(BTW I am aware of the various "issues" concerning Carlisles, Marathons, and ST vs LT, having read many tire threads here over the years. Moving right along then-- :)My 2002 built OEM Goodyear Marathons (marked made in Canada) have just been replaced with Carlisles (marked made in China) built in 2014, and I have noted some differences in their "plies" as marked on the tires. Perhaps some of the experts here can explain it all. Thanks.Both are ST225/75R15 "For Trailer service only" The Marathons are Load range C and the Carlisles are Load range D. They show the weight ratings 2150 at 50psi and 2540 at 65psi, so that is clear.If it matters, here is another set of markings:Marathons- C11L DOT PDHH MROR 2602Carlisles- AQ29 DOT AQHH 2114Now the plies as marked on the tires: Marathons- Tread 5 plies 2 Poly cord + 2 steel cord + 1 nylon cordSidewall 2 plies poly cordCarlisle RH- Tread 4 plies 2 poly + 2 steel Sidewall 2 plies polyIn the recent thread about Carlisle RHs ISTR it was posted that they have a nylon cap or whatever, unlike the older Carlisles, but I am unclear on that. If they have nylon now, why isn't that marked like on the Marathons?Here is the Carlisle blurb on that. Mine are the Duratrail technology Radial Trail RHhttp://www.carlisletransportationproducts.com/product/tires/trailers-toy-haulers-towablesOK different topic, but I don't want two threads. For weight carrying, I only need Cs at 50 PSI, but now I have these Ds carrying the same weights. I know my truck tires have "adjustable" PSIs based on the load they carry up to a max rating.What about the STs? Do I pump the Ds to 65 or go with something less since they will not be "loaded" fully? Thanks.

In the recent thread about Carlisle RHs ISTR it was posted that they have a nylon cap or whatever, unlike the older Carlisles, but I am unclear on that. If they have nylon now, why isn't that marked like on the Marathons? Carlisle sells 5 different ST tires according to their website. Sport Trail LH Radial Trail RH Sport Trail Ultra Sport Radial USA Trail are you sure your tires say Carlisle Radial Trail RH ? OK different topic, but I don't want two threads. For weight carrying, I only need Cs at 50 PSI, but now I have these Ds carrying the same weights. I know my truck tires have "adjustable" PSIs based on the load they carry up to a max rating.What about the STs? Do I pump the Ds to 65 or go with something less since they will not be "loaded" fully? Thanks. you have two things going here. 1. The advantage of the D tire comes only at those higher pressures. 2. Carlisle says;-Maintain air pressure at the maximum PSI recommended on the tire sidewall. The Warranty is void if the tire or wheel fails due to damage from improper inflation pressures, exceeding the maximum speed limit, or overloading the tire beyond the maximum load capacity stated on the sidewall. Protect that new tire warranty and run them at 65 psi if the wheels are rated for those higher pressures.

Thanks guys. Ok I will run them at 65 lbs even though they will not be "worked" to that level of weight carrying. I was worried about the middle of the tread wearing from "over-inflation" and maybe the trailer being bounced too much back there.Yes, I have the "Radial Trail RH" tires and the "plies" are as marked on the tire is as stated in the OP. The 12 year old Marathons lasted this long because they were mostly out of the sun and only had about 10K miles on them. However they did have a couple of flats from nails/screws and one with a sharp rock that needed a patch, so one of those repaired ones sort of disintegrated the other day. People were passing me beeping and pointing, so that was my clue! Pieces of tire going from my trailer as seen from the driver's side mirror! Luckily I got to a road-side turn off spot before the wheel rim was damaged. Saved by Good Sam since I didn't feel like changing the tire with my spare (which I could have with a lot of work) and I have paid up to Good Sam over the years so I thought I would just get some of my money's worth. :) (Thanks, Mill Bay Towing) Anyway, after that little episode, I got all new tires figuring my luck had run out on those old ones! (Instead of getting just one new one) It turned out that local shops' availability and prices left me no choice but these Carlisles. (at KalTire) I figure I can ignore the usual "issues" on that brand because of the low mileage they will ever get.

BFL13 wrote:Thanks guys. Ok I will run them at 65 lbs even though they will not be "worked" to that level of weight carrying. I was worried about the middle of the tread wearing from "over-inflation" and maybe the trailer being bounced too much back there.Yes, I have the "Radial Trail RH" tires and the "plies" are as marked on the tire is as stated in the OP. The 12 year old Marathons lasted this long because they were mostly out of the sun and only had about 10K miles on them. However they did have a couple of flats from nails/screws and one with a sharp rock that needed a patch, so one of those repaired ones sort of disintegrated the other day. People were passing me beeping and pointing, so that was my clue! Pieces of tire going from my trailer as seen from the driver's side mirror! Luckily I got to a road-side turn off spot before the wheel rim was damaged. Saved by Good Sam since I didn't feel like changing the tire with my spare (which I could have with a lot of work) and I have paid up to Good Sam over the years so I thought I would just get some of my money's worth. :) (Thanks, Mill Bay Towing) Anyway, after that little episode, I got all new tires figuring my luck had run out on those old ones! (Instead of getting just one new one) It turned out that local shops' availability and prices left me no choice but these Carlisles. (at KalTire) I figure I can ignore the usual "issues" on that brand because of the low mileage they will ever get.At this point there are not any issues on the NEW Carlisle RH. FYI-The old tires were Carlisle Radial Trail. The NEW tires are signified by the "RH" designation after the name. The tread design is similar too. They improved the tire but did not purchase new molds for the new design. If you go here it looks like subtle tread pattern differences-ClickySome of the images are of the old tire-some are the NEW tire.

Thanks. Mine say on the sidewall markings that they have "Duratrail Technology" and are RH, so no doubt they are the best ever! :) Anyway I wonder about the "4 plies" instead of the "5 plies" for the tread like on the old Marathons (Never mind that being Load Range D, everybody calls them "8 ply" :) ) Of course then there is "belts" vs "plies" Way too complicated!

ST Tire "Plies" Question and a PSI Question | Good Sam Community

BFL13
Explorer II
Mar 06, 2015
Retired Admiral "Bull" Halsey joined the board of Carlisle Tire and Rubber Company of Pennsylvania at the end of 1946. If Carlisle was good enough for him, it is good enough for me! :)
RinconVTR
Explorer
Mar 06, 2015
Me Again wrote:
Yep, same company has this in their warrant document!

Best Practices
– Any tire, no matter how well constructed, may fail when in use
because of punctures, impact damage, improper inflation,
overloading, or other conditions resulting from use, misuse
or neglect.
– High speed towing in hot conditions degrades tires significantly.
– Best practice. Do not exceed 60 mph while towing a trailer.
– Most ST trailer tires have a maximum speed rating of 65 mph.
– Load carrying capacity decreases as heat and stress generated by
higher speed increases.
– Time and the elements weaken a trailer tire.
– 3 to 5 years is the average life expectancy of a trailer tire,
regardless of mileage.
– It is estimated that in approximately three years, roughly
one-third of a tire's strength is gone.
– After three years, depending upon storage and conditions of
usage, consider replacing trailer tires even if they have tread
depth remaining.
– After five years, trailer tires should be replaced in all cases.

These are exactly as you state..."best practices".

They are not related to their warranty or any tire ratings.
Me_Again
Explorer III
Mar 04, 2015
Yep, same company has this in their warrant document!

Best Practices
– Any tire, no matter how well constructed, may fail when in use
because of punctures, impact damage, improper inflation,
overloading, or other conditions resulting from use, misuse
or neglect.
– High speed towing in hot conditions degrades tires significantly.
– Best practice. Do not exceed 60 mph while towing a trailer.
– Most ST trailer tires have a maximum speed rating of 65 mph.
– Load carrying capacity decreases as heat and stress generated by
higher speed increases.
– Time and the elements weaken a trailer tire.
– 3 to 5 years is the average life expectancy of a trailer tire,
regardless of mileage.
– It is estimated that in approximately three years, roughly
one-third of a tire's strength is gone.
– After three years, depending upon storage and conditions of
usage, consider replacing trailer tires even if they have tread
depth remaining.
– After five years, trailer tires should be replaced in all cases.
RinconVTR
Explorer
Mar 04, 2015
BFL13
Explorer II
Mar 03, 2015
laknox wrote:
BFL13 wrote:
(snipped)

OK, so what happens when one tire on one side goes flat? The other tire has to take that one side's whole weight. Does not mean for sure that is one half, because the two on that side might not be the same. Usually they would be the same of course.
(snipped)

Not necessarily. The equalizer between the axles allows the wheel with the flat to drop to the ground, so it's still carrying weight, almost the full weight as if it was not flat, so it should =not= overload the same-side tire on the other axle. If this weren't so, then every time you went over a speed bump in a campground, you'd overload each tire as you went over the bump. If a tire company is telling you that you need to replace the other tire due to an "overload", that's just so they can sell you another tire, and laugh all the way to the bank, IMO.

Lyle

I did note after getting parked off the road, that while the shredded tire was on the ground (rim almost was, but enough tire remained so the rim was not damaged), the other tire that side was "showing" it had more weight on it than usual by being bulged at the bottom somewhat.

I suppose that means it was holding up more weight than usual but not necessarily double the normal weight as indicated above with the equalizer.

So the situation could depend on how long you had to go at what speed on that one tire before you could get off the road as to how much damage was done to the other tire. Just more to toss into the total mix of circumstances while figuring what to do.
laknox
Nomad
Mar 03, 2015
gitane59 wrote:
Me Again wrote:
Again, we have had numerous reports of the second tire on the same side fail within limited miles of the first one!!!!!!!! Chris

Hey Chris seems like pretty simple math to me. With a FW you have three points of contact. The Pin and the 2 pair of tires on each side.
For simply ballpark numbers lets say the pin has 2K lbs and each pairs of tires on each side of the travel has 5K Lbs for a total trailer weight or 12K lbs.
The single weight of 5K lbs is distributed in a un-equal but similar manner between the 2 tires on each side of the trailer. So for argument sake lets say the distribution is equal at 2500 lbs on each tires as you are running down the road. and lets say that the tires have a 3042lb max capacity.
Each tire has a 500lb cushion under normal conditions.
Lets says one of those 2 tires blows out and can't carry any weight?? Where does that extra weight go?
Almost entirely to the other tire on that same side. So now you have a tire rated for 3042 lbs trying to support 5K lbs. 60% Overloaded.
We all know how fast heat builds up in a under-inflated well there will be a rapid heat build up in that suddenly overloaded tire as well regardless of inflation level, speed traveled or distance covered.
How far and how fast it must carry the 60% over load will depend on how quick it fails and how much deterioration towards failure it will incur.
Regardless of whether it fails or not before the blown tire is replaced it's life will have been severely impacted and will fail prematurely compared to an identical tire under the same conditions except for the sudden 60% overloaded.
Not changing the second tire on a side when ones blows out seems foolish to me.

So, you're saying that the rim on the flat tire does not touch the ground at all, when the tire goes flat? Not in my experience.

Lyle
laknox
Nomad
Mar 03, 2015
Sport45 wrote:
wilber1 wrote:
Totally agree. Standard practice in aviation is if one tire fails, the other tire on the same axle is also changed.

Axles on aircraft are short, stubby things if they have an axle at all. (Could be just a bearing spindle on each side of the framework, I don't know.) Anyway, I can see a failed aircraft tire significantly increasing the load on the opposite tire. This would be similar to a flat on a dual increasing the load on it's mate.

Does a tire failure on a trailer significantly impact the loading of the tire on the other end of the axle? I expect most, if not all the load is transferred to the tire that's on the same side. In fact, when that end of the axle drops it might actually unload the tire on the other end a bit.

And most aircraft with multiple tires on a landing gear carry about 10 to 20 times more weight per tire than our RV tires, so, YES, you have to replace the other tires on a bogie when one goes down. FWIW, EACH TIRE on a 747-8I carries 54,833+ lbs on it at its gross takeoff weight of 987,000 lbs. That's the equivalent of 16 E-rated ST tires at each position of its 18 tires. :-)

Lyle
laknox
Nomad
Mar 03, 2015
BFL13 wrote:
(snipped)

OK, so what happens when one tire on one side goes flat? The other tire has to take that one side's whole weight. Does not mean for sure that is one half, because the two on that side might not be the same. Usually they would be the same of course.
(snipped)

Not necessarily. The equalizer between the axles allows the wheel with the flat to drop to the ground, so it's still carrying weight, almost the full weight as if it was not flat, so it should =not= overload the same-side tire on the other axle. If this weren't so, then every time you went over a speed bump in a campground, you'd overload each tire as you went over the bump. If a tire company is telling you that you need to replace the other tire due to an "overload", that's just so they can sell you another tire, and laugh all the way to the bank, IMO.

Lyle
BFL13
Explorer II
Mar 03, 2015
Me Again wrote:
Again, we have had numerous reports of the second tire on the same side fail within limited miles of the first one!!!!!!!! Chris

When my tire actually shredded this time I replaced them all. Being 12 years old, I figured another one would go soon and my time on these had run out. (in fact I went too long as that proved)

However, if I had a puncture on one much newer set of tires, I would just get that fixed and keep the other tires as is. So it depends on what kind of shape and age the other tire is before I would buy two "just in case"

I have had a few punctures but never had one shred like that before. I think any tire good or bad quality can get a puncture, but if one of a newer set of tires shredded I would wonder about the others true quality.

Perhaps that is what some of these different opinions turn on where people are not talking about exactly the same thing, hard to tell. Nobody is a crazy risk-taker here so it is all about situations.

If you did buy two, I suppose they should both go on the same axle and the two older ones would be on the other axle so that would mean a shuffle. The spare would already be on where the punctured one was.
My spare is the old ugly wheel so it has to go back as the spare but if the spare wheel looks like the others it could stay there as part of the shuffle. You would have to draw yourself diagrams to get it all figured out what to tell the garage you want! :)

In my case the spare was previously patched (cut by a sharp rock type of puncture, not just a nail hole) and chosen to be the new spare back then, so I had that tire tossed and the best of the three other old ones is now the spare on the ugly wheel.
gitane59
Explorer III
Mar 03, 2015
Me Again wrote:
Again, we have had numerous reports of the second tire on the same side fail within limited miles of the first one!!!!!!!! Chris

Hey Chris seems like pretty simple math to me. With a FW you have three points of contact. The Pin and the 2 pair of tires on each side.
For simply ballpark numbers lets say the pin has 2K lbs and each pairs of tires on each side of the travel has 5K Lbs for a total trailer weight or 12K lbs.
The single weight of 5K lbs is distributed in a un-equal but similar manner between the 2 tires on each side of the trailer. So for argument sake lets say the distribution is equal at 2500 lbs on each tires as you are running down the road. and lets say that the tires have a 3042lb max capacity.
Each tire has a 500lb cushion under normal conditions.
Lets says one of those 2 tires blows out and can't carry any weight?? Where does that extra weight go?
Almost entirely to the other tire on that same side. So now you have a tire rated for 3042 lbs trying to support 5K lbs. 60% Overloaded.
We all know how fast heat builds up in a under-inflated well there will be a rapid heat build up in that suddenly overloaded tire as well regardless of inflation level, speed traveled or distance covered.
How far and how fast it must carry the 60% over load will depend on how quick it fails and how much deterioration towards failure it will incur.
Regardless of whether it fails or not before the blown tire is replaced it's life will have been severely impacted and will fail prematurely compared to an identical tire under the same conditions except for the sudden 60% overloaded.
Not changing the second tire on a side when ones blows out seems foolish to me.

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