Tire Failures ONLY on your Airstream?

[Ray Eklund]

We all share the responsibility to maintain our trailer tires... but then, to whose standards?

If you over inflate, the trailer will be under stress and fall apart.

If you under inflate, the tires over heat and can be damaged.

If you go over a certain speed, your tires may fail as they are under inflated or not rated above 60mph.

If you do not use a ST trailer tire, any other tire will fail on those twisting of the axles on dry pavement.

If you... if you... IF YOU... We are all bystanders and yet get conflicting information every day. I have no idea what is true, what is opinion and what might actually WORK.

Right now, the stronger the tire, the more tread... better and safer. Which tire... is best? Only time will tell. I have never had a Michelin tire failure. Never. I would not make this up as there is nothing for me to gain to make any of this up for... any reason.

Stage Coaches in the 19th Century, no doubt, had bad, better and best wagon wheels to choose from. Although, only a few on this Forum are experienced in that area to make comment.

My experience with the 14" Marathon trailer tire was that they were going to KILL ME or someone else. The 15" D Rated Marathon... I do not know as I was not going to find out.

Only we can compare notes. No one else seems to care and will sell to you what they have in stock or can order for you.

Everyone coming forward and debating and talking about our experiences is the only way we can figure out what may be better than other options.

What did owners do before the TRAILER specific tire was available? Used truck rated tires. Or am I too old to have noticed trailers always had a cheap special tire, at a high cost?

[hapsam]

Originally Posted by CapriRacer

I am hoping Roger (Tireman9) will join the conversation.

While I did some legal tire failure analysis, that particular job was done by someone else. He would spend hours looking at a single tire, where I would spend just enough time to see if I could decide if the problem was with the usage or internal to the company.

Having said that, hapsam, my experience is just the opposite of what was reported to you - to the point where I think that either you didn't pickup precisely what he was saying, or that he was a plaintiff's expert, charged with finding a problem so the lawyers would have a case. (Yes, there are people like that in the world!)

My experience in looking at over 10,000 failed tires (I did this for a long time!) was that in less than 10 cases could I find a *defect* that lead to the failure. Further, I saw as many *defects* that SHOULD have caused a failure, but didn't. Even further, I found lots of *defects* that had nothing whatsoever to do with the failure. (If I was that type of guy, I could have become quite wealthy doing plaintiff's expert work by merely pointing to those defects. It's a wonder those so-called plaintiff's experts didn't routinely do that!)

And to the case you pointed out, I, too, have seen stray wires in tires and as I pointed out above, they usually didn't lead to the failure.

And I should point out that I am using the term *defect* to mean something that is there that isn't supposed to be there - or something not there that is supposed to be there.

So what - you may say - was the cause of all these failures that I looked at?

First, many were road hazard related. A puncture or some other kind of road damage.

But the ones I assigned to the fault of the company were typically a design problem. Not enough rubber between the 2 belts, or not a good enough rubber compound in that area. Please note that I could not determine that from an examination, but because of the position I was in, I saw those changes go into place and watched as the problems disappeared.

What photos I have seen of failed trailer tires on this website (and others) persuades me that these failures are no different than what I experienced while working.

I guess I should have been clearer. By default, the particular tire examiner is examining a very small sample of failed tires, mostly from vehicles that were involved in fatal or near fatal accidents in which tire failure was a suspected cause. You can't use this type of data to establish any sort of statistical certainty. I believe what I noted in my initial message was that he said when he found a tire failure it was usually the result of a tread separation caused by some kind of factor internal to the tire. On a separate note, I will say that when we met he had an expanding business but most of his income did not come from testing "failed" tires, but from product testing for other specifications, so don't worry that you missed making a lot of money by becoming a trial "expert".

[Gearheart]

Ray, You mentioned wondering what was used before special trailer tires came along. I remember my best friends dad went moose hunting every fall with a group of 6 guys. they hauled all their gear in a massive box trailer that had 16 inch wheels and 8 bolts per wheel. The tires were from a truck and they were 10 ply. I mentioned that it was a little bit of overkill and was told "Failure is not an option when you are 200 miles from help."

[Ray Eklund]

Gearheart... that is also a reason why trailer tires do not come in colors like yellow, red or blue. They mimic... 'real tires'.

Moose...? In Eastern Wyoming, elk and deer guided areas, some Ranchers in the mountains talk about writing in white chalk 'HORSE'... just in case. I heard they taste the same, but not from personal experience.

Have you ever tied any of those Canadian Trout across the tow vehicle's front hood... and drive up and down Main Street for everyone to see?

I noticed something in older homes we looked at when downsizing. The 3/4 ton truck is too tall to clear the entry. Something to think about for those of you are looking.

The same goes for a RV Garage attached to the house. Airstreams are getting taller. If not for the Air Conditioning vents... the tires add height.

[Tireman9]

Originally Posted by gr.austin

snip
I believe that Michelin is now starting to make a tire that is RV trailer rated in the 15 & 16" ranges.

Happy Streaming

Not sure where you got that info.
You can put a P type tire on a trailer if you de-rate the load capacity
You can put an LT tire on a trailer but do not have to de-rate the load capacity

Would be interested to see where you say a Michelin ST type tire.

[Tireman9]

Originally Posted by CapriRacer

I am hoping Roger (Tireman9) will join the conversation.

While I did some legal tire failure analysis, that particular job was done by someone else. He would spend hours looking at a single tire, where I would spend just enough time to see if I could decide if the problem was with the usage or internal to the company.

Having said that, hapsam, my experience is just the opposite of what was reported to you - to the point where I think that either you didn't pickup precisely what he was saying, or that he was a plaintiff's expert, charged with finding a problem so the lawyers would have a case. (Yes, there are people like that in the world!)

My experience in looking at over 10,000 failed tires (I did this for a long time!) was that in less than 10 cases could I find a *defect* that lead to the failure. Further, I saw as many *defects* that SHOULD have caused a failure, but didn't. Even further, I found lots of *defects* that had nothing whatsoever to do with the failure. (If I was that type of guy, I could have become quite wealthy doing plaintiff's expert work by merely pointing to those defects. It's a wonder those so-called plaintiff's experts didn't routinely do that!)

And to the case you pointed out, I, too, have seen stray wires in tires and as I pointed out above, they usually didn't lead to the failure.

And I should point out that I am using the term *defect* to mean something that is there that isn't supposed to be there - or something not there that is supposed to be there.

So what - you may say - was the cause of all these failures that I looked at?

First, many were road hazard related. A puncture or some other kind of road damage.

But the ones I assigned to the fault of the company were typically a design problem. Not enough rubber between the 2 belts, or not a good enough rubber compound in that area. Please note that I could not determine that from an examination, but because of the position I was in, I saw those changes go into place and watched as the problems disappeared.

What photos I have seen of failed trailer tires on this website (and others) persuades me that these failures are no different than what I experienced while working.

I agree 100% with CapriRacer's post. I also was not involved with legal cases except for one and had to work hard to educate the plaintif's "expert" as his job was to find something he could point at and claim to a jury of non-engineers and non-scientists the thing he was pointing to was the "defect" that caused the failure. I never saw a demonstration or data that confirmed the claimed "cause & effect" relationship the hired gun was claiming.

[Tireman9]

Originally Posted by Ray Eklund

I felt this was a very logical Thread and Post. Man against the elements... type post.

Why so many trailer tire failures and so few, if any, tow vehicle tire failures? You do not need to be an Einstein with a modern computer to figure this one out.

Snip


"

You are correct. The primary reason IMO is staring everyone in the face and the information is molded onto the tire sidewall so you do not need to be an Einstein but almost everyone chooses to ignore the science so they can save a few bucks.

Fact: Tire load capacity is a function of air volume (tire size) and inflation pressure. This is well established and is confirmed by every Load & Inflation chart printed. Increase size or increase pressure and you increase load.

If we all drove around on tires with LT level sizing and inflation there would be almost no failures other than those caused by road hazard or punctures.

BUT
People want softer ride, better fuel economy and lower cost so alternatives were introduced into the market.

LT tires can be considered the standard for tires designed to carry load at highway speeds.

P type tires have a higher load capacity than identical size LT tire but if you check the actual load on most car tires you will see they have 15% to 25% or more "Reserve Load" capacity (more capacity than needed). Inflation is set for cars based not on load but ride, handling and fuel economy. You also know that P tires must have their load capacity de-rated when P tires are used in truck, SUV or trailer application.

ST tires have a higher claimed load capacity than LT tires and TT companies use the smallest (lowest cost) tire that can most of the time meet the specification for load.
How is it that these tires are rated to carry more load?
The load formula for ST tires is based on a 65 mph Max operation speed and an expected shorter life. The formula was developed for bias tires that wore out at less than 15,000 miles.

Since 1990 when ST tires were still "Alpha" sized ( H78-15ST) the load formula has not been changes as far as I can determine.

The science indicates that if you want tire durability on your trailer as you get on your truck maybe you need to consider running the same type tires i.e. LT type and of course that means you also need to use LT Load & Inflation limits.

Here is some info I posted on my blog Sept 14 2011

"Here are some facts from the Tire & Rim Association industry standards book that point out why having all the information is both helpful and important.

P235/75R15 105S (Standard Load -35 psi @ max load)
2028# 35 psi 112mph on a Passenger car
1844# 35 psi 112mph on a SUV or P/U or trailer(no Dual)

LT235/75R15 LRC
1512#single 1377# Dual 50 psi 85mph

ST235/75R15 LRC
2340#single 2040# Dual 50 psi 65mph"

NOTE I did not mention the actual load on a tire but only the specified max. Weight data indicates many TT have one or more tire in overload.

[m.hony]

In my experience, ST tires are inferior and apparently lack some component that makes other tires last more than 3 years.
Also, it seems that the OEM ST tires on most travel trailers are not up to the weight carrying capacity required for the GVWR of the travel trailer.
We had a Forest River Wildwood 28RLSS with Carlisle ST tires that separated within 3 years.
Our Airstream Classic came with Goodyear Marathons that failed within 3 years.
Both times I noticed the tires all pooched out and distended before they exploded and got new tires.
At that point I put 16" wheels and Firestone Transforce HT LT225/75R16 tires on the trailer.
2+ years later and the tires still appear as new.
No more ST tires for me.
I have P-rated tires on my little 3,500# GVWR utility trailer.
I don't like replacing tires every 3 years.
I would rather replace tires every 5, 6, or 7 years.
Have new Michelin tires on my Tundra.
I have gotten 130,000 miles out of a set of Michelins on a Chevy Express van that pulled a 16' 7,000# GVWR cargo trailer the entire time.
That tells me all I need to know about Michelin tires, but...
I don't drive enough any more to ever wear out the tread. The tires will dry rot and the sidewalls will begin to crack long before the tread is worn out, so I get new tires based on dry rot and sidewall cracking rather than miles.
I have some 5 1/2 year old Firestone Destination tires on my old Nissan Pathfinder that still have plenty of tread, but the sidewalls are all cracked up, so I will soon be getting tires.
I seldom ever even have a flat tire.
I have never had a flat repaired on the old Pathfinder in 18 years and I had 1 flat repaired on the Tundra 2 sets of tires back in about 2008 or 2009.
I have never had a flat on the Airstream with LT tires, but I did have a flat on the Wildwood on the ST tires. Luckily I was at a campground when I noticed. I put Fix-a-Flat in it and aired it up and it stayed that way another year till I got new tires...
So, to recap this rambling thread:
St tires- hell to the naw naw to the naw naw naw. Hell naw.
LT tires: Yes!

[Kent M]

This input is NOT to castigate anyone, but rather to compliment every single person who has commented in this thread.

I have sensed NO personal shots from anyone about another's opinion. Every statement has had serious backup, and been well thought out. That's fantastic, and in my opinion totally unexpected.

We need more of this.

I have questions about some of the statements made, but threads of this quality are SUPPOSED to generate questions and and mental agitation. Otherwise, what is their purpose?

My last statement is that I'd really like to meet Ray Eklund. He may not agree, but he sounds like my kinda guy.

Kent
Houston

[Ray Eklund]

Kent, thank you for the kind words and also the thanks to those who have participated in this serious discussion.

Many of us write 'off the cuff' and later find the typos and grammar not aligning. I sometimes wish I could rewrite and clean the flow of some of my posts.

Getting timed out when starting a Thread, does tend to squeeze the review period.

I discovered, the other day, to write on a blank Email page, review it for the tangents and mixing of nouns and subjects that even I do not recognize the thought. When I am happy with it, cut and paste onto the Thread.

A well written post, like the those by our Tire Professionals, takes review and tweaking while developing the post. I also like Switz's methodical posts. These guys are assets. Ideas are fleeting. If you do not get it down on paper right away... it flies off into the vacuum.

[Tireman9]

Originally Posted by m.hony

In my experience, ST tires are inferior and apparently lack some component that makes other tires last more than 3 years.
Also, it seems that the OEM ST tires on most travel trailers are not up to supporting the load.

snip
LT tires: Yes!

Not sure if I agree that all ST tires are inferior. People need to ask themselvewhy one would expect equal performance from two different tires when they force one to carry more load (more deflection & heat) than another tire.

I am inclined to believe that comparable life could be had if two tires of same pricing from any one company were loaded the same, had same speed history and same Interply Shear history.

Tire load capacity is the responsibility of the RV company not the tire company so if there is insufficient capacity or insufficient margin that is the fault of the RV company.

[Action]

Originally Posted by Tireman9

Tire load capacity is the responsibility of the RV company not the tire company so if there is insufficient capacity or insufficient margin that is the fault of the RV company.

RV company installs ST tire(s) that have a total of 500 pounds of load capacity at max pressure above the max designed weight of the trailer. (Which almost never happens in the towing vehicle world)

ST tire experiences a failure ... of any type. Road hazard, low pressure or you name it.

Consumer installs a larger diameter rim, (14 to 15 or 15 to 16 or 16 to who knows what) wheel and a non-ST tire that has load capacity that is far far greater than stock. The conclusion that made is the ST tire is inferior.

Well yeah!! The replacement wheels and tires have so much more extra capacity it takes a lot more to go wrong than the stock arrangement.

Tires are a pain. I don't live my life to tow a trailer I live my life to do the activity the trailer supports. Diligent care of tires both on the TV and the trailer are needed. I have run ST tires on trailers since the ST tire design was created. Inferior tires are usually the ones that don't have enough capacity (based on side wall rating) to start with and are not maintained in my experience.

Have I had a tire failure on an Airstream. Heck Yes!!! Was it an ST tire? Heck yes!!! It was an old set of tires that should have been replaced sooner. I got over the event, first because I had a spare and second because tires on my trailers are not the main focus of RVing and it was my fault for running the tires as long as I did.

>>>>>>>>>>>>>>>Action

[CapriRacer]

The title of this thread is "Tire Failures ONLY on your Airstream." By implication, this means no failures on the tow vehicles. It was started by Ray Ecklund.

I think the point he was trying to make was that there is something wrong with either the trailer or the tires or use or - perhaps - the combination of all 3. And its the last one that I am going to with.

First, the tow vehicle usually isn't loaded to the max 100% of the time. The trailer usually is. The tow vehicle gets used on a regular basis, where the trailer doesn't. There are different types of tires and different brands - and if I want to break it down further, the tire are made in different places.

So here's what I think is wrong: The trailer manufacturer specifies tires that are barely adequate load carrying capacitywise. By contrast, the tow vehicle not only has come under intense scrutiny concerning load carrying capacity - as well as speed rating.

The tow vehicle manufacturers have an excellent feedback system (it's called warrantee), and tires are sort of included in the warrantee system (Long explanation, there!), where the trailer manufacturers don't.

Tow vehicles have a speed limitation built into the vehicle - one that doesn't exceed the published limits of the tires. Not only don't trailers have speed limiters, the speed limitation is so low that it is easy to exceed in normal use - and no one tells the operator about it!

Tow vehicle manufacturers obtain tires directly from the tire manufacturers. Trailer manufacturers get their tires through a distributor and not directly from the tire manufacturer.

And since there isn't a good feedback system in the travel trailer market, the manufacturers assume that any tire they get from their distributor
will work and aren't concerned about tire performance because their warrantee doesn't cover tires.

Ever since the Ford/Firestone thing some 17 years back, the tow vehicle manufacturers have been monitoring tire performance - and since they are in direct contact with the tire manufacturer, they have a good handle on how the tires are performing.

So it shouldn't be any surprise that trailer tires don't perform as well.

But there is good news. Some tire manufacturers have become aware of the shortcoming of trailer tires and have taken steps to improve the situation. My experience says that it takes at least 3 years after the introduction of a durability improvement for it to become apparent. Unfortunately, this improvement is tracked by the ABSENCE of failures, and people response to things that happen not things that don't. It could well be that we are already seeing the improvement, but aren't aware of it simply because there aren't any failures to report.

The bad news is that tires require air pressure to work, so road hazards will continue to cause failed tires, so there will still be some tire failures even if everything else is fixed! It's going to be difficult to discern if an improvement has been made.

[Bill M.]

It is a slow, cold Sat and I read all of this thread. Some of it twice.

My conclusion is that the experts have finally admitted what a lot of us suspected all along. That ST tires are over rated by the manufacture as to actual load capacity and are sometimes not made well.

If you took a 15" Load range C tire with a 1900 lb load capacity at 50 psi and tested it by the same test as for a ST tire what would be the load rating? Or would it fail the test for some other reason?

[Ray Eklund]

I have come to the conclusion that ST tires only good bad when in use.

If you installed ST rated tires tires onto our tow vehicle, would they be derated?

My Airstream is of no value parked at a lot or at home. It is the tires that get me from A to B. Much like... "I do not live to support the Petroleum Industry", so do not buy gasoline.

Gasoline is to our Tow Vehicles, as Tires are to our Trailers. I want the best money can buy, at a reasonable price and feel that I can expect to get where I am going.

Air is the only thing in common, which varies due to elevation and the user has no choice. Tires, everyone has a choice. For better, or worse.

[Tireman9]

Originally Posted by Bill M.

It is a slow, cold Sat and I read all of this thread. Some of it twice.

My conclusion is that the experts have finally admitted what a lot of us suspected all along. That ST tires are over rated by the manufacture as to actual load capacity and are sometimes not made well.

If you took a 15" Load range C tire with a 1900 lb load capacity at 50 psi and tested it by the same test as for a ST tire what would be the load rating? Or would it fail the test for some other reason?

Not sure if I agree that I suggested the ST tire mfg "over-rated" the capacity of the tire or that the tire co made defective products.

The data is well established that a majority of RV have one or more tires in an overload situation when the actual loading is measured.

It is also true that the RV company selects the smallest (lowest load capacity) tire that will meet the requirements. The Requirements state the tire load capacity must be greater than GAWR. Many times the "greater" is less than 10# so there is no margin for error.

While I understand that most do not want to think about their tires, in the RV world, the responsibility for thinking about tires has been shoved off onto the owner by the RV company as they don't want to spend dollar one on doing serious evaluation of tire sizing or on providing the training for new owners. "Detroit" has teams of engineers that evaluate tires and specify the size such that there is probably over 500# to 800# excess load capacity per tire even when the car is fully loaded.

Don't understand your question about testing a LR-C tire to ST test requirements. Test requirements are based on "rated" tire load capacity.
LT testing as with P testing was upgraded in 2002 to more stringent and difficult testing. ST tires are still following the tests developed in the 70's. The RV industry lobbied to not have ST tire test requirements upgraded as they knew they would need to pay more for the tires they put on the RV.

CapriRacer and I (both retired tire engineers) agree that the tires on your RV should have a minimum of 15% reserve load capacity over the MEASURED load for the heavy end of each axle. Not the 0 to -10% or even -15% seen on many RVs. (-10% means an overload)
I believe that using LT type tires with that actual 15% reserve load along with a TPMS would drop RV tire failure rates from their current 5% to 20% to less than 1% and possibly lower.

As the saying goes "Pay me now or Pay me later" Put more expensive tires on or stay with zero or negative reserve load capacity, not get warned of leaking tire and have tire failures and pay later, sometimes a lot more than the cost of a set of tires when you include RV damage and trip delay costs.

[Tireman9]

Originally Posted by Ray Eklund

I have come to the conclusion that ST tires only good bad when in use.

If you installed ST rated tires tires onto our tow vehicle, would they be derated?

My Airstream is of no value parked at a lot or at home. It is the tires that get me from A to B. Much like... "I do not live to support the Petroleum Industry", so do not buy gasoline.

Gasoline is to our Tow Vehicles, as Tires are to our Trailers. I want the best money can buy, at a reasonable price and feel that I can expect to get where I am going.

Air is the only thing in common, which varies due to elevation and the user has no choice. Tires, everyone has a choice. For better, or worse.

Ray, ST type tires are specifically not approved for use on passenger carrying vehicles. Do you think that might signal what RV & Tire companies feel about the margin for ST tires as currently applied by the RV industry?

[Ray Eklund]

Originally Posted by Tireman9

Ray, ST type tires are specifically not approved for use on passenger carrying vehicles. Do you think that might signal what RV & Tire companies feel about the margin for ST tires as currently applied by the RV industry?

******
Many current owners of any brand of trailer, following the Air Forums, now understand a lot more about ST, P and LT rated tires because of TWO professional tire engineers (Tireman and Capri Racer) and Switz.

We are all born ignorant. Some remain so in their entire lives, others question those individuals and learn something in the process.

I have learned to question everything. Not that it is necessary, but I want to understand what I do not know.

"I have come to the conclusion that ST tires only GO bad when in use."
(The edit that was too late to be discovered.)

[Action]

Originally Posted by Tireman9

It is also true that the RV company selects the smallest (lowest load capacity) tire that will meet the requirements. The Requirements state the tire load capacity must be greater than GAWR. Many times the "greater" is less than 10# so there is no margin for error.

This has been my experience in the 1/2 dozen trailers I have owned. Most were boat trailers.

The ST design may have some issues. In my opinion the greater issue is the load capacity of the tire versus the actual towed load. If the ST tire that is installed had the same ratio of capacity versus actual load that passenger vehicle have many would have no issue with ST tires.

The other way to achieve that ratio of capacity versus load is to more to a larger rim diameter which has been followed a lot on this forum. In my opinion that does fix the situation and it is like sending in a F350 to tow a Base Camp.

The solution I have used is to get a higher load capacity trailer tire for the existing rim size. I am good with an ST tire as long as I can get the load capacity I want.

>>>>>>>>>>>Action

[KK4YZ]

Originally Posted by Action

This has been my experience in the 1/2 dozen trailers I have owned. Most were boat trailers.

The ST design may have some issues. In my opinion the greater issue is the load capacity of the tire versus the actual towed load. If the ST tire that is installed had the same ratio of capacity versus actual load that passenger vehicle have many would have no issue with ST tires.

The other way to achieve that ratio of capacity versus load is to more to a larger rim diameter which has been followed a lot on this forum. In my opinion that does fix the situation and it is like sending in a F350 to tow a Base Camp.

The solution I have used is to get a higher load capacity trailer tire for the existing rim size. I am good with an ST tire as long as I can get the load capacity I want.

>>>>>>>>>>>Action

It sure would be nice to have real data on tire failures in towing applications. I’ve heard so much bad news about Goodyear Marathons that I formed the opinion that these tires must suffer from a high level of mfg defects. That the Marathons were produced in China doesn’t help matters at all in my mind.

I have 5 15” GYM’S on my 2017 FC with only 3-4K miles on ‘em and have decided to move to 15” Michelin’s even though on paper the Michelin’s have a lower load capacity....but still more than enough for my 23D. Why? Because the body of experience from other owners seems much more positive with the Michelin LTX tires than with GYM’s.

Am I wasting $$ doing this? Don’t know, but at least I’ll buy myself peace of mind so I can focus on having fun instead of worrying about the tires.