Tire Problems? Some Facts from a Tire Engineer

mattpopp

Trouble Maker
Huh, learned something new. Guess I should have googled it.


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Sandpirate69

Well-known member
Mattpop, I guess you learned something knew. I too run 17.5 Goodyear g114 @ 120psi. Left side was torn up by a Tomax. Scared wife & daughters, replaced all 5 rims & tires. No more problems.

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dave10a

Well-known member
This is incorrect. it is the O2 that "leaks" out - ie permeates the rubber. The O2 molecule is a bit smaller in size than N2. Do not confuse molecular weight with molecular size.

http://www.getnitrogen.org/pdf/graham.pdf
You basically correct as I recall from my chemistry class days. However, with the modern rubber compounds leaking has been minimized. I filled two tires with nitrogen and left the other two with normal air to see the results from travel. I expect minimal difference because nitrogen expands 3% less than oxygen and since normal air has about 20% oxygen the expansion is even less for atmospheric air. My monitoring results did not detect any difference in running temperature and pressure. Also the static pressure in all tires are the same as when I filled them a year ago at 70 deg. So the results of my non-scientific test show that filling nitrogen is a complete waste of money--- albeit it only cost me $10 per tire to fill and they cycled the filling process three times to get over 98% nitrogen in the tires. Maybe I'll try helium next :angel:
 

brianharrison

Well-known member
So the results of my non-scientific test show that filling nitrogen is a complete waste of money--- albeit it only cost me $10 per tire to fill and they cycled the filling process three times to get over 98% nitrogen in the tires. Maybe I'll try helium next :angel:

I would agree that paying extra for N2 is not a value add step in the operation of consumer products. It is a money grab IMHO. Where precise pressures or other demanding applications (ie aircraft) is paramount, it certainly seems to be beneficial (I do not have any experience in this arena).

Moisture free supply would be the other benefit where water vapor/condensation may create issues (rim corrosion, or pressure fluctuations due to evaporation/condensation).

By the way - I use air and desiccant dryers on my compressor). I even top up my free N2 filled tires with air!

Brian.
 

tireman9

Well-known member
Tireman,

When mine blew. The thread came off. Then the tire blew. I know this because the trailer felt like I ran over a small car and then it was follow by an loud explosion.
Trailer was less then a few months old with approx 1000 miles on it. I was about 40 or 50 miles from the house. Before leaving I had just checked the tires air pressure. This was a Cyclone but for the most part the trailer was empty with the exception of about 200 lbs worth of personal items in it.
Because of reading all of the horror stories before that happened I was terrified to drive over 60mph. Now that I have 17.5's with a tire rating well beyond what the trailer can handle and a speed rating of 75mph. I exploit that every chance I can get. It's a good feeling when you have a few ounces of confidence in your tires.
You can only assume that the trailer was delivered with proper tire inflation.
But one thing you have to assume. Is that people that have trailer tire failures caused by the end user. You would think they treat all of their tires the same. Including their TV and any other personal vehicles that they have. It seems that they would or could see the same possible failures across their personal fleet. That's in the aspect that they would report those tire failures as well.
If they don't and most cases of tire failures on this forum and any other Trailer based forum are only related to ST tires. The trend seems that ST tires are just poor quality tires. Not made to the same spec and quality as of passenger tires.
I guess my argument is why aren't we seeing several TV tire failures as well if we want to blame the end user for not properly caring/using his tires? Or blaming it on a road hazard. Because most of your conclusions are suggesting that most cases are caused by mis use. Just seems like there should be alot of TV tire failures as well if that is true.
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Couple of items to respond to.
Since the vast majority of TT come with ST type tires wouldn't you expect the vast majority of failures to be on ST type tires?
Also since most if not all ST tires are made in China wouldn't you expect most if not all ST tire failures to be of tires made in China?

Have you ever wondered why RV refrigerators built in Indiana are so bad? Could it be the bad workers and poor design of Indiana manufacturers? Or could it just possibly be because the primary supplier of RV refrigerators is located in Indiana?

Correlation is not proof of cause. This is something you learn when you study statistics and product failure analysis.
Remember every person in jail has eaten MiccyD fries therefore eating MickyD fries makes you a criminal.

Now to your question of why TT tires fail at higher rate than TV tires. I would suggest a couple of reasons. I know from data that over half of TT have one or more tires in overload. I know from data that TV and personal vehicles have a much lower % in overload. We all see a significant % of TT running above the speed rating of the ST tires for miles on end but I doubt we have witnessed many TV exceeding the 99 or higher mph speed rating of TV tires even for a short distance.

Finally there is a scientific reason for identical tires run at identical load and speed to fail at a higher rate when applied to TT. This has to do with the unique side loading whenever any turning is done. A TV suspension allows all 4 tires to turn and "point" to the center of the radius. However I have never seen or heard of a multi axle TT having dynamic steering so there is always at least one tire being dragged around every corner or turn. This force results in 24% higher Interply Shear. This is the force that is trying to tear the belt and tread apart. If you were to eliminate all the overloading and underinflation from TT applications, you still would have a higher failure rate because of this Interply Shear.

Hope this answers your questions and corrects some of your assumptions.
 

kowAlski631

Well-known member
There is actually a big difference between assumptions & facts. Despite our adherence to weight, speed, & tire pressure & monitoring, we also blew - yes blew - one tire. Defect, who knows as there was not enough left of the tire to determine.

I'm sure we all can understand your allegiance to the tires you helped create, however we have experienced first hand the results of tire failure.

Martha
 

mattpopp

Trouble Maker
Couple of items to respond to.
Since the vast majority of TT come with ST type tires wouldn't you expect the vast majority of failures to be on ST type tires?
Also since most if not all ST tires are made in China wouldn't you expect most if not all ST tire failures to be of tires made in China?

Have you ever wondered why RV refrigerators built in Indiana are so bad? Could it be the bad workers and poor design of Indiana manufacturers? Or could it just possibly be because the primary supplier of RV refrigerators is located in Indiana?

Correlation is not proof of cause. This is something you learn when you study statistics and product failure analysis.
Remember every person in jail has eaten MiccyD fries therefore eating MickyD fries makes you a criminal.

Now to your question of why TT tires fail at higher rate than TV tires. I would suggest a couple of reasons. I know from data that over half of TT have one or more tires in overload. I know from data that TV and personal vehicles have a much lower % in overload. We all see a significant % of TT running above the speed rating of the ST tires for miles on end but I doubt we have witnessed many TV exceeding the 99 or higher mph speed rating of TV tires even for a short distance.

Finally there is a scientific reason for identical tires run at identical load and speed to fail at a higher rate when applied to TT. This has to do with the unique side loading whenever any turning is done. A TV suspension allows all 4 tires to turn and "point" to the center of the radius. However I have never seen or heard of a multi axle TT having dynamic steering so there is always at least one tire being dragged around every corner or turn. This force results in 24% higher Interply Shear. This is the force that is trying to tear the belt and tread apart. If you were to eliminate all the overloading and underinflation from TT applications, you still would have a higher failure rate because of this Interply Shear.

Hope this answers your questions and corrects some of your assumptions.

Unfortunately it doesn't. But to address some of this. There are quite of few SRW pickups out there towing Toy Haulers. In reality there is very few 5th wheel toy haulers that meet the lower weight requirements for a SRW. But yet there is a ton out there towing them. So Statistical speaking I would say the majority of those SRW are over weight while towing.

Far as the Tandem axle trailer or even worst a triple axle trailer scrubbing and preloading the side walls when turning. It shouldn't matter one bit. Tire manufactures know this will happen and they expect it to happen. These tires will be designed to handle that type of impact on them. Well it happens on DRW pickups as well. It also happens on Semi's in a much worst way. So this theory is irrelevant.

But what you have done is built a stronger argument that ST tires are the wrong choice for trailers. That's been may argument the whole time.


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danemayer

Well-known member
There's no reason to think that tireman9 or any other tire engineers who write on this subject work for Towmax or have allegiance to any other particular type or brand of tire.
 

mattpopp

Trouble Maker
There's no reason to think that tireman9 or any other tire engineers who write on this subject work for Towmax or have allegiance to any other particular type or brand of tire.

Is this you being sarcastic? Cause it sounds like you are taking a jab at tireman9.


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danemayer

Well-known member
Is this you being sarcastic? Cause it sounds like you are taking a jab at tireman9.


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Nope. Not taking a jab or being sarcastic. I think their information is based on scientific method and engineering principles.
 

whp4262

Well-known member
Not sure about the bearing wear. However, the tire temperature of 50 deg F above ambient is about right according to the Valor tire monitor company. That s tihe inside casing temperature and not the tread temperature. Racing tire get near 200 deg on the tread and aircraft tire get near the same. That's one reason, I believe, racing and air craft use nitrogen instead of normal air the small amount of oxygen in normal air can cause a fire (rapid oxidation) while nitrogen does not. Axel alignment turns out to be a bigger problem than I thought for RV trailers-- especially with some trailers having an uneven weight distribution because of slides and/or poor engineering/layout to please the layout demands of the public. Any tires is a big topic with a lot of bias out there. BTY I experimented with nitrogen and found it a waste of money for normal pickup and RV applications-- the effects turned out to be negligible as I would expect.

Fire is one reason for using Nitrogen in aircraft tires but the main reason is that air can have a much higher water content than Nitrogen. At altitude the water will freeze so most aircraft operated at higher altitudes will have Nitrogen in the tires and most of the aircraft operated at lower altitudes will just have air in the tires. Nitrogen is also recommended for landing gear strut inflation because the lack of moisture helps to prevent corrosion in the struts.
 

mattpopp

Trouble Maker
Fire is one reason for using Nitrogen in aircraft tires but the main reason is that air can have a much higher water content than Nitrogen. At altitude the water will freeze so most aircraft operated at higher altitudes will have Nitrogen in the tires and most of the aircraft operated at lower altitudes will just have air in the tires. Nitrogen is also recommended for landing gear strut inflation because the lack of moisture helps to prevent corrosion in the struts.

Actually airplanes use Nitrogen in there tires because of the instant extreme temperature changes when landing. Having oxygen in the tires when they heat up so quickly could prove to be lethal.

It's recommend that every type of accumulator be charged with Nitrogen. Pretty much every shock or strut on the road or air is charged with nitrogen.


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mattpopp

Trouble Maker
Nope. Not taking a jab or being sarcastic. I think their information is based on scientific method and engineering principles.

Hum, Statistics and assumptions really isn't scientific method or a type of engineering principles. Though his ability to look at a failed tire to suggest how it failed is pretty impressive.


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caissiel

Senior Member
I used LT's tires rated at 1950 lbs for 7 years over inflated by 20% on our previous 5th wheel unit axles rated at 5000 pounds. I solved failing properly rated ST tires. I figured that trailer tires are designed for ease of towing with reduced rubber on the thread part of the tire. Any road debris will ruin the ST tire. While the LT tires have better thread protection even when worn out. I have no issues wearing my TV tires down and still having them loaded to the Max. And in 40 years I can count only one TV tire flat. While I had at least one ST tire failures every long trip south. I carries aluminium sheeting and pop rivetter for repaires to the wheel wells. Never needed it with LT tires.
I worked in heavy equipment maintenance most of my life and always use the opportunity to improve failing OEM equipment. Most are designed for profit and competion dictate the quality. Never used warranty service because its the same old inadequate equipment supplied.

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drfife

Member
All I know is what I've experienced.I had 8 (eight) ST tires failures on my previous travel trailer over a period of 6 years.

The first 3 were North American made Goodyear Marathon 15" load range D tires. After conversations with a Goodyear exec, they sent 4 new Goodyear Marathon load range D tires, also made in North America.

I was not overloaded. I weighed the rig multiple times and have RVSEF documentation to prove individual wheel weights.I checked the tire pressure before every tow.I never towed in excess of 65 mph.

Less than 2 years later, 2 of the replacement Marathon ST's D's had failed.i replaced those with Carslile ST load range E. Over the next 2 years, 3 of those failed.

When those failed I replaced them one at a time with Maxxis ST E's. Never had a Maxxis fail.

I'm disgusted the tire manufacturers blame this on the consumer. I did everything according to the book and still had problems. Maybe it's because I live in Texas and the pavement is hot (almost all failures occurred on hot days). Maybe it's because I tow 10K miles per year.

When I ordered my current 5th wheel I specified 17.5" commercial Michelin LT tires. I'm confident I won't have the same problems with these LT tires.

Off my soapbox......
 

Gary521

Well-known member
Tireman9, I understand what you are saying about us all jumping to conclusions related to ST tires and made in China. So what is so wrong with using LT tires on trailers? I look at a lot of trailer forums too and have not, to my limited memory, heard any negative issues about LT tire use.
 

mattpopp

Trouble Maker
My Cooper 17.5's are made in China yet I have 100% confidence in them being that they are rated for drive axles as well. Along with a 4805lb rating at 75 mph.


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whp4262

Well-known member
Actually airplanes use Nitrogen in there tires because of the instant extreme temperature changes when landing. Having oxygen in the tires when they heat up so quickly could prove to be lethal.

It's recommend that every type of accumulator be charged with Nitrogen. Pretty much every shock or strut on the road or air is charged with nitrogen.

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Tires don't get hot enough during landing to cause a problem it's braking that causes the most heat and that's why turn around times are based on brake energy not tire temperature. If the tire reaches critical temperature it will melt the thermal plugs deflating the tire. The following paragraphs are copied from the Aviation Airframe Handbook.

(
The inner wheel half of a wheel used on a high performanceaircraft is likely to have one or more thermal plugs.​
[Figure 13-61]​
During heavy braking, temperatures canbecome so great that tire temperature and pressure rise to alevel resulting in explosion of the wheel and tire assembly.The thermal plug core is filled with a low melting pointalloy. Before tire and wheel temperatures reach the point ofexplosion, the core melts and deflates the tire. The tire mustbe removed from service, and the wheel must be inspected in
accordance with the wheel manufacturer’s instructions before
return to service if a thermal plug melts. Adjacent wheelassemblies should also be inspected for signs of damage. Aheat shield is commonly installed under the inserts designedto engage the brake rotor to assist in protecting the wheel and​
tire assembly from overheating.)

(
For the initial inflation of an aircraft tire and wheel assembly,the tire must be placed in a tire inflation safety cage andtreated as though it may explode due to wheel or tire failure.The inflation hose should be attached to the tire valve stem,and inflation pressure should be regulated from a safedistance away. A minimum of 30 feet is recommended. Airor nitrogen should be introduced gradually as specified.Dry nitrogen keeps the introduction of water into the tireto a minimum, which helps prevent corrosion. Observethe tire seating progress on the wheel rim while it inflates.Depressurize the tire before approaching it to investigate​
any observed issue.)
[Figure 13-154]
 

Grey Ghost

Well-known member
:confused: Anyone had any experience with Michelin LTX M/S2 tires on their units? Talked to a dealer and this is what they recommend, said the Michelin Ribs were better but for $86.00 more per tire might be an over kill. Just wondering? Thanks
 
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