Another tire debate

[cwf]

Originally Posted by Tireman9

And the "presenter" had a Bachelor of Science degree from what school? and had worked as a Tire Engineer with product responsibility for what tire company?

I would challenge the "presenter" to provide any scientific date that supports his recommendation to "underinflate" a tire.

I do have a BSME from Ohio Northern Univ. I do hold two US Patents for tire designs. I do have 40 years experience with tire design responsibility. I have been personally responsible for conducting well over 10,000 tire autopsies to learn the "cause" for the failure.
While he said some correct things he clearly has had no formal training in tire design and I would doubt he has ever performed a failed tire autopsy.
I have given training class to US DOT engineers on failed tire inspection and analysis.

I wonder if the "presenter" can explain this failure.

SO here we have a "new" tire i.e. zero miles, mounted as a spare. Clearly it has failed. How does the idea of parking for long time causing failure work? Capri, you are not allowed to answer.

I think the presenter should have informed the people "Hi, I'm not a real tire engineer, but I play one at Camping World"

Meeces? That's plural fer mice...

Seriously, looks like it was over inflated? Or way something thrown from TV? Or failed when put on ground as spare?????

Obviously I don't know....

[PharmGeek]

I work in medicine. In order for me to effectively explain or debate a "controversial" concept with either lay people or with fellow professionals....it is of great help to cite the actual peer reviewed research on the subject.

Without that step, largely it is people making arguments from authority. Nothing wrong necessarily with having authority on a subject...but it seems to me that much of these debates NEVER cite meaningful research for onlookers to review.

Usually it helps if there is a "scientific consensus" that is based on the more inclusive "meta" analysis of the wealth of data on a given topic....but it often seems that there is very little or no useful specific research about say trailer tires, or hitches, etc....just personal expertise and aggregations of personal experience.

Or so it seems to me.

For the record, I do appreciate reading all points of view on the subject (and others), their personal experience, and knowing their credentials also does add weight.

I guess what I am saying is...if there are peer reviewed controlled trials on this subject, will the experts share them? Thanks.

[gmw photos]

Let's see.... a seminar presenter at CW. I just looked on their website, and they sell.... GYM ST tires. I bet they had them for sale in the store too.

Coincidence, that he recommended them ? Hmmmmm, let me ponder that a while....

[Tireman9]

PharmGeek
Peer review does exist in tire failure analysis. There is a published book with pictures of various tire conditions. Tire Maintenance Council Radial Tire Condition Analysis Guide. The conditions, their probable cause and corrective action, if any, has been reviewed by Engineers (note capitol E as indicating having at least a BS degree not engineers as too many technicians call themselves. This might be like a "medical tech" calling themselves a Doctor)
An older version (1994)of this document can be found HERE. Readers should be aware that this is primarily heavy truck with a strong focus on older design tires, so has been superseded by the new "Radial Tire" version.

These Tire Engineers have been selected by the various tire companies such as Michelin, Bridgestone, Goodyear and others to reach consensus for each condition.
I personally have taken the photographs and provided input for a number of conditions as published in the current manual. The book is copyrighted so I cannot provide copies from the manual.
I do write a blog RVTireSafety.com and have given a number of examples of various conditions using other photographs similar to those published in the TMC book.
I am "published" having an article in "Tire Technology International", an industry technical journal.

Despite all of the above, I do note that many do not want to be presented with data and facts that do not match their per-concieved ideas.

Saying we need to consider all points of view is really no more correct than suggesting we need to give equal credence to a Amazon witch doctor as we do to the head of Cardiology at a large hospital. While those holding various ideas and concepts have that right, not all ideas or concepts deserve equal attention nor should they be given equal credence.

Roger

[GCinSC2]

Tireman9,

No clue what did it in. But that can I call it a radial cut in the sidewall is a puzzler along with the zero miles statement. I'll be watching and hoping to learn from your follow ups.

Thanks for offering your professional background and insight.

Stay tuned folks, same Bat time, same Bat channel.

[Tireman9]

Originally Posted by Jim J

Tireman, Glad you commented. What did the presenter say that you agree with? And a question for you: What is the tire construction difference between an ST tire and LT tire? Do you have a preference for use on Airstream Trailers?

Jim

I agree with "- Unload the trailer tires by taking weight out of trailer and/or jacking up trailer
- Driving at higher speeds tends to reduce tire wear and fuel mileage"

I do NOT agree that exceeding the max inflation on a tire is a good idea. I do feel inflating tires to the max is a good idea for tandem axle trailers as "Finite Eliment Analysis" indicates that setting trailer tires to their max will decrease (but not eliminate) the unique inter-ply shear forces seen with multi axle trailers.
I would doubt that the "presenter" even knows what Interply Shear is.
I have a POST specifically for trailer owners.

I cannot recommend a specific tire for all applications. I can only provide guidelines that if followed will reduce the likelihood of having a failure.
Many of these guidelines and suggestion have already been covered in my blog.

[jcanavera]

Originally Posted by Tireman9

I agree with "- Unload the trailer tires by taking weight out of trailer and/or jacking up trailer

Just curious for an Airstream. If you wanted to relieve weight by jacking it up where would you do it? We know we have the jack points that are labeled on the belly area just to the rear of the trailer. However in using this spot technically the wheels on the other side of the trailer are on the ground. Is there really anywhere that is safe to jack up, especially since you are doing both sides, that won't cause any structural issues? Then the next question, if there is are safe areas, how much do you jack up?

I've only taken a trailer off the ground once and that was an SOB that weighed about 2,000 lbs. I did it with 4 jack stands under the front and rear frame members that ran from side to side of the trailer. First I lowered the front of the trailer by the hitch jack. I put two jack stands at the rear frame and then cranked the trailer up. Once I got all four wheels off the ground I gave the jack a couple of additional turns to raise the front of the trailer slightly. I slipped in the jack stands on the front frame member and lowered the hitch jack taking all the weight off it. Pretty easy and this allowed me to remove all 4 wheels at once to allow me to get a new set of tires. This wouldn't be possible on an Airstream though.

Jack

[GCinSC2]

Originally Posted by Tireman9

I have a POST specifically for trailer owners.

Uh Fellow AS owners, take a minute to take a quick look at his link, then go get a cold one and start clicking and reading.

I've just hit the tips of these articles.

Tireman9, Thanks for the info, lots to learn.

Had to look up NOU, never knew about that one, been to Ravenna several times, horse show.

Gary

[GCinSC2]

Originally Posted by jcanavera

Just curious for an Airstream. If you wanted to relieve weight by jacking it up where would you do it? Jack

Jack,

Oh boy, I'm ready for the replies, but here is what I do.

I've had my 30' S/O up in the air more than I ever wanted for hydraulic brake work so I think I feel pretty comfortable with the jack.

I use the jack that comes with a pickup truck, but I use the 1 ton truck jack, not a 1 ton jack the jack for a 1 ton truck. It has a large base, screw drive not hydraulic so no jack stands. How much to raise it up, well the tires are still on the ground but the chassis has gone up enough to take a lot of the bulge out of the tires. I use some 4X4's as bases for the jack and they are placed between the wheels on that vertical section of frame plate between the axles.

As previously stated, our 1st outing I had to do the same thing due to finding tread bulges on 3 GYM's. Replaced 3 GYM's in camp Santee SC SP. The 4th was a Maxxis. I had a lot to learn., still trying to learn. That is why all of your inputs are of interest

I bet others will chime in, at this stage of the game I'm my own warranty center.

Gary

[switz]

I have used a 3 ton hydraulic jack that had built on stops like a typical jack stand. I put the lift head of the jack on the doubled frame member between the two axles. That is what I did to take two wheels at a time to Costco (putting the spare on just in case of a jack issue) to have the Michelin LTX (P) 235/75R15 XL tires mounted. The spare got a private trip.

If I acquired a second unit, that would seem to be a logical place on each side to lift some of the weight off the wheels while in storage.

Out of curiosity, if a person puts any vehicle up on blocks and removes the tires for some period of storage, should the tire air pressure be reduced to zero since there is no weight on the tire while stored? I have been told they should be stored in a dark cool space.

[Tireman9]

I do not own an Airstream. I have owned a "Mini-Wini", 26' race car hauler, slid-in truck camper, 20' towable (brand I don't recall) and currently own a Class-C by Coachmen.

I do not jack up my Coachmen over the winter but I do inflate the tires to 80 psi (the pressure on the tire sidewall). I do cover the tires with white covers over the winter and whenever I camp at a loaction for more than 1 day.
Jacking up the trailer and removing the tire is one of those things that in a perfect world would be easy to do but in reality it isn't.
I do understand the theoretical damage done from long term parking in one spot but again theory and reality clash. Lots of actions can theoretically cause microscopic problems but if you extend the life of a tire by 1 month if you were to jack it up every time you were planning to park for more than 3 months, would it be worth the effort? Probably not.

There are actions that are easy to do and relatively inexpensive that can provide real "bang for the buck". I have covered these in various posts on my blog but will touch the big ones here.

1. If you have a multi axle trailer your cold inflation should be the inflation on the tire.
2. Your actual static load should not exceed 85% of the max load on any individual tire.
3. You need to weigh and learn the actual load, when fully loaded and not simply take the total axle load and divide by the number of tires. You will NOT get the correct tire load by doing the simple division.
4. Get a TPMS so you will get a warning when (not if) you start to loose air due to puncture or leaking valve
5. Cover your tires with WHITE tire covers if they will be in the sun for better part of the day. A couple of hours in full sun does about same damage as a full day in the shade in Phoenix.
6. Replace the rubber parts of your bolt in tire valves whenever you buy a new tire.
7. Get and use a hand held gauge at least once a month, even if you have a TPMS. You will probably be adding 1 to 3 psi each month anyway to maintain the tire inflation.
8 NEVER drive on a tire that has lost 20% or more of its air. Structural damage will be done. Such damage is cumulative and this damage does not repair itself. (See post on Potato Salad)
9 Do not believe everything you read on the internet. Ask the poster for their actual training in failed tire analysis. Simply having owned tires from company XYZ does not make that person a knowledgeable source.
10 You might put on your To-Do list to read all the posts in my blog (including the ones where I later point out my errors), then you could subscribe so you get a notice when I do a new post. I do about 3 a month so you will net be overloaded.
11. Learn how to do a rotating tire inspection and do your tires at least once a year (see the video link in my Aug 3 2013 post) to see what a failed tire looks like before it comes apart.

12. In closing I suggest that if you do nothing else you read my post of July 22, 2012 which is an analysis of a "Blowout" on an Airstream. Some of you may recognize that this failure happened to a guy while on his long honeymoon. In this post you will learn the real reason the tire failed was due to loss of air and the driver having no warning (no TPMS) so he continued till he was flagged down.

[GCinSC2]

Tireman9,

Thanks for the information and I will be reading a bunch of the info on your link. I'd like to correct, I called it NOU, my error Ohio Northern University. Looks like its out in the cornfields of NW Ohio, hey thats the same idea as Jackson Center and not too far away.

Any chance you can enlighten us about the failure photo you posted?

Thanks,

Gary
A former Buckeye resident.

[Tireman9]

Originally Posted by GCinSC2

Tireman9,
Thanks for the information and I will be reading a bunch of the info on your link. I'd like to correct, I called it NOU, my error Ohio Northern University. Looks like its out in the cornfields of NW Ohio, hey thats the same idea as Jackson Center and not too far away.
Any chance you can enlighten us about the failure photo you posted?
Thanks,
Gary
A former Buckeye resident.

Ya ONU is out in the cornfields but is a top Engineering and Pharmacy Univ along with the College of Law.

RE Picture in post 159. I only saw the photo, not the tire, but have seen a number of similar failures, i.e. tires with 0 miles but "exploded" belt & tread.

In this case the failure was on the top side of the tire. That being in the sun the most. Heat is the #1 killer of tires and direct sunlight can heat a tire to 40 to 60 over ambient temperature. This heat degrades the internal rubber at two to four times the rate when just exposed to ambient temperature. Ultimately the internal forces can cause the rubber between the belts to start to fail at the molecular level. This can lead to cracking and tearing and with enough heat and time the belts come apart. If the tire is over-inflated the inflation force exceeds the ability of the belts to contain the forces.
This is an unusual condition but can happen with excessive inflation and heat.
I have seen similar where the person covered the tire with a tight black cover which makes things worse as it increases the heat and keeps the surrounding air from cooling the tire.

Hope this answers your question.

[GCinSC2]

Tireman9,

If one of your objectives is raising awareness and don't take your tires for granted, count me in.

Pure overheating blew up a tire that never ran, wow.

I spend a bit of time on I95 in SC and a LOT of containers come out of and back to Charleston. Incredible number of gators left all over the highway from the container chassis trailers I think.

I'm running a TPMS and these discussions catch my eye.

As an aside, I have a set of Michelin LTX M/S2 on my '05 Ram 2500 they have done very well and will be replaced with the same tire when its time.

As a transplanted Buckeye, Ohio sweet corn is one of our most missed standards for summer. Just can't get the same here in SC. Sorry native SC'er's, ain't so. And what about Chardon and Geauga County spring time maple syrup oh boy.

Got more reading to do.

[switz]

I had the spare 13" ST tire on my motorcycle trailer parked outside in the Phoenix area year round. One morning I went out and the tread was completely lifted from the tire. I picked up loose junks of tread. The tire had never been on the ground and was stored with close to sidewall pressure.

I put white covers on the new tires. Two years later, the side walls are checking with perhaps 2,500 miles on them. I replaced the three ST tires yesterday with Michelin 13" "P" rated tires with a little less capacity. Derating the 1,047 pound sidewall load to 942 pounds each tire, that adds up to 1884 pounds and the maximum possible total load with my GoldWing is 1,150 pounds, so there is plenty of reserve capacity.

YMMV

[CapriRacer]

The tire that Tireman9 had a photo of: Zero miles and obviously failed.

I have seen several examples of this type of failure, normally a very old tire or one that has a damaged belt.

What is going on is that the belts restrict the tire's growth and as the rubber matrix deteriorates over time, its ability to withstand the stress gets to a point where it no longer can. Usually the belt as a layer pulls itself out of the surrounding rubber and it remains intact, but detached.

A " new" tire with this condition leads me to believe there was a problem in the manufacture - and in particular, in the area of the belt. I could go into specifics, but that would serve no purpose. Those types of things are not apparent until they happen.

Please note, that I don't think that is the same - or even similar - to the issue of the belts coming off that are frequently reported. I think those are related to the design of the belt package - what material is used where and how much.

Why do I think they are different? In Tireman's example, the tread is NOT attached to the top belt, where the failure commonly being reported has the top belt coming loose from the bottom belt, but the tread is still firmly attached.

[Tireman9]

Not having the tire in our hands to look for all the small, but meaningful clues makes failed tire analysis a real challenge.

We can offer our opinions but these are not as high a probability of being correct as when we have the actual tire or at least numerous in focus, well lit close-up photographs.

The "exploded" belt package is very similar to tires I studied when doing a special project. We discovered that some relatively "young" less than 4 years old, can have this "failure" under the certain circumstances.