Why do tires fail?

Tireman9 · 07-31-2019, 02:46 PM

As an actual Tire Design and Quality Engineer, I know from my 40 years experience, including 20 with a primary focus on failed tire Forensic Inspection that tires fail from two basic causes.

Low air pressure
and/or
Long term degradation of the rubber usually from excess heat.

Low pressure (active leak from puncture or loose valve stem or valve core are the most common reasons) can lead to a Sidewall Flex failure or more commonly called a "Blowout". The sidewall cord can melt (polyester) or fatigue (steel). Many TT owners fail to realize that they will never "feel" the results of a tire losing air till it is too late and they are surprised when the sidewall lets go. The rapid air loss "bang" even when the tire only has about 10 to 20 psi in it, is a big surprise IF they even hear it. A TPMS can provide warning of air loss so is good insurance and a TPM system can easily pay for itself.

The long term degradation of the rubber at the edges of the belts in radial tires can lead to a belt and/or tread separation. Even if the tire keeps its air you can have this type of failure so a TPMS will not provide a warning. This degradation comes with age as the rubber is always losing flexibility. Just think of those rubber bands you found in the back of the desk drawer. Even in cool and dark they got brittle. HOWEVER, running at or near or above the load capacity of a tire will result in increased heat generation. Increased heat actually can accelerate the aging process with a doubling of the rate with each increase of 18F. Running a margin of at least 15% between tire capacity and measured load is a good first step. Running at higher speed will also generate excess heat. For ST type tires this means faster than 65 mph.

Realizing that over half of the RVs on the road have one or more tire in overload is one main contributor to the high tire failure rate. Simply thinking that a tire will fail because the tire plant building is painted blue rather than green is not logical, but many still have feelings along those lines when it comes to where a tire is made.

Buying the lowest cost "no-name" tires is, IMO a major contributor to poor results. If the main objective is the lowest cost tire why would anyone be surprised with short tire life.
Just paying more however is no guarantee of better quality. I believe the best tool available is comparing Warranty and service support.

Can you get a multi-year warranty on the tires? Is it possible to get Road Hazard coverage? Is there a nationwide network of dealers who stock the brand you are considering?

RipinSC · 07-31-2019, 03:04 PM

Great post.
Thanks

Woodworker · 07-31-2019, 04:23 PM

That is a great read thank you

**JFlightRisk** · 07-31-2019, 04:59 PM

Appreciate you expertise! Thanks for the explanation.

hboy · 07-31-2019, 06:17 PM

Good info. I love hearing from a pro! We all have our opinions, but sometimes it's not based on science or facts.

Question if you have time: I have a friend in the tire sales business who says, just replace your trailer tires after 4 years of service. Trailer tires often sit idle for long periods of time which create 'hard spots' on the tire causing failure. Is there any truth to that?

Thanks again.

**norty1** · 07-31-2019, 06:34 PM

Along with the excellent commentary, we notice what seems to reinforce the comments by seeing all the rv's with blown tires in the summer months over the winter months.

Our last trip was a 300 mile drive in 95+ temps. We saw many large and small rv's with tire problems.

RetiredOne · 07-31-2019, 06:45 PM

It seems the two biggest discussion items that get the most different opinions on the forum: tire pressures and batteries.

**JFlightRisk** · 07-31-2019, 07:31 PM

And oil.

jd99336 · 08-01-2019, 06:49 AM

My dad (who drive OTR truck for a couple of decades) taught me to be quick religious about my tire pressure. I check pressure at least every other day on the road (usually every day) but at least "thump" check them on the days I don't put the guage on them.

I know temperature and over-loading are high failure modes which leads me to a question for the OP. During one hot day in the middle of OK on our two month trip, the tires felt hotter than normal after a couple of hours at 65 mph. It made me think about buying one of those laser temperature "guns" to monitor the temps.

Do you have thoughts on this and what is a critical temperature for tires where a person should start being concerned. I realize the effect is cumulative degradation over time, but still....must be some reference points.

Woodworker · 08-01-2019, 07:01 AM

Quote:

Originally Posted by jd99336

My dad (who drive OTR truck for a couple of decades) taught me to be quick religious about my tire pressure. I check pressure at least every other day on the road (usually every day) but at least "thump" check them on the days I don't put the guage on them.

I know temperature and over-loading are high failure modes which leads me to a question for the OP. During one hot day in the middle of OK on our two month trip, the tires felt hotter than normal after a couple of hours at 65 mph. It made me think about buying one of those laser temperature "guns" to monitor the temps.

Do you have thoughts on this and what is a critical temperature for tires where a person should start being concerned. I realize the effect is cumulative degradation over time, but still....must be some reference points.

Even tho I have a TOMS system I bought one of those laser temp guns for piece of mind. I found the temp reading between that an the TPMS system was very close. I also like to check the temp of the hubs with it. The hand test is good and call me lazy but it's easier than bending over to put my hand on a hub.

**norty1** · 08-01-2019, 08:06 AM

First I had the laser temp gun, then the TSPS system of my choice. I still use both. The laser temp sensor is great for checking hubs, hot spots in the engine etc. Even a fan belt or pulley bearing will heat up before it fails.

Woodworker · 08-01-2019, 08:33 AM

Quote:

Originally Posted by norty1

First I had the laser temp gun, then the TSPS system of my choice. I still use both. The laser temp sensor is great for checking hubs, hot spots in the engine etc. Even a fan belt or pulley bearing will heat up before it fails.

They're also great for checkin the wife's temperature when you think you may have pushed her far during a trip. I just point it at her forehead and see what it reads LOL

**norty1** · 08-01-2019, 09:01 AM

Quote:

Originally Posted by Woodworker

They're also great for checkin the wife's temperature when you think you may have pushed her far during a trip. I just point it at her forehead and see what it reads LOL

There you go.

DrSmart · 08-01-2019, 09:10 AM

Tireman9

I had G614's on our last fiver. The new North Point has the Endurance. We attended a seminar recently that was hosted Jayco and they had a rep there from Tredit. They supply Jayco with the Endurance. He claimed that the E rated Endurance is new tire design and technology that provides the weight rating over 4000lbs and max speed over 80mph. He said the G614 was a very good tire but is based on old tire design and that the Endurance is a much better trailer tire than the G614. Still trying to get my head around an E rated being a better choice than the G. Do you have any knowledge on this comparison and tire engineering?

DonaandDon · 08-01-2019, 10:40 AM

Quote:

Originally Posted by Tireman9

As an actual Tire Design and Quality Engineer, I know from my 40 years experience, including 20 with a primary focus on failed tire Forensic Inspection that tires fail from two basic causes.

Low air pressure
and/or
Long term degradation of the rubber usually from excess heat.

Low pressure (active leak from puncture or loose valve stem or valve core are the most common reasons) can lead to a Sidewall Flex failure or more commonly called a "Blowout". The sidewall cord can melt (polyester) or fatigue (steel). Many TT owners fail to realize that they will never "feel" the results of a tire losing air till it is too late and they are surprised when the sidewall lets go. The rapid air loss "bang" even when the tire only has about 10 to 20 psi in it, is a big surprise IF they even hear it. A TPMS can provide warning of air loss so is good insurance and a TPM system can easily pay for itself.

The long term degradation of the rubber at the edges of the belts in radial tires can lead to a belt and/or tread separation. Even if the tire keeps its air you can have this type of failure so a TPMS will not provide a warning. This degradation comes with age as the rubber is always losing flexibility. Just think of those rubber bands you found in the back of the desk drawer. Even in cool and dark they got brittle. HOWEVER, running at or near or above the load capacity of a tire will result in increased heat generation. Increased heat actually can accelerate the aging process with a doubling of the rate with each increase of 18F. Running a margin of at least 15% between tire capacity and measured load is a good first step. Running at higher speed will also generate excess heat. For ST type tires this means faster than 65 mph.

Realizing that over half of the RVs on the road have one or more tire in overload is one main contributor to the high tire failure rate. Simply thinking that a tire will fail because the tire plant building is painted blue rather than green is not logical, but many still have feelings along those lines when it comes to where a tire is made.

Buying the lowest cost "no-name" tires is, IMO a major contributor to poor results. If the main objective is the lowest cost tire why would anyone be surprised with short tire life.
Just paying more however is no guarantee of better quality. I believe the best tool available is comparing Warranty and service support.

Can you get a multi-year warranty on the tires? Is it possible to get Road Hazard coverage? Is there a nationwide network of dealers who stock the brand you are considering?

Great post. Can you lay credence to tire failure and tire balance?

Tunce the traveler · 08-01-2019, 10:41 AM

Quote:

Originally Posted by Woodworker

They're also great for checkin the wife's temperature when you think you may have pushed her far during a trip. I just point it at her forehead and see what it reads LOL

It’s not her forehead but is the reading accurate enough?

Woodworker · 08-01-2019, 10:55 AM

Quote:

Originally Posted by Tunce the traveler

It’s not her forehead but is the reading accurate enough?

LOL, close enough

North of 49° · 08-01-2019, 10:57 AM

Quote:

Originally Posted by Tunce the traveler

It’s not her forehead but is the reading accurate enough?

Usually the volume of the exasperated sigh is a good indication....

Lee Moll · 08-07-2019, 02:01 PM

I have a Jayco 26bhs , 2015 - would like to replace all the tires - what do you guys recommend please

CamperStu · 08-07-2019, 03:35 PM

just attended my local RV dealer ( Sicards)who has bi monthly free seminars- they had a tire specialist from Goodyear who introduced their new "Endurance tire"
https://www.goodyearrvtires.com/tire-selector.aspx
and answered general questions around tire care.
who new that Ozone is a tire killer.???..i mentioned i place my trailer on jack stands and store my tires in my shed during the winter - i asked if this was a good practice - he indicated yes except that Ozone is bad for tires and normally people like me have an air compressor and this device generates a lot of Ozone so keep away from these types of devices.. better to just cover to protect from UV rays and leave on the trailer. somebody else asked during storage they drop the tire pressure in half -he strongly advised against this practice..
and finally somebody in the crowd indicated that in Ontario it is against the law to install any tire other than a ST rated trailer tire on an RV

Tires & Rims - Trailer Canada

who knew there was so much to learn about tires..OH and finally the Goodyear Endurance tire is a little more expensive but will last longer and less chance of blow outs..plus they have road hazard warranty/

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