allen8106 wrote: Copied from Goodyear bulletin PSB #2011-13 dated May 18, 2011
Many trailer manufactures establish the recommended tire inflation pressure based on the 65 mph (104 km/h) rated speed for ST tires. In these cases, the ST tires should be inflated 10 psi (69 kPa) higher than the trailer placard for speeds up to 75 mph (121 km/h) (wheel must be rated for this higher inflation pressure). If the trailer manufacturer’s placard specifically states that the cold inflation pressure is suitable for speeds above 65 mph (104 km/h), no additional inflation pressure adjustment is required.
But then again, there is the issue of exceeding the max inflation pressure listed on the sidewall of the tire. Most of the time the trailer manufacturer already has you inflating to the maximum pressure anyway -- so this is a help to virtually no one.
Just an FYI: In the world of tires, there are exceptions to the rules, and this is one of them. Besides, if you look at the sidewall of an ST tire, it will say "Max Load XXXX at YY psi". That is NOT a statement for a maximum pressure, but it is a statement for maximum load.
allen8106 wrote: Copied from Goodyear bulletin PSB #2011-13 dated May 18, 2011
Many trailer manufactures establish the recommended tire inflation pressure based on the 65 mph (104 km/h) rated speed for ST tires. In these cases, the ST tires should be inflated 10 psi (69 kPa) higher than the trailer placard for speeds up to 75 mph (121 km/h) (wheel must be rated for this higher inflation pressure). If the trailer manufacturer’s placard specifically states that the cold inflation pressure is suitable for speeds above 65 mph (104 km/h), no additional inflation pressure adjustment is required.
But then again, there is the issue of exceeding the max inflation pressure listed on the sidewall of the tire. Most of the time the trailer manufacturer already has you inflating to the maximum pressure anyway -- so this is a help to virtually no one.
Just an FYI: In the world of tires, there are exceptions to the rules, and this is one of them. Besides, if you look at the sidewall of an ST tire, it will say "Max Load XXXX at YY psi". That is NOT a statement for a maximum pressure, but it is a statement for maximum load.
Good info. This is easily misunderstood. Thanks for clarifying it.
allen8106 wrote: Copied from Goodyear bulletin PSB #2011-13 dated May 18, 2011
Many trailer manufactures establish the recommended tire inflation pressure based on the 65 mph (104 km/h) rated speed for ST tires. In these cases, the ST tires should be inflated 10 psi (69 kPa) higher than the trailer placard for speeds up to 75 mph (121 km/h) (wheel must be rated for this higher inflation pressure). If the trailer manufacturer’s placard specifically states that the cold inflation pressure is suitable for speeds above 65 mph (104 km/h), no additional inflation pressure adjustment is required.
But then again, there is the issue of exceeding the max inflation pressure listed on the sidewall of the tire. Most of the time the trailer manufacturer already has you inflating to the maximum pressure anyway -- so this is a help to virtually no one.
Just an FYI: In the world of tires, there are exceptions to the rules, and this is one of them. Besides, if you look at the sidewall of an ST tire, it will say "Max Load XXXX at YY psi". That is NOT a statement for a maximum pressure, but it is a statement for maximum load.
In the world of government regulations "recommended tire pressure" is the "correct" tire pressure. Therefore, the tire placard/certification label depicts the correct tire pressure. So, the vehicle manufacturer cannot be held accountable for any GY tire failures when the tire pressure has been increased for speed. Maybe that's why GY is so prompt in paying for vehicle damages. And, remember, Carlisle only recommends 60 MPH for their radial ST tires. Would it be wise to go beyond that when Carlisle will not warrantee them once it’s determined excess speed contributed to a failed Carlisle tire?
Bottom line...Those of us that do not have access to industry standards should leave such things to the vehicle manufacturers to sort out and depict on the vehicles and in their individual vehicle owner's manuals. After all, They built it.
As this thread winds down I want to insert a little food for thought.
I belong to just about every internet forum that has active tire threads. I don’t use the same name on all of them for the obvious reasons. I don’t attract much warm sentiment. Most posters are already angry about tire failures and have a mindset, difficult, at times, to penetrate.
Having worked as an aircraft mechanic for more than 40 years I’m a pretty good study of mechanical things and try to turn over all the stones before coming to any conclusions.
Of the thousands of posts I’ve read over the past 5+ years I can confidently say less than 10% of those posters took the time to investigate the cause of their tire (s) failure (s). Because the vast majority of RV trailers have ST tires as OE they get the brunt of the criticism.
In the early to mid 2000s some of the mass producers of RV trailers used various LT tires. Their failures were very similar to those suffered by their cousins the ST tires. As the toy haulers have grown in popularity so has their size. Many now have triple axles and top out at somewhere over 18K GVWR. So have the spacious 5th wheels with some now using axles with 8000# GAWR.
In pops the 16” LRG LT tire that is really a ST tire in disguise with a 75 MPH speed rating. A strange thing has happened with this tire and it’s primary manufacturer. Whenever a failure is reported to them they pick-up all the costs and the failed tires. The consumer get’s no feed back but the bucks make them happy.
Early on in our venture into full time RVing we did over 100,000 miles and 43 states and a couple of CDN provinces in less than five years. We used a lot of tires and had just about every kind of tire failure, catastrophic or otherwise. None of them were ever determined to be caused by material failure or rim failure. They were all ST tires and we still use them - not the same brand. We are now 520# per tire above what our OE tires were rated. Since 2008 we have had two failures. One was completely destroyed. The steel valve stem was missing. The other sustained a cut sidewall in a construction area on the city streets of Rochester, NY.
So, the bottom line. Is the China Bomb Syndrome Valid? There have been zero recalls for ST tires.
People will say they have always done everything right and still had numerous failures. My question to them is, were they OE tires? None of us know the history of OE tires and just how much abuse they sustained before we took better care of them.
Those out there with tire problems, use a healthy dose of skepticism when taking advise from self anointed tire experts. When they claim to know more that industry insiders about specific tires and their uses, don't just follow the blindly. Perhaps they are receiving compensation of some form to promote an inferior product.
If a particular type of tire fails repeatedly, perhaps you need to find another direction. 22 tires is 9 years on the same rig? That is like burying your head in the sand refusing to listen to common sense. Strict obedience to government guidelines and recommendations? It is well known that Uncle Sam does not always know best. Those documents that others wave around are written by lawyers to protect corporations not the end users.
Think about what you are about to do. If you are about to replace your failed component with the same thing, what are the odds that it will fail in just the same manner(22 tires in 9 years)?
Keith
Keith, Gloria & Charlie(Spoiled Rotten Boston Terrier)
2010 Damon Astoria 3470
2012 Jeep Grand Cherokee Overland
USAF 1968-1976 Viet Nam Veteran
So, the bottom line. Is the China Bomb Syndrome Valid? There have been zero recalls for ST tires.
FastEagle
FE has made a key observation "zero recalls", but the reason for no recalls has nothing to do with the quality or possible lack therof of the tires.
As FE and CapriRacer know, if people do not file proper complaints to NHTSA there is no reason or justification for NHTSA to initiate an investigation and with no investigation there will be no recall.
Having reviewed a few of the complaints I could find on the NHTSA site, I saw incorrect or missing tire size, incomplete or missing DOT serial, incorrect or missing tire manufacturer information, and no documented scale loading of the tires.
NHTSA is not going to start an investigation based on an owner relating how upset the co-pilot is or the fact the owners were on their way to grandma's house or were otherwise inconvenineced.
If you review the statements on this thread on the number of tires that have failed you will see the lack of complete statement of facts. A lot of complaining but few facts.
It is well established fact that over half of the trailers that do get weighed have one or more component overloaded. This is the easy and perfect argument from the RV dealer that it is not the tire's fault but the owner that overloaded the unit. Now before you take issue with what I have said please review the facts, review the complaints on the NHTSA web site, review the complaints on this and other threads and see if you can find any that provide:
Complete and correct tire size info
Complete DOT serial
Statement of when and how the individual tire loads were confirmed
Pictures of the failure. In focus close-ups are of great value.
Date of purchase of the RV or of the tire if a replacement
Minimum inflation and frequency of checking
Does the RV have TPMS
Honest statement of the max speed driven
Was the tire ever repaired
Name of dealer that inspected the failed tire
Who has the failed tire and is it available for further examination
Number of miles the tire has been driven.
RV VIN
I have seen recalls started with as few as five well documented complaints. I myself initiated the actions that led to a recall based on an examination of two tires. BUT the key fact is that the information was accurate and well documented.
You can learn more if you visit my tire blog RVTireSafety
In my opinion as a QS9000 and ISO/TS 16949 Quality auditor the word "Quality" does not appear to be in the RV industry dictionary.
There have been numerous failures from day one with the ground-up LT235/85R16G tires designed for trailer service. They are almost exclusively used on 7000# axles and should have the load capacity to live out their expected life expectancy but are falling short of it. The leading manufacturer has made at least one major attempt at resolving the problem with limited success.
What do you guys think about that steel cased tire? I’ve wondered about it’s regrooveability feature. Even though it has shallow threads it still has the extra tread depth to allow regrooving. Is that presenting a heat problem when the tire is near it’s operational limits? Do you think regrooving them early would help in extending their life expectancy?
I have 2 tire issues that just surfaced today. Since we have the tire tech folks here see if you can point me in the right direction of the problem. I do not yet have a blow out and I'm trying to keep it that way.
Today I was doing some suspension work and the left rear tire looked very rounded. At 1st I thought it was an illusion. So I went to jack up the camper. I have 4 jack stands and I mark them so they are all extended the same height and I have used them on this setting many times. The left rear tire will not clear the concrete on this setting. It drags real hard. H'mm OK raised all the stands up 1 click (about 1")
Then I put a straight edge across the tire and looked at it. See here
The left rear tire on the TT and at the 3:00 position. Looks rounded and high in the center.
So I went to the 3:00 position between the front and rear. Not as bad here but still has some round to it.
Then to compare it to the left front tire that seemed OK otherwise.
It was not a conclusive check on the camper so I did some more looking on the ground.
The left rear tire with a square up to it. On one end.
Then tried to measure off the first tread. It is about 1/8"
Then went 180 degrees to the other side. This side looks more round.
And measures closer to 3/16"
So I compared this to the left front tire. This one seems to have more round on the ground then I saw on the trailer. But was about 1/8". Sorry for the fuzzy pic. It is hard to show the round.
Then I did the tell all. I measured the OD of the tire of all 4 of them.
I have 3 tires that have a OD circumference of 90".
Then I have this left rear tire at 91". It is bulging in the center more then the other 3. It may not be 360 degrees around as bad. Hard to tell. I have a pi tape at work I can get this to thousands if needed but the tape measure found the 1" difference.
I am suspecting something let loose inside this tire and it needs to go before I end up with a blow out.
Here is some info on this setup.
- Axle weight scaled at 7,660# with no water. When I fill the fresh tank over the front axle it adds 266 # more axle load.
- I have 6,000# axle tubes and 5,000# springs. TT is 10,000# GVWR
- Tires are ST225/75R15 Load range D - Denman Express radials made in Mexico.
- Tire pressure is 65psi. Check at the start of every trip religiously.
- LRD tires have 2,540# load at 65 psi. X 4 tires = 10,160# of tires agasint a scaled axle weight of 7,926#. Or 2,234# of reserve capacity.
- I only tow up to 60 mph. The only time this rig has hit 68 to 70 was passing a semi on very rare occasion. This is approx 2 minutes worth and may only have been 3 to 5 times in the life of this tire.
- Tire DOT date is 2908. Tires installed 3-28-09
- Tire has slightly less then 11,000 miles on it. I can get the exact if needed. Log book is out in the truck.
- I have weighed the left and right side of the camper. The slide side (left) is approx 350 # heavier.
- Trailer has shocks on it but only for the last year.
- Tires have balancing beads in them but only for the last year.
- This tire have never been patched or leaked air.
- Axle alignment within Dexter specs when tire installed new.
- Towing has been on the east coast. OH, PA, MI, NY. We do winter camp. Towing has been always above freezing.
- I did slightly compress the side wall about 6 months after it was put on. Pulling into the dump station and I just kissed this high up curb. I stopped instantly and backed out of it. This was not a hard hit, but it happened. A slight burnish about 6" long on the side wall. Cannot find it now. Was going 5 to 8 mph at the time. That was approx 8,500 miles ago.
- Tires are cover with white tire covers when stored at home.
- While this rear tire is bulging the others look the same but can see some level of slightly round to them. Do not know if this is normal or not. Hoping the other are not progressing to this.
- This is what they looked like new. Yes I was tracking the wear with a caliper. This was base line. Had to do with my axle alignment I did.
- Here is a wear check a few months after install. The tire face looks more flat.
OK thoughts? Something is not right with this tire and my gut tells me get ride of it now, put the unused spare (bought same time) on and buy a new tire for the spare. It will be a Maxxis ST as Denman is no longer.
I would like to learn what went wrong or what I did to cause this.
I have my own tire machine and will demount the tire for inside inspection when the new spare comes in.
Thanks
John
I'll post the 2nd question in the next reply. It has to do with cracks in the other tires.
* This post was
edited 04/21/12 07:48pm by JBarca *
John & Cindy
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10
CC, SB, Lariat & FX4 package
21,000 GCWR, 11,000 GVWR
Ford Tow Command
1,700# Reese HP hitch & HP Dual Cam
2 1/2" Towbeast Receiver
2004 Sunline Solaris T310SR
(I wish we were camping!)
I had asked about tire cracks before and did not get a definitive answer on what is tolerable and what is not. Today when I had all 4 tires off and I looked real good at them.
Here is one from the right side. This is not the problem bulging tire in the reply above. I am starting to get fine side wall cracks and a few splits in the tread.
Here is the DOT date
Some of the side wall cracks. They are real fine at this point but at the 4 year mark they are showing up.
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Pulling into the dump station and I just kissed this high up curb. I stopped instantly and backed out of it. This was not a hard hit, but it happened. A slight burnish about 6" long on the side wall. Cannot find it now. Was going 5 to 8 mph at the time. That was approx 8,500 miles ago. 
