RV Tire Safety – “China bomb” tires and McDonald’s fries? What?

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By Roger Marble

I continue to see people talking about “China bomb” tires. As an engineer, this makes me a bit sad that so many people appear to have such a poor understanding of the difference between “causation” and “correlation.”

It is true that a majority of the tires on RV trailers that fail were made in Asia, and for many folks that means “China.”

But I would ask: If 90+% of the tires applied to RV trailers were made in “China,” why are you apparently surprised to learn that 90+% of the tires that fail in RV trailer use were made in “China”?


In an effort to make the difference between “causation” and “correlation” a bit easier to understand I have sometimes offered the following example.

If you check with people in prison you will probably find that 90+% have eaten McDonald’s fries. Therefore, it could be concluded that eating those fries can be considered something like a “gateway drug” to breaking the law and ending up in prison. I think we can see that that conclusion is not sound or reasonable, but clearly the numbers are similar to what we see in the RV community.

Yes, tires on RV trailers have a shorter life than in other applications, but the major reasons for the higher rate is clearly a combination of factors. Those factors include the documented very high percentage of RV trailers with tires in overload/under-inflation condition, as well as the clearly identified impact on belt separations due to Interply Shear due to the suspension design of multi-axle RV trailers.

 

Read more from Roger Marble on his blog at RVtiresafety.net.

 

 


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Roger MarbleMarmotLee EnsmingerKevin LovingDry Creek Recent comment authors

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Thomas Starling
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Using compressed nitrogen instead of compressed air, available at a lot of larger tire dealers.
Nitrogen runs cooler, doesn’t increase pressure with heat near as much as AIR.
NASCAR and trucking industry has been using for years.

Roger Marble
Guest

Tire running heat is generated by the flexing of the rubber in a tire. The more flex the more heat. It could be argued that if the inflation pressure does not increase, as many proponents of using N2 claim then the tire will flex more which would actually result in the tire rubber running hotter.

Dry Creek
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Dry Creek

I have found the perfect balance. I like running an approximate 80/20 mix of Nitrogen/Oxygen. Sometimes I’ll let the O2 drift down to about 18% if I can find some quality Helium and Argon “spacer” gases. Every now and then some CO2 sneaks in, but I sternly warn it to stay out of my tires. Since it’s the heaviest component, I will roll my tires to where the valve stem is in the 6 o’clock position and “drain” the offending gas out…

Roger Marble
Guest

Wife & I got an absolutely GREAT laugh from your post. As a tire engineer, I can tell you that your plan is one of the best I have ever heard. Keep up the good work. Too bad more folks don’t “drain” the bad gas out of their tires.

Marmot
Guest
Marmot

AIR is already 70% nitrogen. Thinking that a 30% increase in nitrogen will make any difference whatsoever is delusional.

Thomas Becher
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Thomas Becher

Love your coulumn.Always interesting. That said, I blew 3 tires on interstate 10 in Texas on a 94 degree day. Brand new BLACK TOP ,80#’s in tires 4 years old Uniroyal made in the USA. Goes to show not everything made in the US is that good or made in China is that bad. I think the road was too hot?

Roger Marble
Guest

Tom the hottest locating in a tire is at the belt edges, not the tread surface. This is even true at 200 mph at Indy. I didn’t know that Uniroyal made ST type tires or were they truck tires?

Lee Ensminger
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Lee Ensminger

I’d also be curious to know how FAST you were driving, Thomas. Could you share that as well?

Kevin Loving
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Kevin Loving

Are you saying ALL tires are equal? Are you suggesting that there are not CHEEP TIRES that is used by the industry to save a buck?

Roger Marble
Guest

Not at all. I am saying that there are a very small number of folks that have the knowledge and experience to properly diagnose tire failure and determine the “Root Cause” (i.e. do a proper autopsy). Simply claiming that a tire failed because it was made in a certain country is as scientific as claiming a tire failed because the plant building was painted blue. Take a look at the picture in this blog post http://www.rvtiresafety.net/2012/07/run-low-flex-failure-real-life.html
and without reading my analysis tell me why it failed.

Kevin Loving
Guest
Kevin Loving

I realize that quality is made in China. It depends on the specifications the item is made to. My complaint is that many manufacturers install tires that are not designed to carry the loads required by the RV they are putting them on. This decision to save money could literally be a LIFE AND DEATH decision! One of the reasons I bought a Outdoor RV is because of the tires that came on it.
I am not a “expert”, I HAVE to depend on people who are supposed to know what they are talking about.

John R McConnell
Guest
John R McConnell

Roger what you say is true. Many tire failures are due to under inflation, overload or even tires that are too old. I have had issues with the China tires and I always check inflation each time I start a trip. I also use a temp gun to check temps of tires and wheel bearings. I had just bought a new toy hauler and we took a trip to Calif from Ala. We made it to Texas and had a blowout. I know the inflation was correct and the tires were less than two years old (date of manuf on… Read more »

Dry Creek
Guest
Dry Creek

And the Goodyear Marathon ST rated tires were never thought of as being failure prone?

I know the inflation pressure of the tires on my RV are correct each day before I start driving. And, I know they are correct as I drive because I have a TPMS. You can’t assume that the anecdotal tire failure you cite wasn’t due to a slow leak that you weren’t aware of.

Jeff
Guest
Jeff

ROGER: You forgot to mention that everyone in Prison is INNOCENT Too! LMAO!

Patrick Granahan
Guest
Patrick Granahan

Enjoyed your most informative report….now I am considering giving up eating
McDonald’s French fries.