RV.Net Open Roads Forum: Fifth-Wheels: Tire pressure

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 Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Fifth-Wheels

Open Roads Forum  >  Fifth-Wheels

 > Tire pressure

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Prev  |  Next
Sponsored By:
Planning

Idaho

Full Member

Joined: 04/26/2004

View Profile


Offline
Posted: 06/10/19 08:11pm Link  |  Quote  |  Print  |  Notify Moderator

azdryheat wrote:

Why should my trailer be any different?


Because it is a different type of vehicle with different types of forces impacting the tires. With tires on multi-axle trailers, like RV trailers, the belt (interply) shear forces can be 24% higher than the belt shear forces of identical size, load and inflation tires on a motorized vehicle.

The internal structural forces are different for torque than for high "slip angle" which is the situation in trailer application. Front tires on cars, motorhome or tow vehicles experience slip angle usually in the 1° range while trailer tires are subject to angles in the 10° and greater range. The forces are NOT linear. 10° can generate significantly more shear than 1°.

Here is a large amount of data compiled by tire engineers regarding this issue: http://www.rvtiresafety.net/search/label/Interply%20Shear


2016 AF 29-5K; 2016 F350 6.7, 4x4, CCLB DRW

ChuckSteed

Mtn Home, Idaho

Full Member

Joined: 01/15/2011

View Profile



Good Sam RV Club Member

Offline
Posted: 06/11/19 07:12am Link  |  Quote  |  Print  |  Notify Moderator

Sailun tires are as good as any GY tires made for RVs... personally I run a Geo Star Chinese made G rated 14 ply tire... starting 4th season... r7n them at 105 to 110 psi...

They will continue to perform quite well... GY G614 is a nice tire but not worth the cost factor when a good G rated 14 ply tire will work just as well

If you’ve got money to burn then buy the best....Sailun would be your huckleberry

Planning

Idaho

Full Member

Joined: 04/26/2004

View Profile


Offline
Posted: 06/11/19 11:39am Link  |  Quote  |  Print  |  Notify Moderator

ChuckSteed wrote:

Sailun tires are as good as any GY tires made for RVs... personally I run a Geo Star Chinese made G rated 14 ply tire... starting 4th season... r7n them at 105 to 110 psi...

They will continue to perform quite well... GY G614 is a nice tire but not worth the cost factor when a good G rated 14 ply tire will work just as well

If you’ve got money to burn then buy the best....Sailun would be your huckleberry


I was using the GY G614 16 inch and changed into the Sailun S637 235/75R -17.5, for $178 per tire delivered.

The same GY tire/size would have cost me almost 3 times as much per tire, for the dubious process of obtaining a replacement tire in the event of a covered failure. Dubious since I had already experienced the process once, and it was definitely not "plug n play".

The Sailun tires are substantial in their construction; the sidewall strength is impressive, and the performance has been flawless. They are manufactured under ISO 9000 standards, and when I (soon) replace my TV tires I will be going with Sailuns there as well.

azdryheat

Tucson, AZ

Senior Member

Joined: 03/02/2012

View Profile



Good Sam RV Club Member

Offline
Posted: 06/11/19 04:34pm Link  |  Quote  |  Print  |  Notify Moderator

Planning wrote:

azdryheat wrote:

Why should my trailer be any different?


Because it is a different type of vehicle with different types of forces impacting the tires. With tires on multi-axle trailers, like RV trailers, the belt (interply) shear forces can be 24% higher than the belt shear forces of identical size, load and inflation tires on a motorized vehicle.

The internal structural forces are different for torque than for high "slip angle" which is the situation in trailer application. Front tires on cars, motorhome or tow vehicles experience slip angle usually in the 1° range while trailer tires are subject to angles in the 10° and greater range. The forces are NOT linear. 10° can generate significantly more shear than 1°.

Here is a large amount of data compiled by tire engineers regarding this issue: http://www.rvtiresafety.net/search/label/Interply%20Shear
What I know is I've had two 5th wheels in the last eight years running Michelin truck tires, traveling all over the US in the heat of summer and have yet to have a tire issue. I don't baby my tires and I don't run them at max pressure. My current Michelins are five years old and are wearing fine. So called tire experts can talk about shear and degrees and such but I'll talk from actual tire usage and the 100% reliability of my truck tires. Truck tires are tough and can take the abuse, Chinese trailer tires can't.


2013 Chevy 3500HD CC dually
2014 Voltage 3600 toy hauler
2011 Harley Ultra Limited
2016 RZR 900


fj12ryder

Platte City, MO

Senior Member

Joined: 08/19/2003

View Profile



Posted: 06/11/19 05:41pm Link  |  Quote  |  Print  |  Notify Moderator

azdryheat wrote:

What I know is I've had two 5th wheels in the last eight years running Michelin truck tires, traveling all over the US in the heat of summer and have yet to have a tire issue. I don't baby my tires and I don't run them at max pressure. My current Michelins are five years old and are wearing fine. So called tire experts can talk about shear and degrees and such but I'll talk from actual tire usage and the 100% reliability of my truck tires. Truck tires are tough and can take the abuse, Chinese trailer tires can't.
Looks like a well thought out post, good points until that last sentence. That mis-statement throws the whole post into doubt.

My Sailun ST tires, and almost every other one I've read about have lasted with no issues. Chinese-made and an ST tire, but an excellent tire that I would buy again in a heartbeat.

* This post was edited 06/12/19 08:24am by an administrator/moderator *


Howard and Peggy

"Don't Panic"

JIMNLIN

Oklahoma

Senior Member

Joined: 09/14/2003

View Profile



Posted: 06/11/19 07:16pm Link  |  Quote  |  Print  |  Notify Moderator

Your 17.5" Sailuns have a 6008 lb capacity per tire at 120 psi on a trailer with 7k or even 8k axles.
The 16" Sailun G load range with the 4080 lb or 4400 lb capacity would have been a better fitment.
But you gotta' work with what you got.
Remember some input comes from some that have just a few years pulling a couple of road trailers.

Lots of websites 'splains why we should use max sidewall pressures in a tire on a trailer. However this recommendation works best if the tire load capacity has been fitted to the trailers axle ratings with a 10-15 percent reserve capacity.

So we find some websites that says this when we over tire the trailer such as a 6000 lb tire on a 7k axle;

fifthwheelstreet.com

Step #5..
Selecting the Correct Tire Pressure for Your Trailer
We at Fifth Wheel St. no longer recommend adjusting trailer tire inflation pressure below the maximum load PSI rating molded on the sidewall (and only if the wheel/rim is appropriately rated) regardless of the measured scaled weight of individual tire or axle positions for all multi-axle trailers.

However, we do strongly recommend weighing individual trailer tire positions to ensure none of the axles or tire positions are overloaded. Reports have shown that trailers do not have equal weight across all tire positions. Some RV load configurations may reveal as much as 20% difference between the front and rear axle. This especially true for Toy Haulers. It is possible that mismanaged trailer load distribution will cause one end of an axle or a tire to be overloaded. It has been stated, but never confirmed by any RV Weighmaster, that there are many RVs traveling on the road with at least one tire or axle side overloaded. The only way to ensure tires and or axles are not overloaded is to weigh each tire position on your trailer. Unfortunately, attempting to obtain accurate individual tire position weight is practically impossible at all truck scales.**


"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

Planning

Idaho

Full Member

Joined: 04/26/2004

View Profile


Offline
Posted: 06/11/19 07:46pm Link  |  Quote  |  Print  |  Notify Moderator

azdryheat wrote:

What I know is I've had two 5th wheels in the last eight years running Michelin truck tires, traveling all over the US in the heat of summer and have yet to have a tire issue. I don't baby my tires and I don't run them at max pressure. My current Michelins are five years old and are wearing fine. So called tire experts can talk about shear and degrees and such but I'll talk from actual tire usage and the 100% reliability of my truck tires. Truck tires are tough and can take the abuse, Chinese trailer tires can't.


Anecdote is not the plural of datum.

Planning

Idaho

Full Member

Joined: 04/26/2004

View Profile


Offline
Posted: 06/11/19 07:54pm Link  |  Quote  |  Print  |  Notify Moderator

JIMNLIN wrote:

Your 17.5" Sailuns have a 6008 lb capacity per tire at 120 psi on a trailer with 7k or even 8k axles...Unfortunately, attempting to obtain accurate individual tire position weight is practically impossible at all truck scales.**


Practically impossible once, and never attainable on a repetitive basis (to account for differing load weights and measures).

On my 7k axles, the 17.5 is absolutely overkill, and intentionally so.
I desired more than the stipulated 10%-15% safety margin.

Anecdotally, the trailer overall pulls significantly more steady, and was immediately noticeable in turns and on poor condition interstates.

And I have no quarrel with experience "regarding some that have just a few years pulling a couple of road trailers". Although now retired, not including recreational travel, I have 40 plus years of interstate/intrastate OTR commercial truck and trailer driving with Hazmat, Air Brake, Tank endorsements.

* This post was edited 06/11/19 08:01pm by Planning *

Cummins12V98

on the road

Senior Member

Joined: 06/03/2012

View Profile


Offline
Posted: 06/11/19 10:19pm Link  |  Quote  |  Print  |  Notify Moderator

ChuckSteed wrote:

Sailun tires are as good as any GY tires made for RVs... personally I run a Geo Star Chinese made G rated 14 ply tire... starting 4th season... r7n them at 105 to 110 psi...

They will continue to perform quite well... GY G614 is a nice tire but not worth the cost factor when a good G rated 14 ply tire will work just as well

If you’ve got money to burn then buy the best....Sailun would be your huckleberry


I have “the money to burn” and happy to do so.


2015 RAM LongHorn 3500 Dually CrewCab 4X4 CUMMINS/AISIN RearAir 385HP/865TQ 4:10's
37,800# GCVWR "Towing Beast"

"HeavyWeight" B&W RVK3600

2016 MobileSuites 39TKSB3 highly "Elited" In the stable

2007.5 Mobile Suites 36 SB3 29,000# Combined SOLD

fj12ryder

Platte City, MO

Senior Member

Joined: 08/19/2003

View Profile



Posted: 06/12/19 07:28am Link  |  Quote  |  Print  |  Notify Moderator

ChuckSteed wrote:

Sailun tires are as good as any GY tires made for RVs... personally I run a Geo Star Chinese made G rated 14 ply tire... starting 4th season... r7n them at 105 to 110 psi...

They will continue to perform quite well... GY G614 is a nice tire but not worth the cost factor when a good G rated 14 ply tire will work just as well

If you’ve got money to burn then buy the best....Sailun would be your huckleberry
So far there's no indication that the Sailun isn't the best. There are still a few reports of issues with the Goodyear and they have had some real problems in the past. So far I've read of 2 Sailun tires that there have been problems. If someone offered me my choice of tire at no cost to me, it would still be the Sailun with no hesitation.

IMO this is one of those times when higher price is not an indication of higher quality.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Prev  |  Next

Open Roads Forum  >  Fifth-Wheels

 > Tire pressure
Search:   Advanced Search

Search only in Fifth-Wheels


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

Adjust text size:

© 2019 CWI, Inc. © 2019 Good Sam Enterprises, LLC. All Rights Reserved. | Terms of Use | PRIVACY POLICY | YOUR PRIVACY RIGHTS