI additional rise in my northern climate in summer. This has to be taken into account with your measurements throughout the day of travel as well. I would ignore a high pressure alarm on the sunny side if the shady side is within that 10% bogey. (but watch the numerical readout in case there is a bearing or brake issue which keeps the pressure rising) My Doran high pressure alarm comes in at 25% above my preset. That means at 65PSI, I would have to be at 81 PSI to get an alarm. I think that's more than a sun effect, or normal tire heating. Or does it mean that LREs run at 65 PSI heat up MORE than LRDs at 65 PSI? Or, in your "vertical" area, are you getting a lot of brake heating? It may also be different down south. I've heard of wild temp swings from night to day in the desert, but don't have much experience there. Up here we get, maybe a 25 degree swing from night to day in summer on average.

Yes, it was supposed to be 1lb/10 degrees....sometime the brain runs faster than the fingers on the keyboard.
I have studied TPMS on TVs and cars an I am comfortable that 1lb/10degrees is pretty close. However, I have also noticed that my Marathons seem to be a little more than that. Hmmmm...could something in their construction make them heat more than other tires. They are the only brand that I have had with TPMS, so I don't know.

Wow, I have never seen the type of rise that you have experienced. I run at 65 PSI cold, and the highest I have ever seen is 72 PSI at about 85 - 90 degrees ambient, and 7640 lbs (per scales) on the axles. (LRD tires). At these temps. I see only about a 4 PSI rise on the TV.

I'm not saying, this is the answer. Just saying that it makes sense and I am going to experiment with it next spring. I may have one more trip before I retire the Marathons and go to LREs.

One of the points of the article was the "counter intuitiveness" of letting out air for a "hot tire". I'm not saying it's true at this point, but the author states that's just opposite of the right thing to do.

[dznf0g]

2Air,

I missed your post due to the page break. As usual, I find little to disagree with in your comments. That being said, I'm not sure that the "old school" approach is expired with whatever changes have taken place with tire technology. There is something we're all missing in this "ball of yarn". Yes, there are some substandard tires out there, but it can't be all brands, and all STs. Various posts on various forums would indicate that is the case. I've never had a blow out in 35 years of towing. Did throw a chunk of tread once on a too old tire in my inexperienced youth.

I just can't get to the place that LREs should be run at sidewall pressures on a trailer prescribed to have LRDs at 65 PSI (or arguably lower), for fear of beating the trailer up. (of course at 7640 lb combined axle weight for 4 tires in my case). Most everyone agrees that there is an imperceptible difference in sidewall flexibility between a LRE and an LRD, but a 15 psi difference will make a huge difference in primary shock absorption.

We can demonstrate this by taking our unloaded car or light truck and running it down a rough road at the door jamb recommended pressure and then filling to sidewall max, and feel the difference. I know that's elementary, but again, we're missing something in many of these tire failure accounts.

However, since so many of us are now equipped with TPMS, it might be time for some data gathering?

[r carl]

Originally Posted by Airslide

Hi,

Not sure how others are finding the quality but after a couple seasons on these Carlisle's I'm very happy. The wear pattern is completely even and there are no bubbles on the sidewalls. I run the tire pressure at 65psi and check them before and after each trip. So far so good.
Vinnie

Putting #80 in your tires is like towing with a 1 ton.

[Wingeezer]

Originally Posted by r carl

Putting #80 in your tires is like towing with a 1 ton.

Not sure about that - seems to me I have read that it is your trailer's primary suspension that mainly determines the sort of ride your trailer will get and that the effect of the tires is minimal.

Can anyone shed light?

Brian

[2airishuman]

i agree passenger/truck tires can ride very differently with just a few psi of change.

and while p/lt tires are capable of handling the max sidewall pressure...

VEHICLE makers specify tire pressures very specifically in oem sizes, typically well below max psi.

trailer axles and tires aren't placed at the perimeter and don't deal with slip angles, cornering or traction issues that motor vehicles do.

Originally Posted by dznf0g

...I just can't get to the place that LREs should be run at sidewall pressures on a trailer prescribed to have LRDs at 65 PSI (or arguably lower), for fear of beating the trailer up. (of course at 7640 lb combined axle weight for 4 tires in my case). Most everyone agrees that there is an imperceptible difference in sidewall flexibility between a LRE and an LRD, but a 15 psi difference will make a huge difference in primary shock absorption...

the 'advantage' if there is any, with sticking to ST tires is that they come in 3 flavors based on expected LOAD.

C D and E are distinctions that matter and should be considered carefully.

on a rig like vin's 30 slide which is the heaviest stream on 4 wheels, there is some logic in choosing Ez over Dz.

but for the most part sticking 2 the a/s oem size/rating/inflation is straight forward/clear/sensible.

a trailer spec'd with Cz (inflated to 50 psi) is NOT improved by going to Ez run at 50 psi.

the same is true for the majority of modern units with oem Dz run at 65 psi.

the notion of Ez somehow being better or an UPgrade is baseless in almost all trailer situations.

Ez do not have more ply or more layers of rubber/belts.

the sidewalls appear equally supple in D and E rated versions before mounting.

they are built to handle HIGHER air pressure thereby supporting higher loads.

but running them at significantly lower pressures (40-55 psi) negates the higher load capacity and introduces negatives...

more sidewall/belt flex, more side wall motion, less stability (resistance to sway), more heat, altered contact patch and so on...

in the a/s world, it is best to stick with the factory spec'd tire rating (and inflations) in almost all situations.

heavy trailers, folks who wanna tow OVER 65 mph or folks towing in desert HEAT...

are a few examples where E rated may be useful.

and those folks need to understand they are trading ride quality (softness) for other features (speed, less heat, more load bearing)

my experience with ST tires (canadian and chinese and thai') has been good (documented in another thread)

the tires have all performed as expected and with proper attention to the basics.

failures do happen

but separating out the failures based on inherent tire defects

from the 1000s of failed valve stems, underinflated, abused, old tires, and is problematic.

add to that the country of origin hate/bashing, and the repetitive negative posting by a small # of people,

and selecting new tires becomes overly complex.

cheers
2air'