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Why do tires fail? Our tire expert explains

The vast majority of 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 travel trailer and fifth wheel owners fail to realize that they will never “feel” the results of a tire losing air until it is too late. They are surprised when the sidewall lets go. The rapid air loss “bang,” even when the tire only has 5 to 20 psi in it, is a big surprise, IF they even hear it.

If you find any cords that look like this,

that is the evidence of a “run low flex” failure. Even if you don’t remember or don’t think you ran while the tire was low on air, this is the “smoking gun.”

A TPMS can provide a warning of air loss

A TPMS can provide a warning of air loss, so it is good insurance and can easily pay for itself. TPMS is not intended or designed to warn of a long-term structural failure. There is no consumer-level technology that can provide a warning to a driver on an impending belt separation

The long-term degradation of the rubber at the edges of the belts 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 for each increase of 18 F (4 times with a 36 F temperature increase). Running a margin of at least 10% above the minimum needed to support the load capacity specified in the Load & Inflation tables is a good first step. Running at speeds above 65 on travel trailers or fifth wheels, or above 75 on Class C  or A, will also generate excess heat. That is higher than the stated max speed found in the data books of the major tire companies.

Belt detachments

Here is an example of a tire with “belt detachments” as sometimes found on travel trailers.

 

Realizing that over half of the RVs on the road have one or more tire or axle in overload is one main contributor to their 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 those that want to blame the country of origin make just as much sense.

I have a few posts on my blog www.RVTireSafety.net on how you can get a tire engineer-level inspection by doing a free spin rotation as seen here.

Tire “wobble” needs to be inspected by dealer ASAP

If you see this kind of “wobble,” the tire is probably in the process of failing. It should be inspected by a dealer as soon as possible and probably replaced.

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 by the 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?

The term “blowout” is just a catch-all term to describe a failure where the person has no formal training in failed tire inspection or analysis.

Roger Marble

Check out my Blog www.RVTireSafety.Net

Have a tire question? Ask Roger on his RV Tires Forum here. It’s hosted by RVtravel.com and moderated by Roger. He’ll be happy to help you.

Read more from Roger Marble on RVtravel.com.

 ##RVT1101

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Gary Bate
1 month ago

So the key to tire maintenance is keep them in new condition. I’ve found that black hi gloss spray paint works great ! Those suckers always look new, I keep a couple of spray cans with me for on the road touch ups.

Roger Marble
1 month ago
Reply to  Gary Bate

I trust your post was tongue-in-cheek. External “look” is almost never a reliable way to judge the condition and integrity of the structure of your tires.

captain gort
1 month ago

I recently installed a set of Goodyear Endurance tires on our 2018-built TT. OEM tires looked fine, but I was worried about age. I also moved up to the largest size that would fit on the wheel to add a bit more capacity margin (although I still limit my load to the TT’s posted maximum). I’ve read the “China Bomb” stories. I’m sure some are true, but its also true of some USA-made tires. And I’d bet some “China-made” tires are actually really good. I suspect reliability mostly depends on load, age, weathering, inflation, and driving habits.

Kenny
1 month ago

The only time my TPMS ever helped me was when the tires blew. No warning. No help.

Roger Marble
1 month ago
Reply to  Kenny

TPMS will only warn when tire loses air or sometimes if the wheel/huub/brakes get hot enough to exceed the High Temp setting. Belt separations will almost never generate a TPMS warning. That is why I strongly recommend an annual “Free Spin Inspection” as I outlined in this post on my RV Tire Safety blog.

tom
1 month ago

Sorry that we missed you at Perry. Maybe we will have better luck in Tucson.

Roger Marble
1 month ago
Reply to  tom

I am scheduled to be at Gillette. Not sure about TUCSON yet.

Seann Fox
1 month ago

I would never buy the cheapest tires I can find. I always go with quality name brands and then look for a deal on those HOWEVER before I let them install the tires I always check the manufacturing date stamped on the sidewalls. Some places will have “a good price” on expired tires. Needless to say I won’t allow them to put those on my rig.

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