Tireman9
Akron, OH
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JBarca wrote:I had asked about tire cracks before and did not get a definitive answer on what is tolerable and what is not. Today when I had all 4 tires off and I looked real good at them.
Here is one from the right side. This is not the problem bulging tire in the reply above. I am starting to get fine side wall cracks and a few splits in the tread.
Here is the DOT date
snisnip 2108
Some of the side wall cracks. They are real fine at this point but at the 4 year mark they are showing up.
The cracks seem to still be small
snip
close up
These tread "cracks" look to me more like cuts with some of the steel belts being exposed to water and rust.
When does one start getting concerned about these and start a change out? I was hoping for 5 years but don't know any more.
Any thoughts on when to start the change out process?
Thanks
John
Removed some of the pictures to save post space. The tread cuts would be the biggest concern so far as I believe the steel is starting to rust. I can see small areas of deposit around the cuts and what looks like a broken steel filament. This will just get bigger and you need to keep an eye on the tread area for any signs of distortion or non uniform curvature.
Tou might consider replaceing the two worst tires this year and the other two next year to spread the cost.
You can learn more if you visit my tire blog RVTireSafety
In my opinion as a QS9000 and ISO/TS 16949 Quality auditor the word "Quality" does not appear to be in the RV industry dictionary.
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Tireman9
Akron, OH
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JBarca
Excellent job of providing the data needed to make an informed suggetion with all the measurement data and pictures. You didn't identify if it was the one with the tread cuts or not. I am a bit surprised to see all the tires growing such round treads given they are radials. If you look at the passenger or LT type tires on other vehicles you will probably not see such rounding.
The Big OC tire would be on my replace now list.
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Tireman9
Akron, OH
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FastEagle wrote:A question for our experts:
There have been numerous failures from day one with the ground-up LT235/85R16G tires designed for trailer service. They are almost exclusively used on 7000# axles and should have the load capacity to live out their expected life expectancy but are falling short of it. The leading manufacturer has made at least one major attempt at resolving the problem with limited success.
What do you guys think about that steel cased tire? I’ve wondered about it’s regrooveability feature. Even though it has shallow threads it still has the extra tread depth to allow regrooving. Is that presenting a heat problem when the tire is near it’s operational limits? Do you think regrooving them early would help in extending their life expectancy?
FastEagle
I covered Retread and Regroove in my blog.
The heat comes from the area at the edge of the steel belts so cutting parts of the tread will not reduce the amount of rubber between the tread surface and the belts. Also regroving will leave microscopic cuts in the base of the cuts which could lead to accelerated cut growth.
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FastEagle
Taylors, SC
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Tireman9 wrote:FastEagle wrote:A question for our experts:
There have been numerous failures from day one with the ground-up LT235/85R16G tires designed for trailer service. They are almost exclusively used on 7000# axles and should have the load capacity to live out their expected life expectancy but are falling short of it. The leading manufacturer has made at least one major attempt at resolving the problem with limited success.
What do you guys think about that steel cased tire? I’ve wondered about it’s regrooveability feature. Even though it has shallow threads it still has the extra tread depth to allow regrooving. Is that presenting a heat problem when the tire is near it’s operational limits? Do you think regrooving them early would help in extending their life expectancy?
FastEagle
I covered Retread and Regroove in my blog.
The heat comes from the area at the edge of the steel belts so cutting parts of the tread will not reduce the amount of rubber between the tread surface and the belts. Also regroving will leave microscopic cuts in the base of the cuts which could lead to accelerated cut growth.
I can't see that you answered anything I asked.
FE
Dickinson, ND
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winkyb
Florida
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John
I think I would change them all.We had one on a 2011 trailer that the tread started to swell.I found it when I pulled into a camp ground.we were not that far from home on that trip so put the spare on before we headed home.When I took it off the rim and looked a it the inside lining had a wrinkle in it like the whole tire had swelled and had stretched the inter liner.I had always replaced the China may pops when I bought a trailer until this one and the wife was on my case about putting new tires on less than a year old trailer and I thought maybe I am making to much out of it.But this proved me wrong.Tires were built in Aug 2010.
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winkyb
Florida
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John
I think I would change them all.We had one on a 2011 trailer that the tread started to swell.I found it when I pulled into a camp ground.we were not that far from home on that trip so put the spare on before we headed home.When I took it off the rim and looked a it the inside lining had a wrinkle in it like the whole tire had swelled and had stretched the inter liner.I had always replaced the China may pops when I bought a trailer until this one and the wife was on my case about putting new tires on less than a year old trailer and I thought maybe I am making to much out of it.But this proved me wrong.Tires were built in Aug 2010
There is a RV trailer here at Daytona now sitting on the side of I 95 with the fender well riped up so bad that I think the guy took his stuff out of it and just left it there.
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CapriRacer
Somewhere in the US
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JBarca wrote:I have 2 tire issues that just surfaced today. Since we have the tire tech folks here see if you can point me in the right direction of the problem. I do not yet have a blow out and I'm trying to keep it that way. ......
- Axle weight scaled at 7,660# with no water. When I fill the fresh tank over the front axle it adds 266 # more axle load.
........
- Tire DOT date is 2908. Tires installed 3-28-09
.........
- I have weighed the left and right side of the camper. The slide side (left) is approx 350 # heavier.
.............
OK thoughts? Something is not right with this tire and my gut tells me get ride of it now, put the unused spare (bought same time) on and buy a new tire for the spare. It will be a Maxxis ST as Denman is no longer.
I would like to learn what went wrong or what I did to cause this.
I have my own tire machine and will demount the tire for inside inspection when the new spare comes in.
Thanks
John
I'll post the 2nd question in the next reply. It has to do with cracks in the other tires.
John,
I think you have a "rubber to steel cord adhesion failure" - kind of rare. Cause? Kind of hard to do at a distance. The cuts MIGHT have something to do with it, but we would need to connect the cuts to localized areas of separation.
The only thing that bothers me about this diagnosis - aside from not being able to see the tire in person - is that normally, steel belt adehsion failures also result in the tread being distorted relative to the casing - kind of twisted look. Does this tire have nylon cap plies? (Look at the sidewall and see what it says for construction)
My advice would be to replace all the tires unless you can definitively connect the cuts with the separation.
***************************************
I am also going to take issue with your math - AND EVERYONE PAY ATTENTION!! I have seen others do this type of math and I think there is a hidden pot hole there.
The principle is that for tire loading you want the absolute WORST loading. The load an individual tire experiences is NOT the average. Tires don't average out the load and neither should you.
First you said the axle loads were 7660, but added that the water tank adds 266# more axle load. Why didn't you add that to the axle loads? Why did you use the 7660# for your calculation as is when you already know the side to side loading is different? What about the front to rear loading difference?
OK, so I'm going divide the axle loading by 4 to get 1915#. Add 133# for the water = 2048. I estimate that there is a 15% variation in loading by wheel position, so the worst case is 2409# - and I recommend a 15% reserve, so the tire should be capable of 2834#
That mean an ST225/75R15 Load Range D is about 12% under that value.
I'd recommend going up to a Load Range E and 80 psi as the inflation pressure.
* This post was
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edited 04/23/12 03:47am by CapriRacer *
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CapriRacer
Visit my web site: www.BarrysTireTech.com
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CapriRacer
Somewhere in the US
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FastEagle wrote:A question for our experts:
There have been numerous failures from day one with the ground-up LT235/85R16G tires designed for trailer service. They are almost exclusively used on 7000# axles and should have the load capacity to live out their expected life expectancy but are falling short of it. The leading manufacturer has made at least one major attempt at resolving the problem with limited success.
What do you guys think about that steel cased tire? I’ve wondered about it’s regrooveability feature. Even though it has shallow threads it still has the extra tread depth to allow regrooving. Is that presenting a heat problem when the tire is near it’s operational limits? Do you think regrooving them early would help in extending their life expectancy?
FastEagle
FE,
I know you don't think Roger answered your question in his blog - but he did, just not directly.
No, the regrooving feature doesn't add much in the way of heat to the party. Steel casing tires are already quite thick and that additional tread thickness is small by comparison.
Like Roger, I also think that the problem for RV tires is time not wear. Regrooveable tires would be fine for a truck that would wear out a tire in 6 months, but has little value when it takes many years.
So, no, I don't think regrooving a tire would extend its useful life in trailer service.
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CapriRacer
Somewhere in the US
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JBarca wrote:I had asked about tire cracks before and did not get a definitive answer on what is tolerable and what is not. Today when I had all 4 tires off and I looked real good at them..........
When does one start getting concerned about these and start a change out? I was hoping for 5 years but don't know any more.
Any thoughts on when to start the change out process?
Thanks
John
John,
I agree with Roger that the photos are of cuts, not cracks. I disagree that I see steel cord there, but YOU are in the best position to judge that.
I am assembling some photos of cracks so I can explain the borderrline between acceptable and unacceptable. It's a little complex as it matters where the cracks are, as well as there are different causes of cracks and they should be treated differently.
I'll bet that you - like a lot of people - are looking for a simple, easy to remember, covers all the bases, rule (singular) for cracks and unfortunately, it isn't that simple.
My simple rule would be - go to a tire dealer.
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Tireman9
Akron, OH
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winkyb wrote:John
I think I would change them all.We had one on a 2011 trailer that the tread started to swell.I found it when I pulled into a camp ground.we were not that far from home on that trip so put the spare on before we headed home.When I took it off the rim and looked a it the inside lining had a wrinkle in it like the whole tire had swelled and had stretched the inter liner.I had always replaced the China may pops when I bought a trailer until this one and the wife was on my case about putting new tires on less than a year old trailer and I thought maybe I am making to much out of it.But this proved me wrong.Tires were built in Aug 2010
There is a RV trailer here at Daytona now sitting on the side of I 95 with the fender well riped up so bad that I think the guy took his stuff out of it and just left it there.
Your tire that had a "wrinkle" on the inside and started to "swell" on the outside is a perfect candidate for filing a complaint with NHTSA. I have previously posted a list of the info NHTSA is looking for and if you add the "swell" and the "wrinkle" pictures it would be hard for them to ignore once there were a couple of other complaints from the same tire plant that also involve what we think is a structural detachment.
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