Reply
 
Thread Tools Search this Thread Display Modes
 
Old 03-22-2015, 04:04 PM   #57
Rivet Master
 
AWCHIEF's Avatar
 
2006 23' Safari SE
Biloxi , Mississippi
Join Date: Nov 2011
Posts: 8,138
Images: 33
Quote:
Originally Posted by J. Morgan View Post
Does it make me bad if I towed my ST tires in excess of 75 MPH frequently when crossing Texas?






1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow
Your trailer, your life. Thanks for the heads up.
__________________

__________________
MICHAEL

Do you know what a learning experience is? A learning experience is one of those things that says "You know that thing that you just did? Don't do that."
AWCHIEF is offline   Reply With Quote
Old 03-22-2015, 04:37 PM   #58
Rivet Master
 
Currently Looking...
Nowhere , Somewhere
Join Date: Jul 2005
Posts: 6,417
Blog Entries: 2
And then we have those who spend bucks for LT. tires and yet run their tow vehicles too low to get a smoother ride. According to tire posts I have read in the past. No I have no proof of this!! Don't ask. Jim
__________________

__________________
avionstream is offline   Reply With Quote
Old 03-22-2015, 04:41 PM   #59
Rivet Master
 
AWCHIEF's Avatar
 
2006 23' Safari SE
Biloxi , Mississippi
Join Date: Nov 2011
Posts: 8,138
Images: 33
Jim, no problem. Proof is not needed when internet kitchen table engineers get on a roll.
__________________
MICHAEL

Do you know what a learning experience is? A learning experience is one of those things that says "You know that thing that you just did? Don't do that."
AWCHIEF is offline   Reply With Quote
Old 03-22-2015, 04:44 PM   #60
Rivet Master
 
SteveSueMac's Avatar

 
2012 27' Flying Cloud
W , New England
Join Date: Oct 2012
Posts: 5,411
Quote:
Originally Posted by J. Morgan View Post
Does it make me bad if I towed my ST tires in excess of 75 MPH frequently when crossing Texas?


:-)

This does not make you a bad person.

Using a Hensley? Well.....

JUST KIDDING now..... :-)
__________________
SteveSueMac is offline   Reply With Quote
Old 03-22-2015, 04:44 PM   #61
Rivet Master
 
Currently Looking...
Nowhere , Somewhere
Join Date: Jul 2005
Posts: 6,417
Blog Entries: 2
It does seem to be necessary to some who disagree with what is said. Seems to be a growing trend on the forums. We must remember that everything gleaned on the Internet must be looked at carefully. Lots of incorrect stuff there on all subjects. Jim
__________________
avionstream is offline   Reply With Quote
Old 03-22-2015, 05:02 PM   #62
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,813
Images: 12
Some people may like Goodyear Marathon Tires but I can't say much for them. I will let this picture say 1,000 words.

6am in SC the trooper asked me if i had a problem and I said not if you have a patch kit. He did not have a sense of humor.
Attached Thumbnails
Click image for larger version

Name:	Marithon 2.jpg
Views:	477
Size:	113.9 KB
ID:	234755  
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 03-22-2015, 05:11 PM   #63
Rivet Master
 
Currently Looking...
Nowhere , Somewhere
Join Date: Jul 2005
Posts: 6,417
Blog Entries: 2
Not funny, trailer okay? Jim
__________________
avionstream is offline   Reply With Quote
Old 03-22-2015, 05:34 PM   #64
Rivet Master
 
r carl's Avatar
 
Vintage Kin Owner
Lin , Ne
Join Date: Dec 2009
Posts: 2,057
Quote:
Originally Posted by J. Morgan View Post
Does it make me bad if I towed my ST tires in excess of 75 MPH frequently when crossing Texas?






1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow
My Yokohama's have seen 90mph.
__________________
The higher your expectations the fewer your options.
r carl is offline   Reply With Quote
Old 03-23-2015, 06:28 AM   #65
CapriRacer
 
CapriRacer's Avatar
 
I'm in the , US
Join Date: Sep 2012
Posts: 624
Quote:
Originally Posted by gmw photos View Post
First of all, I'm not trying to pick a fight here. Second, I have no dog in this fight anyway because I don't buy ST tires. Having thrown those disclaimers out there, I think the key word in the above quote is "confusing".

Here is the quote from the Goodyear product service bulletin issued to dealers:

"Goodyear Marathon Special Trailer tires, with the “ST” size designation, are speed rated at 65 MPH (105 km/h) under normal inflation and load conditions."

....it then goes on to say:

"If Goodyear tires, with the ST designation, are used at speeds between 66 and 75 mph (106 km/h and 120 km/h), we recommend the cold inflation pressure be increased by 10 psi (70 kPa) above the recommended pressure based on the trailer placard for normal inflation and load conditions."
===============
Now then, to me, the confusing part of this is that the "implication" is the consumer could increase the inflation to 75psi. I suspect that is NOT what Goodyear is trying to say however. What they "are" saying is the inflation can be increased 10 psi "above the recommended pressure based on the trailer placard for normal inflation and load conditions".

In other words, they may be saying you could literally increase the inflation pressure 10 psi above what the load/inflation table states is the acceptable minimum.

So for instance, if the load/inflation table says that you could run 55 psi for the given specific load, then you could run 65 mph at 55 psi. To increase your speed to 75 mph, you could increase the pressure to 65 psi. Further, you cannot assume an increase in load capacity by this pressure increase, only a speed capacity increase.

Hopefully Roger or Barry will weigh in on this, but I personally have not seen a tire manufacturer that "allows" for tires to be inflated beyond the psi stated on the tire sidewall. I will stand corrected on that however if one of the tire engineers say that I am in error on that.

geo
Allow me to start in a different spot.

The load carrying capacity of a tire is affected by a great many things. We're all familiar that tire size (physical dimensions) and inflation pressure have an effect. Those are delineated in the tables.

But there are other things - and generally offered in the form of a different table - or a modification of the table. These separate tables or modifications to existing tables are for conditions DIFFERENT than delineated by the table heading.

For example, a P type tire table is for typical highway speed on relative smooth paved surfaces on softly sprung vehicles. The modification for light trucks is a derating of 10% for more stiffly sprung vehicles on less smooth surfaces at slightly slower speeds (what a pickup truck is normally used for). For the sake of simplicity, trailer application is included in that.

In the case of the ST tire table, the changes for speed could have been done in a couple of different ways: An increase in inflation pressure or a reduction in load - which from a tire engineer's perspective is the same thing - deflection. Higher speeds reduce the load carrying capacity - or stated from the other direction, higher loads result in less speed capability at a given inflation pressure. That is what the notes on the Goodyear load table are about.

BTW, those notes are taken directly from the Tire and Rim Association (TRA) Yearbook load tables - and here is where Roger and I disagree - they would apply regardless of who manufacturers the ST tire. The reason Roger and I disagree is that some manufacturers may not want their tires operated in any condition other than what THEY publish (I presume for legal reasons) - where I am coming at this from the theoretical point of view about how tires behave.

Now let me address the issue of increasing the inflation pressure. If you look carefully, you will see that the the sidewalls of tires state a maximum load - and either a maximum inflation pressure - OR - a pressure where this max load occurs - like this:

Max Load XXXX, Max pressure YY

- OR -

Max Load XXXX at YY pressure.

Note that the first way doesn't say what the relationship is, and the second way doesn't say what the max pressure is.

Side note: Occasionally, some manufacturers will use this form: Max Load XXXX at Max pressure YY. I think this is incorrectly stated, but I am willing to accept they are trying to prevent people from overinflating the tire.

I can explain why it is OK for Goodyear (and the TRA) to specify an inflation pressure increase beyond the max stated in the table, but the explanation involves some engineering concepts that are just too long for a post like this one. (After having written that, I think I will do another post on this subject AFTER folks have digested this one!)

Soooooo, the Goodyear ST tables have included some notes if it is desired to operate at a speed higher than 65 mph that the table specifies.

So, you may say, why is this so complicated. In the case of automobiles, the car manufacturers have done a good job of sizing the tires and defining what is needed for their vehicles - in the form of the vehicle tire placard on the driver's doorpost.

In the case of pickup trucks and SUV's, manufacturers of those vehicles haven't done as good of a job in the past, but as of 2008 have addressed the issue to the same level as the car manufacturers.

But trailer manufacturers are behind. In the past, their tire specifications (size and inflation pressure) were marginal - and in some cases worse than that. Trailer manufacturers do not have the extensive feedback system that car and pickup truck manufacturers have (dealers and the warranty system), so in most cases, they don't know there is an issue. To complicate matters, they slough off tire issues to the tire manufacturer - and the local tire dealers frequently don't handle off brands, so tire sizing issues don't get reported to where changes would be made.

That is why it is important to report tire failures to NHTSA. They are the government agency responsible for safety. They are NOT going to address issues they don't know about. Whether it is the trailer manufacturer under specifying or the tire manufacturer underdesigning, is for NHTSA to investigate.
__________________
CapriRacer is offline   Reply With Quote
Old 03-23-2015, 06:50 AM   #66
CapriRacer
 
CapriRacer's Avatar
 
I'm in the , US
Join Date: Sep 2012
Posts: 624
Quote:
Originally Posted by HowieE View Post
Some people may like Goodyear Marathon Tires but I can't say much for them. I will let this picture say 1,000 words.



6am in SC the trooper asked me if i had a problem and I said not if you have a patch kit. He did not have a sense of humor.
I am sure Roger will look at this photo and do the same thing I am doing.

First, I am not trying to pick on HowieE. I am trying to explain what I see in the photo and how that relates to tire failures.

Notice in the photo that there are strings of fabric coming off the sidewalls. The configuration is typical of a tire operating with little or no inflation pressure - commonly called a *Run Flat*. The question is what caused the tire to go flat.

I notice the tread (and belt package) appears to be in one piece (although we can't be sure if it is in the form of a hoop or in the form of a flat strip) If the tread (and belt package) are a hoop, then it is very likely that there is a puncture - and if we had all the pieces in front of us, that's what we should look for.

If the tread (and belt package) are in the form of a strip (and it kind of looks like it might be), the question is: Did the tire separate on its own or was it damaged such that the tread detached? I'd need a much closer examination to determine that. One possibility is that there was a slowly leaking puncture - and just like the above, it is something we should look for.

Just so we are clear on this, I am not trying to place the blame on HowieE, nor am I trying to absolve the tire manufacturer of blame. I am just expressing that there are things that happen on the road that could cause a tire failure that are just a part of the risk of operating a vehicle on the highway.
__________________
CapriRacer is offline   Reply With Quote
Old 03-23-2015, 08:42 AM   #67
Rivet Master
Commercial Member
 
Ravenna , Ohio
Join Date: Apr 2012
Posts: 690
Quote:
Originally Posted by Top View Post
Sometimes when we feel offended we get a bit touchy, eh?

Steve is talking about the Michelin LTX MS2 P235/75/15XL and the Pirelli Scorpion LT235/75/15 LRD that I linked.

Ya I had a bad day yesterday. My Bad.
__________________
Retired tire engineer (40 years). Write a blog on RV tires.
Tireman9 is offline   Reply With Quote
Old 03-23-2015, 08:53 AM   #68
Rivet Master
Commercial Member
 
Ravenna , Ohio
Join Date: Apr 2012
Posts: 690
Quote:
Originally Posted by HowieE View Post
Some people may like Goodyear Marathon Tires but I can't say much for them. I will let this picture say 1,000 words.

6am in SC the trooper asked me if i had a problem and I said not if you have a patch kit. He did not have a sense of humor.
Here is an analysis of a somewhat similar tire on my blog July 22 2012. It was even on an Airstream so that might satisfy some here.

HowieE, Any chance you have a higher res picture. I see some parts of your tire that may provide a clue but the areas of interest are out of focus.

If you don't have my email (posted on my blog under my picture) I would be happy to do a "visual inspection" but need better quality shot.
__________________
Retired tire engineer (40 years). Write a blog on RV tires.
Tireman9 is offline   Reply With Quote
Old 03-23-2015, 11:29 AM   #69
Rivet Master
 
Currently Looking...
K.C. , Missouri
Join Date: Nov 2011
Posts: 585
Ok forum tire junkies, I stand corrected on my thoughts regarding inflation of Marathon tires. I have been educated by a tire engineer there are some conditions in which a user can in fact inflate a tire to 75 psi, even that tire has 65 psi embossed on the sidewall.
Learn something new every day.
__________________
gmw photos is offline   Reply With Quote
Old 03-23-2015, 12:22 PM   #70
4 Rivet Member
 
Currently Looking...
z , North Carolina
Join Date: Oct 2014
Posts: 262
Images: 7
This is probably one of the best threads I have read on here in quite some time.

Now I have a question or two for those that have pushed the GYM's into the ditch where they belong IMHO, and have moved up to 16" tires please? My MS2's arrived today, rims will be here on Friday...so, my ? is, Did you find that your hitch needed adjustment after the tires were mounted? And finally, how much clearance do you have in your wheel well with the 16" tires mounted?
Thanks everyone for this detailed discussion. I have learned a ton of information, and it's very obvious, ALOT of you guys know WTH you are talking about. Good company to keep!
__________________

__________________
FishinHatteras is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bad Marathon, Bad Marathon ROBERTSUNRUS Tires 45 11-01-2015 04:46 PM
GoodYear Marathon ST Tires and NHTSA 762x51 Tires 31 07-31-2013 07:59 AM
Goodyear Marathon Tires Ins. Man Tires 48 11-13-2011 07:57 AM
Goodyear Marathon Source Jabba Tires 28 02-22-2004 12:16 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 07:58 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.