= RV Tire Safety -BLOWOUT- A Real Life Experience

[Tireman9]

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 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 loosing 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. [moderator edit] A TPMS can provide warning of air loss so is good insurance and can easily pay for itself.

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 rubber is always loosing 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 each increase on 18F. Running a margin of at least 15% between capacity and measured load is a good first step. Running at higher speed will also generate excess heat.

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.

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 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?

[Tireman9]

I keep reading " I had a Blowout" when many times the failure is not a blowout simply due to high pressure. In fact I do not ever recall seeing any such failure properly identified on this or any other RV forum.

So I keep posting the same pictures of what a real Run Low Flex Failure or Run Low Flex Blowout looks like as seen below


RLOF is caused by driving on a tire that has lost significant air (more than 50%) for a number of miles.

[timetogo]

Really good info, should be a sticky.

[greystroke]

nice Tireman. Good Post.

What about speed? Speed generates more heat, right? I see some of these big rigs pass me like I am standing still. Most tables I look at list 75 as the max speed.

What happens to the tire for sustained speeds of 80-85??

[Funhaus]

Tireman I know what your saying about "blowout" but I think people generally refer to this as a blow out because it probably made a loud noise when it went, weather it was from high pressure or not, it's just a term that in your eyes is used incorrectly. Sort of like the person who comes home and finds stuff missing from their house and exclaims "I've been robbed," no you were a victim of theft or burglary, in most areas robbery is a face to face encounter which one or more people forcibly take property from its rightful owner.
A "blowout" can be a scary event, whether it happens from high pressure "blowing" out your tire or the tire just coming apart.
But thanks for the informative article, hopefully it will prevent people from having a "flat" tire.

[CampDaven]

This thread by Tireman9 says a lot, including failure via low pressure and the value of TPMS
Perhaps a cause of this event?
http://www.irv2.com/forums/f59/blowo...-a-309279.html

[GoneToTheDog]

Great information, Tireman! This should be mandatory in "RV 101" instructions, if there were such a thing.

Also...something I see many times with many RVs, and especially trailers...are scuffed sidewalls on tires. The driver cuts corners too closely/short at times, and 'curbs' the tire. Or, they drop off of the curb when turning/pulling out of a gas station, driveway, etc. Surely, that is very hard on the sidewall of the tire as well. I try to avoid doing that at all times.
I often see this same situation with the 'toad' vehicles behind motorhomes also. They just drag the toad right up over the curb, trying to make a sharp turn. Makes me cringe every time I see someone do that.

[Peter M]

Another scenario I have witnessed greater incident of blowout is the following .Super hot summer day the big rig has been on the HI way all day, the tires are very hot then a sudden cold rain downpour. The excess heat in the tire plus sudden cooling and contraction of tire lead to sidewall failure .

[Smitty77]

Tireman9 - Thanks for the post.

I refer many family members, and fellow RV'ers, to his site on RV tire safety... (Link in his signature thread.). I recommend this be a bookmark, as a valuable too in our RV'ing safety tool box...

I really appreciated Tireman9's help when I had two pothole damaged tire, he had me send him pictures, and helped me diagnose the tire condition. (Broken cord in one, and slipping cord in the other. And upon removal at TCI Tire Center, yep to both of his opinions.).

Best to Tireman9 - thanks again for sharing our knowledge with us...
Smitty

[CampDaven]

I think it should be a Stickie

[F76Marion]

Roger,

Good to see you here.

As soon as I saw the title, I was getting ready to post the link to your site just as I have lots of places since I heard you at Goshen.

I'm still going to keep posting that link everywhere there are tires.

Frank

[Betr2Trvl]

An acecdotal story to go along with the original post.

We were traveling southbound on I15 south of Salt Lake City in late July, my wife drivng our coach at our normal wide open interstate speed between 60-65mph. I think the speed limit was 75.

Lots of RVs, TTs, etc., but what had been noticeable to me was that it seemed a lot of big pick ups pulling TTs were flying past us, and keeping pace with autos that were 75mph+. At one point, I start smelling what seems to be burning rubber. I immediately look at my TST monitor to ensure that everything is fine with us, and at that point I hear a a"boom", not us, look up, and a big pick up with a TT that had just passed us blew a trailer tire. He couldn't have been 200 yards in front of us, still in the left lane when it blew. He got off the road just fine, and we did not hit any tire debris.

Given the apparent age and not well cared for look of the TT, it would not have been surprising that the tires were well past thier prime nor properly inflated, compounded by driving well over 75mph. Kind of a 3 for 3 on how to blow a tire........

I was going to post this story after it happened, but never got around to it, so this reminded me of that incident.

Be safe!

[Zigeuner]

So while on the subject of why tires fail, maybe someone can answer this, and if it needs to be it's own thread just say so. I had a short drive with fifth wheel camper below, topped off tires to 80#s before leaving. About 30 minutes into drive had a hard stop from about 40 mph to zero, don't think the tires locked up (no flat spots) but due to a dip in the road while braking the truck bucked pretty hard. Didn't think much of it then, and not sure if I should now. About thirty minutes later get to camp, back in with an easy left turn, didn't run over anything or turn sharp. Next afternoon the rear left trailer tire is absolutely flat. Changed tire, check for objects and find nothing other than a very small piece of wire about the thickness of a horse hair, and doubtful it was in deep enough to puncture the tire. Tire still holding air, no bubbles with soapy water. A week after I get home I notice the rear trailer tire on the other side is flat now...air it up and it is also holding now.

Coincidence? Bad luck? Can hard braking break the bead loose?

[Tireman9]

Originally Posted by greystroke

nice Tireman. Good Post.

What about speed? Speed generates more heat, right? I see some of these big rigs pass me like I am standing still. Most tables I look at list 75 as the max speed.

What happens to the tire for sustained speeds of 80-85??

More speed = more heat

More heat = shorter tire life.

FYI I drive 62 - 65 in my Class-C. Drove OHIO > Oregon > BC > MT > SD > OH in '15 using cruse at 62 - 63 so I don't buy the I can't drive slower than 75