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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Let me see if I understand correctly.
You say that an ST tire needs a 15% reserve and should not be loaded beyond 85% of sidewall capacity. Also, you indicate that the LT tire can be used at 100% of it's sidewall capacity.
If this is true, then a lot of manufacturers of RV's are doing their customers a disservice by putting underrated tires on their vehicles. One that comes to mind is JAYCO that still installs 16" load range "D" ST tires with a 3000# load capacity on rigs with 6K axles. Don't believe me? Go to your nearest dealer and take a look.
Keith
Or most Montana's with GAWR OF 6750 and tires rated to 3420. Do the math 90 full pounds of extra capacity per axle. Chris
The RV show at the Jacksonville, FL Equestrian Center opened today. It was also half price day for seniors so we drove out for a look see.
Here is one that confirms none of the major heavy fiver trailer manufacturer's give a hoot about reserve load capacity in their OE tire selection.
Here is a picture of a vehicle tire placard. It’s self explanatory.
Tire Placard
The nice clean tires were easy to read. Goodyear Marathons
rated at 3420# at 80 psi. Isn’t that just GREAT?
FastEagle
p.s. This one was not much better but it did have a little higher rated tire at 3520# at 80 psi.
Tire Placard
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FastEagle
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02/09/12 07:08pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
CapriRacer,
There is a lot of credence placed on the fact that similar LT tires weigh much more than a like sized ST tire. Because of the extra weight the supporters beleive it has to be stronger and support more load capacity than advertised. I’ve tried on numerous occasions to logically explain how that happens but because I lack the credentials you possess my logical postings are sternly argued down.
The most popular argument comes from those that support the use of the LT235/85R16E tire with an all steel casing, extra sidewall materials for protection from curb scuffing, an extra steel belt and the ability to be retreaded. It’s a mileage tire and weighs 55.8#.
In the ST corner comes the ST235/85R16E. It tops the scales at 39.5# and has a shallower tread - it’s not a mileage tire or retreadable - it’s basic construction is a couple of steel belts with - maybe - some nylon caps and polyester sidewall cording. Surely the density of the rubber materials are much lower on the durometer scale than that of the retreadable mileage tire.
From the formal instruction I received on aircraft tires it was stressed that a tire’s strength is derived from it’s basic construction, not the tread or other frills.
I know others along with me would like to have your professional opinion.
FastEagle
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FastEagle
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02/08/12 10:23pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
I'm a little confused. Do you mean that your have weighed your trailer and the tires are running at 88% of their rated load?
Yep! I weigh it all the time. For this Florida trip we have 11,300# setting evenly on our two 6000# axles. My 3520# load capacity tires are aired to 80 psi (cold) and that gives me somewhere around 20% in excess load capacity reserves.
FastEagle
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FastEagle
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02/08/12 09:33pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Yesterday while visiting a local RV trailer dealership........I inspected the tires. They were in fact ST235/80R16E rated at 3520# at 80 psi.......
My book says this ought to be 3420# at 80 psi. It might to well to check out again!
- later addition - I looked up Kenda ST235/80R16 LR E and the folks selling these are quoating 3500# at 90 psi.
........Tire Placard Info
FE, please, please go back and see what it says on the sidewall of those tires. Because if it says 3520# @ 80 psi, then technically the vehicle manufacturer is a whisker within the limit.
But if it says 3500# at 90 psi, then the vehicle manufacturer is outside the standard - and technically in violation of the law.
........By the way, I still use ST tires. I could never determine any of my failures were caused by defective tires and once I got above 12% with my actual load capacity reserves my failures quit. I’ve been using the same name brand - from china - since 2006 and I’m on a second set.
FastEagle
I'm a little confused. Do you mean that your have weighed your trailer and the tires are running at 88% of their rated load?
And before I leave this post: I support the point that FE is trying to make. That trailer manufacturers are at the source of this problem. I'll bet that the if that particular trailer was filled in a normal fashion, the GVW would be exceeded.
I know that documents will lag behind new production and that's why I took pictures and visually checked all the weights and pressures. So I still stand behind what I said in my posting.
Here is another picture to ponder.
Tire and rim matching
FastEagle
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FastEagle
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02/08/12 09:15pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Yesterday while visiting a local RV trailer dealership to shop in their well stocked store we saw an attractive - full body paint - fiver on display and on our way back to our truck decided to check it out. Those of you that know my writings wont be surprised to know that my first stop was at the vehicle labeling information. Then I took a look at the installed tires.
Here is an example of what perspective RV trailer buyers (experienced or first time) will find on a new trailers labeling. After reading the tire and vehicle weight information depicted on the placards - referenced below I inspected the tires. They were in fact ST235/80R16E rated at 3520# at 80 psi. The 7Y manufacturers code indicates they are Kenda tires made in China.
This is a large trailer with enough extra storage compartments to carry well over the maximum load described on the labeling. It is more than a common occurrence to find similar UNDER RATED tires on just about any RV trailer manufacturers products. I’m not singling out a brand here, it just happened to be there.
Down the road the buyer has an above average chance of having serious tire problems with the configuration the manufactured has provided and the dealer has passed on.
There are a number of problems that will confront the new owner of such an equipped trailer. Not obvious but factual is compliance with the 7000# axle requirement. There are other ST tires with the exact size description that will only list 3420# of load capacity on their sidewalls. That could easily be overlooked by an inexperienced installer and surely by the vehicle owner. Carrying a rim/tire assembly from the above trailer into so-and-sos tire shop and asking for a LT tire replacement could result in getting a LT235/85R16E replacement - “it’s a LRE tire”.
Those are just a few examples that confront RV trailer owners seeking replacement tires for their failed OE tires.
Tire Placard Info
If this thread or any like it about tires for the RV trailer needs a direction to follow it really needs to present the reader with acceptable and safe solutions. It’s too late to point fingers when your setting on the side of the road with a couple of failed trailer tires. I’ve had a lot of experience doing just that and it’s not fun, but it will help keep you fit.
By the way, I still use ST tires. I could never determine any of my failures were caused by defective tires and once I got above 12% with my actual load capacity reserves my failures quit. I’ve been using the same name brand - from china - since 2006 and I’m on a second set.
FastEagle
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FastEagle
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02/08/12 10:23am |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Do you recommend using any tire treatment chemicals if so what and why, if not why? The obvious would be to keep the tires covered, and not park on dirt or wet ground. Anything else to prolong tire life?
Thanks in advance!
Nathan
I know that there are treatments I would not recommend. Those are the types that dissolve the waxes that migrate to the surface to form a barrier to oxydation. You can tell these types because after you apply them, you get a black mark on your finger when you rub the tire.
Personally, I would stay away from tire treatments, but I don't have the chemistry background to be definitive.
Michelin has them.
From The Michelin Man
FE
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FastEagle
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02/07/12 10:02pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
And here's the document it comes out of:
Goodyear Databook
Interestingly, this is straight out of the standards manual. However, there is a similar statement in the standards manual for ST tires that Goodyear doesn't put in this pdf file.
Look elsewhere in this document and you'll see what I mean about maximum pressure being a little more flexible than you might normally think. Like Page 2 Table 1.
I think GY has misrepresented the ST tire by including it in this P/LT document, that, in-itself, is out dated and surely not in compliance with rulings that were approved and adopted in 2007. I think the ST tire falls into the same category as the low profile truck trailer tires and cannot be manipulated beyond it's maximum sidewall pressure.
FastEagle
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FastEagle
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02/07/12 09:54pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
The most important point of what I am saying is that to reduce the risk of a tire failure, the best direction is raising the load carrying capacity of the tire.
Now you just got into my ball park. All my writings aim at that exact conclusion. RV trailer tires - whatever design - NEED reserve load capacity. I recommend 12% but stress an even higher 15% above GAWR. It also coincides - as you well know - with the RMA recommendation that was not approved in the 2007 rules making secession.
FastEagle
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FastEagle
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02/07/12 09:40pm |
Tech Issues
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RE: Trailer Tire Rotation
Unless you're a high mileage user I don't think so. If they last long enough I do mine from side to side and front to back every 6/7000 miles because of road camber.
FastEagle
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FastEagle
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02/07/12 03:08pm |
Tech Issues
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RE: Might as well ban them all
Why was the ST vs LT tires
thread closed. I hesitate to bring this subject up - given that a previous thread went on so long and was eventually closed - but........
Perhaps I can help folks understand what may be going on between these 2 types of tires. It was clear in that closed thread that there are some mis-conceptions.
Ya' see, I am a tire engineer with a major tire manufacturer - over 30 years in the business. I've got quite a bit of insight into how this works.
Is anyone interested in reviving the discussion
All of the posts I read were pretty much spot on as far as being on topic, and if they strayed, it was the OP that was willing to answer, and he should of been able to decide what was on HIS topic and what wasn't!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
QUOTE:
Disregarding the several usual members that don't like any kind of moderation, what is occurring in most of the tire threads is that there are a handful of members that take over the threads. Then the next step is they begin attacking each other and any that oppose them. At that point Frank and I start getting all kinds of notifies (most justified). It's a no win situation. We delete the out of line post and then have to either edit or delete all the posts quoting it. It takes a lot of time and is very discouraging.
We don't have any way of merging threads/posts as someone suggested so that is out.
We can let them run and ignore the notifies or try to control them to some degree which is the path I have chosen. If I had a separate sub-forum for them, I would probably opt to move them all there and let them run but there is no programming time available.
Admin
RV.net
END QUOTE:
FE
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FastEagle
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02/07/12 01:34pm |
Fifth-Wheels
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RE: Might as well ban them all
CapriRacer has posted in Tech issues - today.
FE
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FastEagle
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02/07/12 10:29am |
Fifth-Wheels
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RE: Tire Load Ratings
Many of the Special Trailer (ST) tire manufacturers require their tires to be aired to the maximum amount of pressure molded into the sidewall. They will not provide graduated load inflation charts, only the maximum required as depicted in the following reference.
Tire Chart
Maxxis - load inflation chart posted above by another poster - allows manipulation of the air pressure to set load capacities but they only support what the vehicle manufacturer recommends.
FastEagle
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FastEagle
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02/07/12 10:00am |
Tech Issues
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RE: ST vs LT tires
In the tire threads here on RV.NET, we see a lot of controversy about replacing ST tires (any ST tire) with LT tires. Many first time posters are of the opinion that a LRE ST tire can be safely replaced with a like sized LRE LT tire.
Are you saying, from an engineer’s point of view that is an acceptable replacement tire scenario? Is the real strength of the LT235/85R16E tire equal to the (smaller) ST235/80R16E tire?
The tire industry constantly polices itself. Of all the SOP manuals I’ve read, from all of the major brands, none, approve of violating the vehicle tire placard and have made it a point to put strict compliance “cautions” and “safety warnings” in their manuals. Some will even refer to the NHTSA safety standard (s) where it is a prominent statement to use replacement tires with equal or greater load capacities found on the vehicle tire placard. Vehicle owner’s manuals will also mime the NHSTA standard.
FastEagle
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FastEagle
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02/05/12 11:36am |
Fifth-Wheels
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RE: ST vs LT tires
OK . . . I have my 700+ page tire science document sitting on my hard drive waiting to be used for quality assurance of the OP's opinions.
And don't lump Tireman9 and FastEagle into the same category. Tireman9 is a retired engineer who spent years doing failure analysis. FastEagle retired from aviation maintenance where he saw tire use and failure in extreme environments only to enter a life of RVing where he has seen ST tire use and failure in extreme environments (heavy fiver). But FastEagle does his homework and is migrating toward seeing 17.5 inch medium truck tire use in extreme environments (again his heavy fiver).
Still waiting on the OP, and on what FastEagle finally puts on his fiver (and his down the road experiences with them).
WOW! Let's not forget that I was also a ramp manager for Eastern Airlines at airport JAX and a warehouse manager for a rubber house where manafactured rubber materials were transformed into useable items such as gaskets and hoses were cut and fitted for major trucking firms. And let's not forget my stint as a service writer for a Honda dealership.
FastEagle
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FastEagle
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02/03/12 08:20am |
Fifth-Wheels
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RE: ST vs LT tires
I hesitate to bring this subject up - given that a previous thread went on so long and was eventually closed - but........
Perhaps I can help folks understand what may be going on between these 2 types of tires. It was clear in that closed thread that there are some mis-conceptions.
Ya' see, I am a tire engineer with a major tire manufacturer - over 30 years in the business. I've got quite a bit of insight into how this works.
Is anyone interested in reviving the discussion? My feelings won't be hurt if you don't.
Basically, end users are not much interested in all the rigmarole involved with tire manufacturing and design. The end product and it's cost are paramount.
What these tire threads really need is a jolt from user experts with credentials. Someone that can tie all the regulations together and present a user package that is understandable and most of all, ACCEPTABLE.
Give them a tire that will suit their expectations of long life at a low cost and you'll have a returning customer.
A simple explanation such as "you run your tires too long underinflated" or "overloaded" or maybe you were "speeding" will never be an accepted answer here, because, don't you know, none of that happened.
FastEagle
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FastEagle
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02/02/12 09:42pm |
Fifth-Wheels
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RE: Duravis R500 HD Tire Anyone using them
EDITED:
pcm1959 wrote: Interesting. I can't find the load rating in pounds for them. I am looking for a replacement for my Duro 235 85R16 tires on my fiver. The only other tire that comes close in capacity to the Duro is the Goodyear G614. They are running $1600 or more out the door in my area (N FL). phillip
*******************************************************************
DURO tire info.
DURO Tires
Tire Size
Load Inflation
FastEagle
**************************************************************
Another edit:
Since 2007 there have been a total of 18 complaints filed with NHTSA about Duro tires. They can be viewed by using the web site below.
Duro Complaints
FastEagle
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FastEagle
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02/02/12 10:39am |
Fifth-Wheels
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RE: trailer tires for 5th wheel
Tire Safety
Load Capacity
FastEagle
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FastEagle
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01/31/12 08:26pm |
Fifth-Wheels
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RE: trailer tires for 5th wheel
Ever wonder why ST tire users expect mileage results from their tires? Their manufacturers don't ever tout them as mileage tires. Their design suggests just the opposite. Nothing in their warranties would indicate mileage expectations. Their warranties just say to replace them when the tread wear gets down to 2/32" or less.
FastEagle
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FastEagle
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01/31/12 07:57am |
Fifth-Wheels
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RE: trailer tires for 5th wheel
Wellllll I guess I'm gonna stay right here on RV.net since we don't seem to have the same problems other forums have. :B
This is not a model specific forum. Even with a Keystone Everest they will not let me on the Montana forum. However, they do post my tire blog for viewing. Other model specific forums are not as strict about membership and I belong to most of them. Montana is unique because they have been number one in sales for years and there are A LOT of them.
FastEagle
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FastEagle
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01/30/12 07:46pm |
Fifth-Wheels
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RE: trailer tires for 5th wheel
See page 61
If you read my postings why in the world would you think I have not researched that tire?
What I said is, I have to run the ST tires at max sidewall pressures as opposed to what I can run the Yoko tires at. Less pressure, more sidewall flex. I'll not try my math out on how much. At 3400# load capacity they will have 13% in load capacity reserves above my GAWR and that's above what I recommend.
FastEagle
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FastEagle
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01/30/12 11:51am |
Fifth-Wheels
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