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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
It is not a myth that over 50% of RVs have tires that are overloaded. It is not a myth that probably fewer than 15% monitor their tire inflation.
Why do so many feel having an engine temperature gauge or oil pressure gauge is important to monitor their engine even though they almost never run it any faster than 80% of redline. BUT almost all trailers operate some portion of the time at 95 to 120% of the tire redline but can't be bothered to monitor their tire temperature or pressure.
If almost 100% of ST tires applied to RVs are made in China why are so many surprised to learn that a lot of Chinese made tires fail.
I do not believe that all tires made in China are bad even though I have seen some tires that were made in China with possible design or manufacturing weakness.
I also do not believe that eating McDonald's fries makes someone a criminal even though a vast majority of criminals have eaten McDonald's fries.
Association does not prove causation.
I fault our education system for not doing a better job of teaching logic and science so people understand there is a great difference between having facts and data to prove A caused B and simply observing that since C happened with D that does not prove C was caused by D.
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Tireman9
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05/14/13 07:58am |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
A fundamental problem of the NHTSA complaint file is that very few individuals seem able to provide the most basic facts about their tires.
Lets set aside the question of expecting the average consumer to correctly identify the real reason for the tire to fail. On my blog, I have documented with pictures, too many cases of improper diagnosis to have any confidence that that part of a complaint is accurate.
How is NHTSA supposed to classify a tire size given as "235-15" ?
Why do people report tires being made by "Cooper Tire Co" when Cooper hasn't made that size or line for 20 years?
NHTSA needs accurate DOT serial number so they can trace the tire in question but again providing the full DOT serial as molded into the sidewall of the tire is many times just beyond the capabilities of most individuals.
The willingness of the RV buyer to tolerate 12 month warranty on their unit is the main reason the RV companies don't do anything to improve the quality of their product. Look at Detroit warranties in 1970. They were for the most part 12 months which is what the RV buyer tolerates 40 years later.
When was the last time anyone was able to get the RV repaired 3 or 5 years after sale? Why are you demanding this of only one component, your tires?
Why aren't you demanding the RV manufacturer stand behind the components they selected to assemble and sell?
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Tireman9
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05/12/13 11:31am |
Tech Issues
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RE: Tire question
GVWR 5500 and dual axles. It seems it does exceed whats rated.
Your info is a little confusing.
You say you have a tandem axle trailer with a GVWR of 5500# but you have weighed the trailer and exceed that rating.
What is your actual load on each tire?
You also say you have P215/75R15 on the trailer now.
You did not say if you had Standard Load i.e. 35psi inflation or "Extra Load" 41 psi rating. What inflation do you run in these tires?
You are asking if it is OK to go down in size to ST205/75D15 LR-C.
Fasteagle pointed out the de-rating issue when you run Passenger tires on a trailer application. There is additional load reduction for "P" type tires in that the "normal load" (that means the load you regularly run at) for passenger type tire application should "not be greater than 94% of the load capacity of the tires" according to US Tire & Rim Association.
Your GoodyearGoodyear passenger tire option is rated at 1742# before we do the 1.1 de-rating and apply the 94%. This means the maximum "Normal" load should never exceed 1488# per tire.
Important information you have not provided but is needed by those trying to provide accurate answer to your questions.
1. What type & size and Load Range tire is shown on your TT certification placard?
2. What is the actual load on each individual tire when the TT is fully loaded? NOTE this is not the figure you get from a single scale reading divided by 4 as less than 1% of RVs have perfect 50/50 side to side as well as 50/50 axle to axle loading.
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Tireman9
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03/22/13 11:26am |
Travel Trailers
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RE: blow-out damage to trailer
I'd like to have some temperature sensors for the tires. I would think they would be better than pressure sensors.
Dusty
Since it is the air that carries the load and decreases deflection with an increase in pressure
AND since it is bending due to deflection that generates heat
AND since the hottest part of the tire is internal to the structure either at the belt edge when properly inflated or in the body cord when the tire is under inflated
Measuring the temperature of the air inside the air chamber or even the temperature on the outside surface will give you a low reading.
Set your tires correctly using a calibrated digital gauge. Install a TPMS and note the pressure readings. You should never be below those readings.
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Tireman9
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03/03/13 12:59pm |
Tech Issues
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RE: blow-out damage to trailer
Maybe just add reinforcement to the sheet metal that you are already installing -- like some metal struts on the inside of the new wheel wells?
While there is nothing wrong with wanting to protect your RV from a tire explosion a little sheet metal isn't up to the job.
Take a look at http://youtu.be/_3_PMhBa_-c and know that the tubes used are at least 1/8" wall 2" dia or heavier. The truck tire may have more force than a 16" ST tire but you will also note that the tire isn't rotating.
Test drums in tire labs are completely enclosed with 3/16 steel grating similar to this or similar.
http://i45.tinypic.com/103iq6e.jpg height=320 width=240
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Tireman9
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03/02/13 07:44pm |
Tech Issues
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RE: blow-out damage to trailer
Just a silly question, does a TPMS really give you enough warning of a blow-out to get stopped before coach damage happens? Seems like a catastrophic failure would happen too fast. what is everyone's take on this
Most "Blowouts" are the result of running at highway speeds with the tire significantly under inflated. The time to fail the tire depends on load & inflation level but can happen in just a few minutes if the leak is fast to days if you only drive a few miles at a time such that the tire does not heat up much.
You might want to review the posts from July 22 on my blog. There are 7 other posts with that "label".
TPMS should warn you within a couple of minutes of loosing 10% of your setting (assuming you have set the TPMS correctly).
TPMS is not 100% but it is way better than just hoping you never get a puncture or have a valve leak.
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Tireman9
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03/02/13 07:25pm |
Tech Issues
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RE: Blowout
Is driving on one good tire on a duel set up OK in an emergency situation. Not something I figured you could do if needed. Not trying to hijack the thread but curious.
Simple answer is No.
I did a post on that specific topic "can-you-limp-home-on-failed-dual" on my blog June 27 2012 and I identify a speed that some might consider acceptable but I would not recommend it.
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Tireman9
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03/01/13 01:30pm |
Class A Motorhomes
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RE: Blowout
Had a blowout on rear duel 15 minutes into trip from Orlando back to NY. Used my new Rand McNally GPS to find an RV repair shop, I choose Crane RV Repair from the list, turns out to be a house in a residential district. I then remembered passing a Ford big truck dealer back off I4 so I statrted limping back to it. On my way back I spotted Orlando Freightliner in Apopka. Pulled in and sign said closed weekends but by the time I could figure my next move a gentleman came out to see what the problem was. Turns out they are open for service all weekend but don't do tires so he sent me 2 miles up the road to AOK tire mart. It was only 7AM so AOK wasn't open yet. The workers showed up about 7:45 and the boss man asked what he could do for me and I pointed to my tire. He said it would be no problem getting a tire on it for me. Before we start bashing a tire manufacturer let it be known I probably should have changed these long before this trip. I asked him to change all 4 235/80R22.5 rears as fronts were new. These guys started work early and had me back on road in less than an hour and a half. They were great, so if anyone has problems in Orlando area with tires don't be afraid to use these guys.
15 min sounds like the tire was flat when you started. It only takes a few minutes to fail a tire due to "Run Low Flex" which most call a Blowout. A TPMS will probably warn you of a loss of air and if you heed the warning and do not drive on a tire that has lost a significant amount of air you may be able to have the tire repaired and will almost certainly avoid the cost of damage to your RV.
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Tireman9
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03/01/13 01:24pm |
Class A Motorhomes
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RE: Tow Max STR ST 225 75R15 Tires
I note some posts with specific suggestions on inflation i.e. 60 or whatever. You all have a placard attached to left front side of your RV which indicates the minimum correct inflation. I believe that the placard inflation is the same inflation as seen on the tire sidewall.
There are sound engineering reasons to inflate trailer tires to the infl on the tire sidewall.
"Blowouts" Tires simply do not explode for no reason. Most tires fail due to either being run when underinflated and overloaded. If the underinflation is significant and the tire is leaking air iin all probability you will generate enough heat to melt the polyester body ply. At that point the hot rubber does not have enough strength and it ruptures rapidly and catastrophically. The physical evidence is hard ends to some of the polyester cord. Even a single cord melted is sufficient proof that the tire was being run while grossly underinflated.
Tireman
what temperature is normal operating temperature??? The Safe range of operating temperature??? And the temperature danger zone for the different types of tires, (important) including the ST and the LT tire if they are different…
with all the debate about tires and all the claims made about cause and effect of inflation and loading, I have never seen an adequate answer for tire temperatures even though the tire companies claim overheating from overloading or under inflation is the number one major cause of catastrophic tire failure…
At what temperature did the cords melt in the picture you provided???
Rubber looses much of its strength and starts to "de-vulcanize at a bit over 220F but this will vary depending on compound. Polyester looses half its strength in high 200's and melts at high 300's. The problem with trying to use these temperatures is that you have no way to measure these temperatures while running.
In racing, tire engineers use needle probes to get to the hot spots which are deep inside the structure where the heat is generated. Heat migrates out of the hot spots to the inner surface which transfers to the interior air then out through the cooler wheel. Heat also migrates out to the outside air but heat migration in rubber is slow so you can fail a tire in a couple of minutes or less but still have most of the tire at an acceptable temperature.
Rubber is a good insulator so unlike a metal hub you can have 100's of degrees difference between two spots on a tire and the failure is not based on the average temperature but on the highest spot. Also as the rubber gets hotter it flexes more which generates more heat so you can have a "runaway cascade" of heat generation and rubber strength loss.
If you have a TPMS that accurately measures the temperature of the air contained in the air chamber (screw on TPMS do not meet that requirement) then the normal would be about 70F above ambient for highway speed at normally loaded. I think you would find that most tires run at or below this level. If hotter then something is wrong (load, speed or inflation) and must be corrected. I have a post with details on my blog on June 16, 2011.
Infrared guns are OK for metal objects that generally are uniform in temperature but nowhere near focused enough for a meaningful tire temperatures if you are talking about dangerous high levels. Critical temperatures can exist in a tire while only an inch away the temperature could be 100F lower. I have a post on my blog just on that topic with examples from May 15, and May 19, 2012.
Sorry but I just cannot tell you that if you walk around your rig with your Harbor Freight IR gun and shoot each tire you will be OK as long as the temperature is below 164.5F. You and the gun just are not that consistent and the tire starts to cool down as soon as you start to slow down so even the rate at which you slow down and the time it takes to get out and get a measurement and even the distance from the one measurement spot on each tire will make a difference.
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Tireman9
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02/21/13 08:20am |
Travel Trailers
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RE: BFG Goodrich Commercial TA/AS LT 235/85 R16 Recall
UPDATE
Michelin denied my claim on my 0909 Commercial T/A Tire Failure. They determined the failed tire lost air and then failed. Good for them, within 3 hours of departing and having checked the tires that am, its not their fault the tire failed?
They recalled one of my NEWER BFGs earlier last year, and both my 0909 Tires failed within a month of each other.
They'll pay me $69 for the expense of shipping the totally failed tire to them for their examination.
So besides paying "prematurely" and inconveniently for two new tires to replace 0909 BFGs, I'm on the hook for paying for the damage to the RV.
Very dissapointing.
Did you get any sharp close up pictures of the failed BFG before you shipped it off to them?
Would need something at least as good as this. The worna Yellow and the holes in red are proof of run low
http://i45.tinypic.com/2z73mn6.jpg height=400 width=300
If polyester body this would be proof of run low
http://i53.tinypic.com/1rdw01.jpg height=400 width=300
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Tireman9
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02/19/13 03:55pm |
Fifth-Wheels
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RE: Tow Max STR ST 225 75R15 Tires
I note some posts with specific suggestions on inflation i.e. 60 or whatever. You all have a placard attached to left front side of your RV which indicates the minimum correct inflation. I believe that the placard inflation is the same inflation as seen on the tire sidewall.
There are sound engineering reasons to inflate trailer tires to the infl on the tire sidewall.
"Blowouts" Tires simply do not explode for no reason. Most tires fail due to either being run when underinflated and overloaded. If the underinflation is significant and the tire is leaking air iin all probability you will generate enough heat to melt the polyester body ply. At that point the hot rubber does not have enough strength and it ruptures rapidly and catastrophically. The physical evidence is hard ends to some of the polyester cord. Even a single cord melted is sufficient proof that the tire was being run while grossly underinflated.
http://i56.tinypic.com/2q8buoj.jpg
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Tireman9
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02/19/13 11:49am |
Travel Trailers
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RE: Tire Pressure Monitor - Worth it?
I've never had TPMS on my vehicles so I don't really know. However, anecdotally it appears that most trailer tire failures are catastrophic blowouts rather than from slow leaks which is what I thought TPMS would catch. Your question and a couple of the responses caused me to research TPMS online, where I found the following sentence: "The on-board computer alerts you with a warning signal that your tire pressure is too low or too high." Nowhere does the literature state that TPMS will measure higher temperatures, but I think what some are saying is that a higher pressure reading indicates a higher temperature, so if you get that warning you might be able to pull over before the tire blows.
So now my feeble mind is a bit more confused about TPMS. Regardless and since I don't have TPMS, I make sure my tires are properly aired each morning, and I use an inexpensive infrared temperature gun to check my wheel hubs and tires at each stop, testing not only for max temps but temperature differential between each wheel set. So far I've gotten remarkably consistent temperature readings so it appears the gun is fairly accurate. While I've decided not to add TPMS, you have to be the judge of whether it's worth it for you based on the above comments.
Most "catastrophic blowouts" are the result of slow leak which results in the body cord melting at the flex point in the sidewall.
http://i45.tinypic.com/2z73mn6.jpg
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Tireman9
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02/14/13 04:37pm |
Travel Trailers
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RE: Tire Pressure Monitor - Worth it?
We're going to be embarking on a 3 month trip to the heartland in May. I've been researching tire pressure monitors for the trailer. Some mount inside the rim and include the valve stem, others have a monitoring cap that fit on the existing stem.
Are these things worth the money? If they are, What type and brand are the best to buy.
Who sells an internal valve stem mount TPMS rated for 80 psi?
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Tireman9
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02/14/13 04:32pm |
Travel Trailers
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RE: Big Country Fith Wheel
Just an FYI
I just saw some pictures of some Tow-Max tires on a Heartland Big Country RV.
These were ST235/80R16 LR-E with a stated max Load of 3520#.
This is a special tire as the normal load rating for this size tire in the Tire & Rim Association standards book indicates this size is rated at 3420# @ 80 psi cold.
If you have 7000# axles and want to meet the information on your placard you may have to buy Towmax brand. This is strange as the other 9 sized match industry standards for load capacity according to the published http://www.towmaxtires.com/tires/Landing.aspx?application=towmax-product-line from Towmax.
You might check the details so you don't get a surprise down the road.
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Tireman9
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02/14/13 04:23pm |
Fifth-Wheels
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RE: ? G614 Tires
Then dont believe me but believe an American IR.
Mr Daws articles, take the 6th dot.
You don't have to read it all, but hover over it to the conclusions, top of page 5 is interesting, and the end conclusions.
Goal of all the calculations is to keep the deflection of the tire the same as when maximum load and reference-pressure on it.
Fact is that those lists are made by calculation, and they are different in America and Europe.
Fact also is that in basics American and European tires are not that different. So they should be calculated the same.
If you trust the load/capacity lists made "the american way" you could end up using to low pressures , though you think you are save.
And that is what I want to convince you of.
I wonder how many tires the poster or Mr Daws have designed and followed through the battery of tests run on OE tires and received approval for production. Mr Daws makes the statement "For vehicles being fitted with the Original Equipment (OE) tire, the recommended operating pressure is listed on the placard.
The normal methods employed for arriving at the correct inflation pressure are by interpolation in tables published by tire regulatory bodies, like the Tire & Rim Association (T&RA), or by computation using methods published by those same regulatory bodies."
I believe he is mixing two different concepts of how the recommended pressure is established. TRA, ETRTO & JATMA establish fitment standards and publish dimensional tolerances along with Load & Inflation information. Tires selected for OE vehicle application normally receive extensive evaluation to arrive at a recommended inflation from the vehicle manufacturer. I am not aware of any real vehicle manufacturer that goes through a development and approval process that simply selects an inflation from the tables. Nor am I aware of the vehicle manufacturer recommending an inflation based on the minimum inflation for the load specified in the tables, with one notable exception.
By "real" vehicle manufacturer I mean not a company that simply assembles a number of bits purchased from other manufacturers. Real manufacturers stand behind their entire vehicle and do not provide an owner with a long list of suppliers phone numbers when it comes to warranty claims.
Usually the placard inflation is higher than what would be dictated by the tables based on the normal load. This higher inflation is arrived at with numerous criteria being considered such as a balance of Ride, Handling, Fuel Economy, Noise and Traction etc.
The "recommended inflation pressure" listed on the placard is NOT set by the industry standards organizations nor the tire manufacturer and Mr Daws should know that.
Mr Daws is less than clear when he talks about the "Correct" inflation pressure. It is also important that the method for selecting the inflation pressure for improved durability for multi- axle trailers should not be the same as for motorized vehicles and this is confirmed through engineering Finite Element analysis. Again neither the poster nor Mr Daws seem to acknowledge these two types of vehicles have significantly different structural loading of their tires during normal operation. This different structural loading is why different methods of selecting a "recommended" inflation is called for when experienced tire engineers are involved with the decision.
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Tireman9
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01/21/13 02:20pm |
Fifth-Wheels
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RE: ? G614 Tires
we have used Goodyear G614's since early '06 .... we do tow a heavy 5er for thousands of miles each year and during that time we have had 3 tire failures which damaged our camper .... the reason we continue to use them is, that is the only tire I know of that if it fails within the first 4 years and Goodyear gets whatever is left of the tire back, they will pay for 100% of the damage and replace the tire .... if some company ever comes out with a tire that can't fail, I'll switch but until then we will pay more and use G614's
Jim
No such thing as a fail proof tire. As long as owners insist on overloading and/or under-inflating their tires they should expect to get tire failures.
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Tireman9
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01/21/13 08:24am |
Fifth-Wheels
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RE: Discussion on new tires and question about speed.
Interesting discussion. I guess. But maybe we might want to step back a bit.
Given the proven lack of knowledge of RV owners to properly identify the tires they have or the location or information on their certification placard or even know that the tire is an ST vs an LT, what are the chances an insurance adjuster will know these differences when they might only see an RV once a year.
If we are just talking a few hundred or thousand $ property damage claim how much effort will the Insurance Co go to if they want to try and make a case that the RV isn't covered.
When was the last time anyone had a claim denied because the RV or car or truck had an overloaded tire? or overloaded axle? or under-inflated tire?
Dollars to donuts most claim adjusters don't know there even is a difference between a P, LT, ST or "Eurometric" tire.
You do realize that there are a number of RVs out there with "special letters" on file at NHTSA indicating the load allowed on a specific tire is not the load marked on the tire? There are tires out there of size STxxxxxx that are marked with non-standard max load yet no information has been given to the RV owner that they would be required to purchase the exact brand, size and design to meet the cert placard.
I think we are giving the insurance adjusters just too much credit for knowledge they don't actually have. Look at how hard it is to even get a correct diagnosis of why a tire failed from a tire salesman.
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Tireman9
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01/21/13 08:19am |
General RVing Issues
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RE: Just some questions on the 16 inch tire upgrade
Weekend Warrior MFG appears to have re-surfaced.
http://www.warriormfg.com/
The "Owner" may still be interested as it appears to be the same person. Seems he has a slogan "Quality through refinement" so who knows he may even want to help out E=mc2.
Who knows maybe the Warrior Co owner may even be happy to learn he made a mistake and would like to avoid repeating it on his current product.
The picture of the cert label that has the VIN & axle & load ratings will be of interest to some.
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Tireman9
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01/19/13 07:10am |
Fifth-Wheels
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RE: Just some questions on the 16 inch tire upgrade
E=mc2
If FastEagle is correct and your placard does say tires are rated at 2540# LR-D and the axle is rated at anything higher than 5081# then I would be really interested is getting a picture of your placard.
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Tireman9
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01/18/13 07:38pm |
Fifth-Wheels
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RE: Just some questions on the 16 inch tire upgrade
Okay so it appears I left some things out, sorry bout that. I currently am running 3- 225/75/15's load range D and 1- 225/75/15 load range E. The previous owner clipped a curb and had to replace a tire. I am running on 5200 lbs axles and as far as the weight on each tire, I do not know. I have only had the trailer for 3 weeks and we don't even have dishes in it yet. I am planning on calling Scott at trailertireandwheels, but I haven't found the time yet, that four letter word keeps getting in the way of my fun. WORK.
There are instructions HEREon how to get the individual tire loads.
You set your inflation for all tires on an axle based on the heaviest tire load for that axle.
I recommend that you use the "dual" tire load to know the max for that tire.
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Tireman9
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01/18/13 04:18pm |
Fifth-Wheels
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