RV.Net Open Roads Forum: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Help and Support  |  Contact

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Revived Trailer Tire Thread (formerly on the 5th Wheel Forum

This Topic Is Closed  |  Print Page  |  Post New Topic  | 
Page of 95  
Prev  |  Next
Sponsored By:
FastEagle

Taylors, SC

Senior Member

Joined: 03/05/2007

View Profile



Good Sam RV Club Member

Online
Posted: 03/03/12 03:34pm Link  |  Print  |  Notify Moderator

NHIrish wrote:

Francesca Knowles wrote:

FastEagle wrote:

"For single-axle trailers, tires can handle 100% of their load rating. For dual-axle trailers, loads must be reduced by 12%. -Goodyear Tire Company."

Now that's an interesting quote for discussion here.

FastEagle

Interesting how neatly they let the Rv industry off the hook there...
Even the tire industry buys in to the undersizing standard!

Imagine how much better it would be in for both tire manufacturers and consumers if the logic in that sentence were reversed:

"For double axle trailers, the TIRE CAPACITY must be INCREASED by 12%"


Which is , ironically, exactly what many folks eventually do.


Not sure this is accurate...I always thought the dual rating meant as in a dually setup????? Why would load rating vary on a vehicle with two axles over a vehicle with one axle. This would effectively mean, for my application, that there are NO G rated tires I can find in 16" that would be suitable for use on my 7000 lb axles...which I have 2 of. Just does not make sense to me.


I read just about everything about RV trailer tires and file all my references. Sometimes I forget where some are stored - LOL. But I found this one.

GY Ref

FE

FastEagle

Taylors, SC

Senior Member

Joined: 03/05/2007

View Profile



Good Sam RV Club Member

Online
Posted: 03/03/12 04:04pm Link  |  Print  |  Notify Moderator

NHIrish wrote:



Not sure this is accurate...I always thought the dual rating meant as in a dually setup????? Why would load rating vary on a vehicle with two axles over a vehicle with one axle. This would effectively mean, for my application, that there are NO G rated tires I can find in 16" that would be suitable for use on my 7000 lb axles...which I have 2 of. Just does not make sense to me.


When a little math is used to see what a safe load capacity would be for LRG G614 tires on two 7000# axles using the recommended 12% reduction by GY you are good to go at 13200# GAW. That’s with all tires aired to 110 psi.

FE

On Edit: Remember, that is a tire manufacturer's recommendation and they are not responsible for setting vehicle tire pressures, the vehicle manufacturer is.

* This post was edited 03/03/12 04:46pm by FastEagle *

FastEagle

Taylors, SC

Senior Member

Joined: 03/05/2007

View Profile



Good Sam RV Club Member

Online
Posted: 03/03/12 04:55pm Link  |  Print  |  Notify Moderator

[quote=ExRocketScientist]

The concept of dual load rating for a tire is not new. Light truck tires have one rating for single use and another for dual use.
Quote:



The reduction in load capacity in the above situation is to off-set road camber. (So the theory goes).

FE

Chris

Shelter Bay, Wa

Senior Member

Joined: 12/19/2000

View Profile



Good Sam RV Club Member

Offline
Posted: 03/03/12 05:03pm Link  |  Print  |  Notify Moderator

FastEagle wrote:

NHIrish wrote:

Francesca Knowles wrote:

FastEagle wrote:

"For single-axle trailers, tires can handle 100% of their load rating. For dual-axle trailers, loads must be reduced by 12%. -Goodyear Tire Company."

Now that's an interesting quote for discussion here.

FastEagle

Interesting how neatly they let the Rv industry off the hook there...
Even the tire industry buys in to the undersizing standard!

Imagine how much better it would be in for both tire manufacturers and consumers if the logic in that sentence were reversed:

"For double axle trailers, the TIRE CAPACITY must be INCREASED by 12%"


Which is , ironically, exactly what many folks eventually do.


Not sure this is accurate...I always thought the dual rating meant as in a dually setup????? Why would load rating vary on a vehicle with two axles over a vehicle with one axle. This would effectively mean, for my application, that there are NO G rated tires I can find in 16" that would be suitable for use on my 7000 lb axles...which I have 2 of. Just does not make sense to me.


I read just about everything about RV trailer tires and file all my references. Sometimes I forget where some are stored - LOL. But I found this one.

GY Ref

FE


Calvin, you should get a job with Keystone and solve the issues with most of their larger trailers with GAWR of 6750 and two Marathon's rated to 3420. Have you contacted them about this terrible tire choice? If trailers came OEM with tires better suited to weight and use, then we would see a lot less tire threads. Chris

* This post was edited 03/03/12 08:26pm by Chris *


My Rig
2001.5 2500 STD CAB AUTO SLT 4x4, CTD 4:10's, Bomb'd to Tow
2005 Cardinal 29WBLX.

Tireman9

Akron, OH

Senior Member

Joined: 08/16/2002

View Profile


Offline
Posted: 03/03/12 08:33pm Link  |  Print  |  Notify Moderator

FastEagle wrote:

ExRocketScientist wrote:



The concept of dual load rating for a tire is not new. Light truck tires have one rating for single use and another for dual use.
Quote:



The reduction in load capacity in the above situation is to off-set road camber. (So the theory goes).

FE


It is not unreasonable to make the argument that tandem axle trailers should use the same load limits as shown for dual tire application. Road camber is just one of the contributing factors.

Still looking for the actual Goodyear document that says 12%. The link provided was to a boat trailer page that had a few erronious statements on it. It claimed that GY said 12 % but I didn't quickly find that in the GY documents.


40 years experience as tire Design & Quality engineer with focus on failed tire forensics.

Google "Tireman9" if you want to learn more on RV Tire Safety

OldGreaser

South Texas

Senior Member

Joined: 02/13/2010

View Profile


Offline
Posted: 03/04/12 05:00am Link  |  Print  |  Notify Moderator

I need to correct an error I made yesterday interpreting FE's reference to the Federal Motor Vehicle Safety Standards. I said that the total GAWR for a trailer must meet or exceed the GVWR with no allowance for pin or tongue weight. That's only the case for a motorhome:

"S10.1 On motor homes, the sum of the gross axle weight ratings (GAWR) of all axles on the vehicle must not be less than the gross vehicle weight rating (GVWR). S10.2 On RV trailers, the sum of the GAWRs of all axles on the vehicle plus the vehicle manufacturer's recommended tongue weight must not be less than the GVWR. If tongue weight is specified as a range, the minimum value must be used. "

Sorry for being anal, but I think this is a really important point. I noticed Tireman had it right in the ensuing posts but still wanted to clear it up.

NHIrish

White Mountains NH

Senior Member

Joined: 07/30/2005

View Profile



Good Sam RV Club Member


Posted: 03/04/12 06:38am Link  |  Print  |  Notify Moderator

FastEagle wrote:

NHIrish wrote:



Not sure this is accurate...I always thought the dual rating meant as in a dually setup????? Why would load rating vary on a vehicle with two axles over a vehicle with one axle. This would effectively mean, for my application, that there are NO G rated tires I can find in 16" that would be suitable for use on my 7000 lb axles...which I have 2 of. Just does not make sense to me.


When a little math is used to see what a safe load capacity would be for LRG G614 tires on two 7000# axles using the recommended 12% reduction by GY you are good to go at 13200# GAW. That’s with all tires aired to 110 psi.

FE

On Edit: Remember, that is a tire manufacturer's recommendation and they are not responsible for setting vehicle tire pressures, the vehicle manufacturer is.


MAN...all well and good, but just how under tired was I with the load range e phony rated Duro tires. That truly is scary. No wonder there are so many tire failures.....


2010 Carriage Cameo 32FWS
2011 Chevrolet 3500 DMAX ECLB
B&W Companion

Diplomacy is the art of saying 'Nice doggie' until you can find a rock



JIMNLIN

Oklahoma

Senior Member

Joined: 09/14/2003

View Profile



Posted: 03/04/12 08:49am Link  |  Print  |  Notify Moderator

If the trailer is a dual tandam axle unit (8 tires) then the reduction in capacity applies in this case just like a dual wheel axle on a truck. The modern tandam axle trailer (4 tires) with a equilizer bar has no need of its tires load capacity to be derated.

Many boat trailers (and other single and tandam axle trailer types) come with P tires. Fed 571 regs says this about P tires capacity on a trailer:

"When a passenger car tire is installed on a multipurpose passenger vehicle, truck, bus, or trailer, the tire's load rating shall be reduced by dividing by 1.10 before calculating the sum ....(snip).

I can't see Goodyear adding another 12 percent reduction on top of the fed required 10 percent reduction on their tires. They couldn't compete with other tire makers for OEM tire replacemnet, if this was the case.


"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers

'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides

Francesca Knowles

Port Hadlock, Washington

Senior Member

Joined: 02/23/2011

View Profile



Posted: 03/04/12 09:19am Link  |  Print  |  Notify Moderator

JIMNLIN wrote:

Fed 571 regs says this about P tires capacity on a trailer:

"When a passenger car tire is installed on a multipurpose passenger vehicle, truck, bus, or trailer, the tire's load rating shall be reduced by dividing by 1.10 before calculating the sum ....(snip).



Sorry if this is redundant...Can/will you post a link to the regs you snip from above?


" Not every mind that wanders is lost. " With apologies to J.R.R. Tolkien

FastEagle

Taylors, SC

Senior Member

Joined: 03/05/2007

View Profile



Good Sam RV Club Member

Online
Posted: 03/04/12 12:16pm Link  |  Print  |  Notify Moderator

Francesca Knowles wrote:



Sorry if this is redundant...Can/will you post a link to the regs you snip from above?


From: FMCSA 571.110

“S4.2.2.2 When passenger car tires are installed on an MPV, truck, bus, or trailer, each tire's load rating is reduced by dividing it by 1.10 before determining, under S4.2.2.1, the sum of the maximum load ratings of the tires fitted to an axle.”

That rule is always a normal part of the SOP for vehicle manufacturers and has already been accounted for on the vehicle tire placards whenever applicable.

FE

This Topic Is Closed  |  Print Page  |  Post New Topic  | 
Page of 95  
Prev  |  Next

Open Roads Forum  >  Tech Issues

 > Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:

© 2014 RV.Net | Terms & Conditions | PRIVACY POLICY | YOUR PRIVACY RIGHTS