Tires

[dalemonroe]

We had tread separation on one of our original equipment tires. The trailer has 22k miles on it. The tires are Goodyear Marathons on 14 inch rims. Each wheel carries under 1600 pounds and the tires are rated at 1860. One morning in Winnemucca Nevada, I noticed that one tire had rounded tread like a motorcycle tire. I put on the spare. I also noticed that the tire on the other side was worn out. I expected longer life. The Goodyears on my van also were short lived. After arriving home, I discovered that 14 inch trailer tires only come in a C load rating as were the originals. I bought some Kumho Tires which were D rated, over 2100 pounds. These are a slightly different size, 205R x 14 instead of 215/75R 14. They stand about 1/8 inch taller. They are not ST (trailer) rated but since my trailer has a single axel, the tires don't experience the extreme side forces of a tandem axel trailer.

[BlackAces]

Special Trailer (ST) tires are not mileage tires. Some of their manufacturers quite frequently advertise their maximum life expectancy at 20K miles. Of course that will depend on how well they are maintained and the loads they normally carry

[CapriRacer]

Originally Posted by dalemonroe

We had tread separation on one of our original equipment tires. The trailer has 22k miles on it. The tires are Goodyear Marathons on 14 inch rims. Each wheel carries under 1600 pounds and the tires are rated at 1860. One morning in Winnemucca Nevada, I noticed that one tire had rounded tread like a motorcycle tire. I put on the spare. I also noticed that the tire on the other side was worn out. I expected longer life. The Goodyears on my van also were short lived. After arriving home, I discovered that 14 inch trailer tires only come in a C load rating as were the originals. I bought some Kumho Tires which were D rated, over 2100 pounds. These are a slightly different size, 205R x 14 instead of 215/75R 14. They stand about 1/8 inch taller. They are not ST (trailer) rated but since my trailer has a single axel, the tires don't experience the extreme side forces of a tandem axel trailer.

It's not exactly clear, but it sounds like:

You took off ST215/75R14 Load Range C Goodyear Marathon's (Max load 1870# @ 50 psi, 26.7" diameter) and replaced them with 205R14C's Load Range D (Max load 2271# @ 65 psi 27.0" diameter) Kumho Radial 857's

You didn't tell us how old the GY's were.

You also didn't tell us if you inflated the new tires to 65 psi. If you didn't, you aren't getting the full load carrying capacity listed for the tire.

Oh, and these tires a C type tires - the European equivalent of LT tires. The tire size is suitable for trailer use - and this specific tire is designed for trailer use ONLY.

[slowmover]

Age, not mileage, is the reason to replace TT tires (as few of us will ever run enough miles in roughly 5-years . . less time in some climates, maybe a bit more in others with highest quality tires).

[Ahab]

Mine were gone at 10k. I'm surprised you got 20.

[dalemonroe]

The GY's were factory installed on our 2008 Safari. We just replaced them two weeks ago.

[dalemonroe]

A trusted friend who was a career tire man at Bridgestone told us that the the age of a tire is irrelevant unless you see cracking in the sidewall.

[BAB]

I wonder how many posts exist on AirForums on TIRE issues. There must be thousands. This much smoke over this many years surely indicates that there are "issues" with trailer tires on our Airstreams. I refuse to believe that it's solely because of owner ignorance or abuse. While I don't frighten easily, what I read here caused me to pull off brand new 15" wheels and tires and replace them with 16" wheels and Michelin's. Having just completed a 6,300 mile trip, I watched them carefully (I opted for installing a TPMS as well). There were times I hit 70 MPH (not often, but it happened). I did mountains. I had a full load of stuff....once in awhile even a full water tank and 1/2 in gray and black tanks. At no time did my tires overheat or did I see a pressure rise of more than 7 pounds. While I cut corners on some stuff (like buying huge quantities at COSTCO), anything that remotely looks like a SAFETY issue with my A/S gets top priority. Tires and other running gear top that list. It would be interesting to have a validated study on GYM's and their safety/suitability.

[CapriRacer]

Originally Posted by dalemonroe

A trusted friend who was a career tire man at Bridgestone told us that the the age of a tire is irrelevant unless you see cracking in the sidewall.

Well your trusted tireman shouldn't be trusted any more.

While cracks in tires indicate a tire's condition, lack of cracks does not. That's because cracks are the result of both the material properties AND the amount of flexing that has taken place. Poor material properties with little flexing can result in little cracking - and that's where age comes in.

There isn't a total agreement among tire manufacturers, but my take is that this is highly dependent on where you live. If you live in hot climates - for example AZ, CA, NV, TX, and FL - the age limit is 6 years, and if you live in a cold climate - MN, MI, WI, MT, and ND - the limit is 10 years. States in between are uh ....Mmmmm.... in between.

[dkottum]

Originally Posted by BAB

I wonder how many posts exist on AirForums on TIRE issues. There must be thousands. This much smoke over this many years surely indicates that there are "issues" with trailer tires on our Airstreams. I refuse to believe that it's solely because of owner ignorance or abuse. While I don't frighten easily, what I read here caused me to pull off brand new 15" wheels and tires and replace them with 16" wheels and Michelin's. Having just completed a 6,300 mile trip, I watched them carefully (I opted for installing a TPMS as well). There were times I hit 70 MPH (not often, but it happened). I did mountains. I had a full load of stuff....once in awhile even a full water tank and 1/2 in gray and black tanks. At no time did my tires overheat or did I see a pressure rise of more than 7 pounds. While I cut corners on some stuff (like buying huge quantities at COSTCO), anything that remotely looks like a SAFETY issue with my A/S gets top priority. Tires and other running gear top that list. It would be interesting to have a validated study on GYM's and their safety/suitability.

I agree tires are not the place to skimp. The problems with a blown tire in the middle of nowhere at night or on a busy interstate, or the damage it can do, is too great a headache.

We also added 16"wheels/Michelins and just returned from a 6,000 mile trip. Checked them at each stop, never a problem. I've gained some peace of mind with them that I did not have with the GYM's.

doug k

[dalemonroe]

Originally Posted by CapriRacer

Well your trusted tireman shouldn't be trusted any more.

While cracks in tires indicate a tire's condition, lack of cracks does not. That's because cracks are the result of both the material properties AND the amount of flexing that has taken place. Poor material properties with little flexing can result in little cracking - and that's where age comes in.

There isn't a total agreement among tire manufacturers, but my take is that this is highly dependent on where you live. If you live in hot climates - for example AZ, CA, NV, TX, and FL - the age limit is 6 years, and if you live in a cold climate - MN, MI, WI, MT, and ND - the limit is 10 years. States in between are uh ....Mmmmm.... in between.

Are you quoting a materials scientist? What are the sources of your assumptions? I've never discarded a tire till the tread has worn out. If what you are saying is true, you'd think I would have had a blow out at some time in my 48 years of driving. I haven't. It's just wrong to throw away something that is still useful.

[CapriRacer]

Originally Posted by dalemonroe

Are you quoting a materials scientist? What are the sources of your assumptions? I've never discarded a tire till the tread has worn out. If what you are saying is true, you'd think I would have had a blow out at some time in my 48 years of driving. I haven't. It's just wrong to throw away something that is still useful.

I'm a tire engineer with a major tire manufacturer. I've been in a lot of different areas, but the current one is in the warranty end of things. One of my duties is answering questions from dealers and consumers - like this one.

Tire age comes up a lot and while there is quite a bit of information out there, because of differences in locale, personal experiences vary a lot.

The problem here is about risk. A tire failure can result in some fairly severe consequences - and even though tire failures are rare, it is much better to avoid that single incidence rather than be on the bad end of a statistic.