My biggest fear. . . .

[slowmover]

So fAr as I can tell from reading around in the past few years there are no guarantees that a TPMS will catch a blowout before it happens. But it is pretty good about leaks, fairly fast and slow. The aftermarket ones have their problems, so read for details to which to attend before buying

[Skater]

Originally Posted by slowmover

So fAr as I can tell from reading around in the past few years there are no guarantees that a TPMS will catch a blowout before it happens.

Of course, nothing is guaranteed, and who knows how fast the tire heats up before it explodes - if it's really fast, you might get the warning too late to help anyway.

Theoretically, if I could set one to alert at, say, 140 degrees, and I know that 120 is the normal max, that would probably be good enough, assuming that the heat buildup happens before it explodes and not after. Or, an increase in pressure (as a result of the heat, above a normal warm-up period) should indicate a problem, too.

The aftermarket ones have their problems, so read for details to which to attend before buying

Yeah, this is one of the reasons I haven't yet purchased one - mixed reviews for some models. When we got the set of tires that exploded, I had them put on metal valve stems in case I did find a TPMS that I wanted, but I've been hesitating since.

Given that we're looking at probably several hundred dollars in repairs, plus the expensive service call to an Ohio rest area, a TPMS that would have warned us with enough time to pull off could easily save its cost.

[Wayne&Sam]

I have the Dill TPMS. They are not valve cap senders, they install inside the tire like OEM units and have a metal stem. The receiver gives pressure and temperature alarms and you can set the alarm point.

Fortunately I haven't had to put it to a real test, but it certainly gives me peace of mind.

[Tireman9]

OK looks like we need a better understanding of tire failure.

The term "blowout" is used by laymen to describe what is really a Run Low Flex Failure. The sequence is...
1. The tire starts to loose air (puncture, cut leaking valve etc)
2. The driver continues at highway speed not knowing the tire was leaking.
3. The tire leaks down to below 50% and continues to leak
4. The excess sidewall flexing creates enough heat to actually melt the body cord (ie greater than 400F)
5 Polyester & Nylon body cord loose their strength as the material approaches melting point
6. The sidewall fails when there is no body cord in the sidewall since it has melted and flexed tot he point that there is not enough strength to retain the inflation.
Here is the physical evidence of melted body cord from a "Blowout"


The cord melts and gets hard just as the end of Nylon or Polyester rope does when you melt the cut end with a match.

The issue how the body gets so hot. It can't if it is inflated properly but once the air leaks out it can only take minutes of flex at highway speed to generate sufficient heat.

Yes TPM can give high temp warning but if that is what you are waiting ofr it is probabaly too late to avoid tire failure and RV damage.

[dkottum]

It is the damage that frequently occurs even when TPMS are installed that has led me to stop using them when the TPMS batteries expired (new senders at $50 each times four). I think they are a clunky makeshift solution that needs development, not worth the money. That's not a recommendation, just what we do and why.

Instead we spent the money towards 16" Michelin LTX tires to replace original GYM's. Much, much better reliability record. I have not seen a "blowout" reported on these.

[Skater]

Originally Posted by dkottum

It is the damage that frequently occurs even when TPMS are installed that has led me to stop using them when the TPMS batteries expired (new senders at $50 each times four). I think they are a clunky makeshift solution that needs development, not worth the money. That's not a recommendation, just what we do and why.

Thanks. That's what I was wondering - if there was someone here that had an active TPMS and still had problems, and what the result of it was.

Of course, it's possible the system you had didn't work well and another one would work better. Unfortunately, most of the reviews online are written by people who got it and haven't actually USED it (i.e., had a failure/leak/etc.), so you get "the display is awesome and I'm so much safer!!!", when in reality they don't know how it'll do when they actually have a problem. It reminds me of this.

Tireman, thanks for the explanation. My only concern with the sequence of events you described, in my case, is that I had two tires fail on opposite sides of the trailer, and they were the rear tires, and I have metal valve stems. So I can't figure out how the two tires would have developed the original leak in that sequence of events - it seems extremely unlikely to have hit something that would cause them to lose air, but not the front tires; the valve stems were fine and in fact were reused on the new tires; etc. When the shop unmounted the old front tires, they both looked fine inside and out, and were still holding 60 PSI, so we replaced our dry-rotted spare with one of those.

If I followed your description, though, theoretically a low tire pressure warning would have alerted us to a problem before the blowout.

For what it's worth, I saw at least two SOB campers, and two or three cars with shredded tires on our way back home Sunday. Hot day, in the high 80s. Apparently, it's that time of year!

(Sorry to the OP for derailing the thread. It was a rough day for us, and I really just wanted to convey that the blowout - sorry, Tireman - is the part that can damage the trailer, not just running on a flat tire.)

[Tireman9]

Originally Posted by dkottum

It is the damage that frequently occurs even when TPMS are installed that has led me to stop using them when the TPMS batteries expired (new senders at $50 each times four). I think they are a clunky makeshift solution that needs development, not worth the money. That's not a recommendation, just what we do and why.

Instead we spent the money towards 16" Michelin LTX tires to replace original GYM's. Much, much better reliability record. I have not seen a "blowout" reported on these.

TPMS will not actively prevent a tire failure any more than an oil pressure gauge will prevent a damaged engine. Their intent is to monitor pressure and warn the driver when there is a loss. Some wait till you have lost a lot of pressure and others will warn if you loose as little as 3 psi.

You might consider a system that has user replaceable batteries. I did a post on my blog (check my bio for a lik) on "Best TPMS" with a list of features to consider when shopping.

[John&Vicki]

From my reading on this forum and experience with high performance cars a great way to have peace of mind is to upgrade to 16" wheels and Michelins. Excepting running over something in the road you will be almost blow-out proof.

I have 15" wheels with lousy ST Marathons that were new when I bought my trailer that are still on there because I can't stand to waste things. But I'm eagerly waiting for them to wear out so I replace them with the 16"/Michelin combination.

Cheers,
John

[Tireman9]

Originally Posted by Skater

Thanks. That's what I was wondering - if there was someone here that had an active TPMS and still had problems, and what the result of it was. By problem do you mean they still lost air or that the TPM didn't provide a warning? Two completely different situations.

Of course, it's possible the system you had didn't work well and another one would work better. I personally have been warned of a very slow leak on one tire by noting the difference between it and the other tires. -leak at tire/wheel interface due to wheel corrosion) I have read posts from a few who were warned and stopped before tire failure so it does work Unfortunately, most of the reviews online are written by people who got it and haven't actually USED it (i.e., had a failure/leak/etc.), so you get "the display is awesome and I'm so much safer!!!", when in reality they don't know how it'll do when they actually have a problem. It reminds me of this.

Tireman, thanks for the explanation. My only concern with the sequence of events you described, in my case, is that I had two tires fail on opposite sides of the trailer, and they were the rear tires, and I have metal valve stems. So I can't figure out how the two tires would have developed the original leak in that sequence of events - it seems extremely unlikely to have hit something that would cause them to lose air, but not the front tires; the valve stems were fine and in fact were reused on the new tires; etc. When the shop unmounted the old front tires, they both looked fine inside and out, and were still holding 60 PSI, so we replaced our dry-rotted spare with one of those.

Believe it or not but in the tire industry we know that rear tires have slightly higher probability of puncture. This is due to the front tire running over the nail for example and after kicking up the nail it then can more easily puncture the tire behind it. Remember we are playing the odds here. Here is an example.

How can a piece of wood puncture a steel belted radial? Clearly it could not have been laying flat on the ground so the front tire must have kicked it up and it just happened to be at the right angle to puncture the rear tire. Without a detailed examination of your failed tires it is impossible to offer more than suggestions on what has been observed in other tires.

If I followed your description, though, theoretically a low tire pressure warning would have alerted us to a problem before the blowout. Yup

For what it's worth, I saw at least two SOB campers, and two or three cars with shredded tires on our way back home Sunday. Hot day, in the high 80s. Apparently, it's that time of year!

(Sorry to the OP for derailing the thread. It was a rough day for us, and I really just wanted to convey that the blowout - sorry, Tireman - is the part that can damage the trailer, not just running on a flat tire.)

Answers in RED

But running on a partially flat tire is what will most likely lead to a "Blowout". Fully inflated tires just don't fail in that manner and the evidence of the melted cord is the proof.

If you were not driving and let all the air out of the tire there would be no damage to the RV so you need more than a flat tire to give result of RV damage.

If your proper inflation is 65 cold and your running pressure is 70 and you were warned when the hot pressure dropped to 67 so you could stop before the tire was down to 50 there would be no "Blowout" as that isn't enough time to generate the heat necessary so no Blowout There are TPM systems that will warn of a "rapid" air loss of 3 psi or more from your HOT pressure in a couple of minutes

Cutting yourself with a knife can really hurt too, but if you don't have a knife its not likely that you will cut yourself.

Cause & effect and sequence of events are critical in analyzing an event and result or outcome.

The last 9 years of my career was basically "CSI -Akron". Its a thought process few do.

[sallye]

Can you replace 15" tires with 16" tires without changing the wheel? And is there always the space to do this? I would think that slightly larger tires would make the chances of blowout damage greater, since there is less space between them and the body. But then that much less space probably wouldn't make much difference.

Our tires are 2013, and we don't have that many miles on them yet (I am keeping track!). So it will be awhile before we change them out.

Interestingly, on page 8-7 the user's manual says "Most Airstream dealers cannot make adjustments to the tires. An Airstream, or tire dealer that handles that prticular brand, must do this." Really!

[John&Vicki]

Sallye...

You will need 16" wheels. The good news is that you only need two of them.

Cheers,
John

[jcanavera]

I think my biggest fear from a flat is the actual changing process. Years ago I saw a guy get hit and killed while changing a flat on his pop up while on the shoulder of I 44 about 28 miles southwest of St. Louis. His street side tire was flat, but due to the width of the shoulder and a drop off on the curb side of the shoulder he didn't have enough room to get the trailer and a person changing the tire out of harms way. I was traveling the opposite direction and saw his wife and kids standing in the grassy middle of the median to the rear of his trailer. He was down on his knees with the tire wrench, very close to passing traffic. I was thinking to myself that he picked a bad spot to pull over. As I passed by he passed by my view. Seconds later I heard a bang and looking in my drivers side mirror I saw the contents of his popup exploding into the air. I remember hearing the news report that someone drifted over into the shoulder area and hit him and the trailer. His wife and kids saw the whole thing happen. He was killed instantly.

I vowed that I would never get into that position and would pull my trailer on the rim if there wasn't an absolutely safe area to pull over. The guy's wife could have acted as a flagman but she had two small kids to control. At least she and the kids were in the center of the media and behind the trailer. They were not injured. This is also why I have road service on the trailer. Those guys in many cases will park their vehicles behind you with the nose of their vehicles sticking into the lanes. Much like the police do today when they pull over folks on the Interstates locally.

Jack

[sallye]

What a terrible story. . . . that poor family. And I'm sure it was horrible for you to see also.

We have a road side assistance plan also, and it's well worth waiting for!

[AWCHIEF]

The replacement batteries for my TST sensors are about $2X4 and takes only a couple of minutes to change. They are common batteries and are available almost anywhere batteries are sold. Makers estimate working life is about one year. Thankfully have not had to test the effectiveness of the system in an actual emergency situation.


Jack, I have had two close friends killed on the side of the road while changing tires. One while changing his own car tire and another a State Trooper assisting a motorist. Needless and preventable tragedies both of them.

[Tireman9]

RE Changing tires on side of road and accidents

One thing I have never heard taught in any Driver Ed is to look where you want to go not at items of interest.
I know this is hard to do as a normal reaction is to look at the vehicle stopped at the side of the road.
You need to resist the tendency to look at the parked car as you will unconsiously drive toward it.

"Look where you WANT to go" NOT at some interesting or unusual on the side of the road

The above is why we are now instructed to move over to the left when we see an emergency vehicle stopped on the side of the road. Sadly too many stopped learning or improving their driving skills once they got their license.

Just doing more driving does not automatically make you a better driver. I saw this confirmed a number of times when teaching police how to do a better job of controlling their vehicles at speed. Many thought that because they spend hours behind the wheel that automatically made them better able to handle emergencies.

[jcanavera]

Tireman9
I took a motor cycle safety course and it was interesting that they pounded into our head to turn our heads and look into a turn. A lot of accidents occur with motorcyclists who try to turn, but are looking straight ahead. They end up not turning because of their head and eye positions. Your observation is well founded and in my practical experience your head position and eyes will control the direction that you are driving/riding in.

Jack

[GCinSC2]

Tireman,

I taught the Riding and Street Skills MSF class in the mid '90's. Getting riders to keep their heads up and turn your head for turns was a perpetual challenge. Then a light bulb goes off and all gets much better.

[Skater]

Originally Posted by jcanavera

I think my biggest fear from a flat is the actual changing process. Years ago I saw a guy get hit and killed while changing a flat on his pop up while on the shoulder of I 44 about 28 miles southwest of St. Louis. His street side tire was flat, but due to the width of the shoulder and a drop off on the curb side of the shoulder he didn't have enough room to get the trailer and a person changing the tire out of harms way. I was traveling the opposite direction and saw his wife and kids standing in the grassy middle of the median to the rear of his trailer. He was down on his knees with the tire wrench, very close to passing traffic. I was thinking to myself that he picked a bad spot to pull over. As I passed by he passed by my view. Seconds later I heard a bang and looking in my drivers side mirror I saw the contents of his popup exploding into the air. I remember hearing the news report that someone drifted over into the shoulder area and hit him and the trailer. His wife and kids saw the whole thing happen. He was killed instantly.

I vowed that I would never get into that position and would pull my trailer on the rim if there wasn't an absolutely safe area to pull over. The guy's wife could have acted as a flagman but she had two small kids to control. At least she and the kids were in the center of the media and behind the trailer. They were not injured. This is also why I have road service on the trailer. Those guys in many cases will park their vehicles behind you with the nose of their vehicles sticking into the lanes. Much like the police do today when they pull over folks on the Interstates locally.

Jack

That's horrible. Don't think this concern wasn't on my mind as we stopped twice to change tires. My concern is that the longer you're sitting alongside the interstate, the more likely you'll encounter that idiot that sees you and drives right into you, so my first thought is to get out of there as quickly as safely possible.

The street side tire went first on the PA Turnpike, and there was plenty of shoulder for me to pull off and work in, with good visibility from a distance, and be reasonably far from the traffic zipping by at 70+ mph (not that that's a guarantee, of course). The curbside issue was on the Ohio Turnpike, in an area where the shoulder was only a few feet wider than the camper and had a guide rail on the right edge. I was glad that it was the curbside tire.

I was in an accident 5 years ago with my B190 when a guy towing an enclosed car trailer had a flat tire on the trailer, pulled off, and didn't get entirely out of the lane. He was lucky - he was standing next to the trailer looking at the tire, but I hit the trailer square-on and pushed his rig forward instead of toward him.

There are so many reasons flat tires are bad.

My plan was to get 16" wheels and better tires when the previous set wore out. Our current wheels are mechanically fine, but ugly. We'll probably still do that in a year or two; we might as well get some use out of our new tires first.

Tireman, thanks for the explanations and updates.

[Tireman9]

Avoiding this situation is a BIG reason to get TPMS.

Assume your cold pressure is 65 so your hot pressure is maybe 72

With a good TPM that provides "rapid air loss" warning ie a warning when the pressure drops about 3 psi from the HOT pressure

So you are driving and the tire picks up a nail. Tires simply do not explode the instant they get a puncture so it takes a few minutes to loose air.

Your tire drops to 69 psi and you get a warning and your TPM displays the pressure. You and your co-driver scan the road ahead for a safe place to pull off while you watch the tire pressure.

A minute or so later the pressure has dropped to 65 but you have had a mile or more to find an exit or pull-out.
You may even have another couple of minutes and couple of miles to find a safe pull-off spot.

Now some TPM only warn when the tire has lost 15% from the cold set pressure. At this point you have probably lost 25% of your air and this has increased the flexing of the sidewall which increases heat and gets you closer to a sidewall flex failure or "Blowout" in laymens terms, so you really do not have more than a few seconds to find a place to pull off.

Your choice.

This "Rapid air loss" from the hot pressure is one of the items I cover in my blog post on "Best TPMS" of features to consider when selecting a TPMS.

You can read my Bio for info on my RV Tire blog.

[jump89]

I also have a 20' Flying Cloud. I've had one blowout with the GYM's. I don't wish to repeat it. Les Schwab saved the day however. Almost like a commercial. It's definitely a heavy 5,000 gvw single axle trailer.

So I'm looking to either go the 16" wheel and michelin route or try some Power King STR II replacements.

They're rated to 2830 lbs and Tire Rack says they're good to 75 mph.

Anyone have experience with them?

I've always had great experience with Michelins so I hesitate to consider anything else.

Thoughts?