I would like some tire help

[Lance M]

Originally Posted by BlackAces

Can you show us a reference that supports replacing Original Equipment ST tires with LT tires? All of the major LT tire manufacturers see that as a misapplication of their tires.

BA

No they don't. That's not true at all.

[AWCHIEF]

Just another Internet myth often repeated but never proven.

[BlackAces]

Originally Posted by Top

No they don't. That's not true at all.

Name one and I'll try and show you where they say it.

BA

[BlackAces]

Originally Posted by AWCHIEF

Just another Internet myth often repeated but never proven.

How are the Original Equipment (OE) tires for your trailer selected?




What is a factual answer for that Question? Not being in the RV trailer manufacturing business, I don’t know. But I do know what the regulations say. Those regulations are directed at RV trailer manufacturers. The major misunderstanding or misconception by many readers of those regulations is about how they can be applied. Just because you have read them does not mean you can apply them differently than a vehicle manufacturer or a tire manufacturer practicing approved tire industry standards.

Regardless of your personal knowledge of the industry and how it works, OE tire selection and fitment is the sole responsibility of the vehicle manufacturer. Once a vehicle is sold to a customer that customer/owner becomes responsible for all subsequent tire replacements.

This is a very basic statement that sets the stage for all tire replacements after a vehicle has been sold. “The size designation and the recommended cold inflation pressure for those tires such that the sum of the load ratings of the tires on each axle is appropriate for the GAWR.” That’s a trailer builders requirement. They must post it on the trailer’s certification label. It is the minimum tire size and load capacity - by inflation pressure - for the OE tires.

In pops the tire industry. They build tires for all sorts of situations. They are not going to countermand vehicle manufacturer OE tire selections. This is their basic statement for replacement tires; “The load carrying capacity and inflation pressure capability of the replacement tires must always equal or exceed the load carrying capacity and inflation pressure capability of the original equipment tires.”

[Lance M]

Originally Posted by BlackAces

Can you show us a reference that supports replacing Original Equipment ST tires with LT tires? All of the major LT tire manufacturers see that as a misapplication of their tires.

BA

Oh, here's a reference for you-

[FishinHatteras]

Black,
I think you answered your own question with this statement:
“The load carrying capacity and inflation pressure capability of the replacement tires must always equal or exceed the load carrying capacity and inflation pressure capability of the original equipment tires.”

Am I understanding your post in that you believe it is incorrect to put a different type of tire on your rig?

Why would AS put them on their Eddie Bauer editions, but consider them bad on other similarly sized, and weighted TT?
Just want to make sure I understand which side of the equation you are arguing.
Gavin

[J. Morgan]

Life lesson 136

"They" (the so called "authorities") often say things that are not so.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[BlackAces]

Originally Posted by FishinHatteras

Black,
I think you answered your own question with this statement:
“The load carrying capacity and inflation pressure capability of the replacement tires must always equal or exceed the load carrying capacity and inflation pressure capability of the original equipment tires.”

Am I understanding your post in that you believe it is incorrect to put a different type of tire on your rig?

Why would AS put them on their Eddie Bauer editions, but consider them bad on other similarly sized, and weighted TT?
Just want to make sure I understand which side of the equation you are arguing.
Gavin

Seldom is there a single answer that will fit a replacement tire situation. The major LT tire manufacturers have provisions in their tire warranty packages that disallow replacing OE tires that are from the ST design with LT designed tires. Some will even go so far as to use the information in your trailer’s owner’s manual as justification.

The DOT only allows the trailer manufacturer the leeway to select OE tires. Design is not part of the regulations requirements. The word appropriate is used by the DOT. If the trailer builder decides one design is more appropriate than another design that’s their decision for that particular trailer. If they want to throw a monkey into the mix by using two differently designed OE tires on something they build it’s their monkey to deal with. Maybe AS confused the use of steel cased LT tires designed for trailer service only, with other steel cased LT tires that are not designed strictly for trailer axle service. However the decision was formulated will not effect replacement tire selections for other models fitted strictly with ST tires.


BA

[BlackAces]

Originally Posted by Top

Oh, here's a reference for you-
Attachment 236080Attachment 236081Attachment 236082

The problem with your reference is how did it happen? Was the trailer owner the major contributor responsible for that tire's condition?

Without some sort of expert forensic proof of cause, you may just be showing a tire severely abused.

Here is another example. The condition is normal for severely abused tires on RV trailers.

DSCN0114_1_1 - iRV2.com RV Photo Gallery

BA

[Tireman9]

Originally Posted by Top

Can you cite the reference for #2 please? I'd be interested to read that.

Simply read the various booklets on RV tire application at Goodyear, Michelin and Bridgestone web sites for 75 mph max speed in RV application. Some other MFG have similar. Yes not all MFG say that. I do note than many smaller companies and importers have limited technical knowledge as they are not tire manufacturers just importers or round black things. Some don't even print the correct information for tire size etc.

The 65 for ST is published by US Tire & Rim Association, Tire Rack, Goodyear and others.

check my profile for info on a blog on RV tires with lots of info on tires.

[Tireman9]

Bottom line is that here in the US the vehicle owner has the right to modify their vehicle. Now the smart thing to do is to be sure any replacement part is equal or better than the OE. For tires that IMO that means equal of higher load and or speed capability as well as longer MFG warranty. I have written detailed instructions on the steps needed to ensure you are in fact getting more load and speed capability.

[r carl]

Originally Posted by BlackAces

The problem with your reference is how did it happen? Was the trailer owner the major contributor responsible for that tire's condition?

Without some sort of expert forensic proof of cause, you may just be showing a tire severely abused.

Here is another example. The condition is normal for severely abused tires on RV trailers.

DSCN0114_1_1 - iRV2.com RV Photo Gallery

BA

So why don't LT tires do that?

[J. Morgan]

I have been using LT tires on trailers for over 30 years. I imagine I have about 80 of them sitting on the ground right now.

Even if I thought the wear characteristics of ST tires were acceptable, (I don't) my experience with LT tires says they perform very very well in trailer service.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[BlackAces]

I’m not a champion of ST tires over LT tires. Both have their special niche in the global tire market. They most often get compared with each other because they - like many other tires - look alike.

It’s been my observation that both designs - when used in their niche - will perform to their manufacturers expectations. Misuse and abuse is their primary cause of early failures. Knowing and operating each tire design within the parameters they are designed to operate in is paramount.

The heyday for LT tires being used on RV trailer axles was in years 2004 and 2005. Again, my observation was that they suffered much the same failure rate as ST tires were to later suffer on the same sized axle loads.
The most obvious success for the LT tires used to replace ST tires is when they have exceeded the ST tires load capacity. For instance, the LT235/85R16E has great success when used as a replacement for ST tires on 5200# GAWR axles. It leaves one to wonder if the ST235/80R16D would have had equal success in the same situation.

I spout a lot about the governing body’s regulations and tire industry standards in my posts. Without one knowing the safety factors one cannot apply them. I can post a half dozen current references that say - in part - replacement tires must have equal/greater size and load capacity as the OE tires. And I’ll always get some negative response to that fact. Even from those that are using such tire replacements.
Fitment for RV trailer axles do not require load capacity reserves via vehicle manufacturer recommended inflation pressures. Automotive industry tire fitments do.

Getting too long, I’ll quit.


BA

[mnmhays]

Tire Details - Discount Tire Direct

Not my first choice...but good enough OEM for vintage TTs...

[J. Morgan]

Why I dont like trailer tires. (Taken from the Discount Tire website)


"Mileage;

Trailer tires are not designed to wear out.

The life of a trailer tire is limited by time and duty cycles.

The mileage expectation of a trailer tire is 5,000 to 12,000 miles."

http://m.discounttire.com/dtcs/infoTrailerTireFacts.dos



1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[Magic Carpet]

Read much about ensuring that tires are inflated to tire pressure listed on side of tire when cold. How much can one allow the pressure to increase due to traveling in hot weather without worry of over-inflation?


Sent from my iPad using Airstream Forums

[SteveSueMac]

Magic Carpet - I'm not a tire expert but asked that same question here: http://www.airforums.com/forums/f438...nt-119498.html

I learned that a 10% increase in pressure and 30% increase in temp above ambient (according to TPMS measurements) is fairly standard though everyone's mileage varies.

[r carl]

Originally Posted by Magic Carpet

Read much about ensuring that tires are inflated to tire pressure listed on side of tire when cold. How much can one allow the pressure to increase due to traveling in hot weather without worry of over-inflation?


Sent from my iPad using Airstream Forums

You inflate the tire when its cold and don't worry about it, why would you check it when its hot? You never need to check hot pressure as far as I know, unless it looks low.

[CapriRacer]

Originally Posted by r carl

So why don't LT tires do that?

Originally Posted by r carl

You inflate the tire when its cold and don't worry about it, why would you check it when its hot? You never need to check hot pressure as far as I know, unless it looks low.

I'm combining these 2 posts to answer them in one post.

First, I think there are several reasons why LT appear not to do that.

1) In every instance I have observed, the replacement LT tire size has gone up - and that equates to an increase in load carrying capacity. The rated load is specific to the type of service and the way ST tires and LT tires are rated is different (with the ST tire being rated at a higher load for the same dimensions)

2) ST tires are built by oh, I call them 3rd tier tire manufacturers (with 2 exceptions). I am sure these guys aren't at the cutting edge of tire technology and I wonder what these guy's LT tires would do. I never find out the answer to that question.

3) Then there is the issue of failure rate. If the actual failure rate is on the order of 10% (probably high), then there is a very large population of people (90%) who will never perceive a problem.

Put another way, if a person were to replace 4 tires, of which one was a failure, with 4 new ones, the odds are they will not experience a second failure. Of course, that person will have difficulty understanding that and will insist that any change they made was the difference.

Now, I am NOT saying that ST tires are equivalent or better than LT tires. I am saying there is a lot going on here and it can be difficult to sort this all out. I am merely pointing out what I perceive to be differences.

- AND -

One of the keys in trying to sort out this complex situation is pressure buildup. Pressure buildup is a way of determining if the load carrying capacity is adequate.

So if the pressure buildup for an ST tire (or any tire for that matter) exceeds 15%, then a failure is likely and it would be due to overload/underinflation/excessive speed and not the manufacturer's design or a defect or the type of tire (ST vs LT).