Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-30-2013, 06:40 AM   #127
CapriRacer
 
CapriRacer's Avatar
 
I'm in the , US
Join Date: Sep 2012
Posts: 624
Quote:
Originally Posted by dkottum View Post
Okay, many of us have upgraded to 16" Michelin LT tires from the original 15" GYM ST tires for reliability, and perhaps extra load capacity.

The question is, do we follow Airstream's recommendation for this tire upgrade (which is factory standard on some models and available as an option on others) of 80 psi (cold) or not? That is the maximum pressure printed on the sidewall.
Short answer: Use the maximum on the sidewall

Long answer: The way you have posed the question makes it unanswerable. What you are trying to achieve is a maximum of an 85% tire load (based on the load tables) and without knowing the actual loads on the tires you would be making a bunch of assumptions that may be unwarranted.

If you follow Airstreams recommended pressure (which also is the maximum on the sidewall) you are assuming that they have properly sized the tire - and we don't know that. It seems like a good assumption, since this is nominally an upgrade, but there may be situations where it isn't.
__________________

__________________
CapriRacer is offline   Reply With Quote
Old 10-30-2013, 05:35 PM   #128
Rivet Master
 
Moflash's Avatar
 
2007 28' International CCD
Springfield , Missouri
Join Date: Apr 2011
Posts: 1,167
It is hard to believe that some would spend the money for a Airstream trailer and be to frugal (cheap ) to buy a matching proper spare tire or forgo a spare tire at all .Wow I have seen it all
__________________

__________________
Moflash is offline   Reply With Quote
Old 10-30-2013, 06:29 PM   #129
4 Rivet Member
 
1966 24' Tradewind
2005 22' Safari
Bastrop , Texas
Join Date: Aug 2012
Posts: 329
Rivet

Quote:
Originally Posted by Moflash View Post
It is hard to believe that some would spend the money for a Airstream trailer and be to frugal (cheap ) to buy a matching proper spare tire or forgo a spare tire at all .Wow I have seen it all
As chief tightwad and bottle washer , I resemble that remark !

as Ben Franklin one time opined "A penny saved is a penny earned "
__________________
dannydimitt is offline   Reply With Quote
Old 10-30-2013, 06:34 PM   #130
Rivet Master
 
dkottum's Avatar
 
2012 25' Flying Cloud
Battle Lake , Minnesota
Join Date: Jun 2009
Posts: 7,716
Moflash, many of us have decided the standard 15" is "proper" enough to supplement the highly reliable 16" Michelins. Why is it unproper? A good answer and I'll go buy one.

As for no spare, that's also a choice for local travel on a tandem axle Airstream I suppose. I don't do it, but I wouldn't condemn someone who does.
__________________
Doug and Cheryl
2012 FC RB, Michelin 16, ProPride 1400
2016 Ram 1500 Laramie Crew Cab 4X4 Ecodiesel 3.92 axles

The Truth is More Important Than the Facts
dkottum is offline   Reply With Quote
Old 10-30-2013, 08:04 PM   #131
retired USA/USAF

 
2001 30' Excella
Somerset , New Jersey
Join Date: Jan 2009
Posts: 2,157
Now I know why I carry 2 spares. To loan one out of course !!!!!!
__________________
Roger in NJ

" Democracy is the worst form of government. Except for all the rest"
Winston Churchill 1948

TAC - NJ 18

polarlyse is offline   Reply With Quote
Old 10-30-2013, 08:08 PM   #132
Rivet Master
 
Ridgerunner3's Avatar
 
2002 25' Safari
Fountain Inn , South Carolina
Join Date: Sep 2011
Posts: 659
Images: 11
Quote:
Originally Posted by Moflash View Post
It is hard to believe that some would spend the money for a Airstream trailer and be to frugal (cheap ) to buy a matching proper spare tire or forgo a spare tire at all .Wow I have seen it all
A person could carry out that same logic to many hardware upgrades for your Airstream. Each person draws a line somewhere and says I am not going to spend money on that upgrade. For me I spent money on a Propride hitch but would not spend the money on the 16" wheel upgrade. I decided that I would limit my tire / wheel budget to the 15 Michelin tires & not go the whole way with the 16" wheels. Every person has a different set of budget criteria and risk analysis. Just my 2 cents.
__________________
Bud
Ridgerunner3 is offline   Reply With Quote
Old 10-30-2013, 08:35 PM   #133
Moderator
 
jcanavera's Avatar

 
2004 30' Classic Slideout
Fenton , Missouri
Join Date: Mar 2002
Posts: 9,002
Images: 143
Send a message via AIM to jcanavera Send a message via Skype™ to jcanavera
I bought a spare 16" wheel that is identical to the Airstream supplied 15" spare. I'm watching for a sale on LT tires locally. Since this new LT tire probably never see the ground much if any, I'm not going to spend as much for something that I consider a throw away after several years of sitting under the trailer.

Thinking about it I really pushed the envelope on my 15" spare. It's the original and has been on the ground once...but only to hold the weight of the trailer as it sat in the drive as I was doing tire swaps when replacing the original ST's.

Jack
__________________
Jack Canavera
STL Mo.
AIR #56
'04 Classic 30' S.O.,'03 GMC Savana 2500,'14 Honda CTX 700
jcanavera is offline   Reply With Quote
Old 10-30-2013, 10:55 PM   #134
Rivet Master
 
rodsterinfl's Avatar

 
2006 25' Safari
Fort Myers , Florida
Join Date: Oct 2011
Posts: 2,429
Images: 8
Quote:
The question is, do we follow Airstream's recommendation for this tire upgrade (which is factory standard on some models and available as an option on others) of 80 psi (cold) or not? That is the maximum pressure printed on the sidewall.
I was unable to find any information on truck tires and load; however, I did find several informational articles on trailer tires- how that it is critical that ST tires be run at maximum pressure due to thicker sidewall heat generation. That is not the case with LTX tires.

My posting of the LTX tire chart was not to create an issue but I thought it would be helpful consideration. I am still trying to find information about truck tires and loading. I know that on my truck I had to take some pressure off so I went to 60psi on the front, which was what the installer originally inflated them to. In the case of my truck, the placard says D rated 50psi and the sidewall says 80psi. The local Ford service manager said to inflate EITHER D or E rated tires at 50 psi on my vehicle regardless of sidewall rating- just sayin. I spoke to him Friday. As for my trailer LTX tires, I am still researching this.

I believe that there is merit in the chart. Michelin has an RV chart for the Rib tire. Looking at that tire chart, the load information is similar to the MS/2 in matching load to inflation. Why would the charts be published if everyone were to use maximum pressure when using the tire- for safety or other issues?

Here is an informational post from a truck forum poster I found, an 18 year tire company veteran, who interrupted their forum's very long thread on the same issue only related to trucks and carrying loads:

Quote:
"I worked for Michelin Tire Corporation for 7 years and Yokohama Tire Corporation for 11 years. I have given numerous tire seminars on tire maintenance and especially how to determine the correct tire pressures. So here goes.
The pressure on the sidewall of the tire is the maximum pressure at the published load at approximately 55 mph. (The speed can vary somewhat but it is not important for our discussion). The air pressure is required to support the load that the tire must carry in such a manner that the tire flexes at the designed place on the sidewall of the tire. If the load on the tire changes then the air pressure should change accordingly to keep the tire flexing at the proper place. The reason for correct air pressure is to prevent the tire from overheating. It was put together with heat and it will come apart the same way. An under inflated tire will eventually self destruct due to excessive heat build up. An over inflated tire will ride harshly and be more likely to burst upon impact. Sorry for the long explanation but here is the bottom line. To determine the correct air pressure, check the pressure when the tire is cold. Run the tire for several miles at highway speed. Stop and immediately check the air pressure in the tire. It should be higher than when cold but no more than 10% higher. Now here is the hard to believe part. If the pressure is more than 10% higher you must ADD AIR and test again. For example if you start with 50 psi cold. If the pressure is 60 when hot, you have exceeded the (10%) in this case, 55 psi maximum safe heat build up pressure. You must ADD AIR. In this case I would add 5 psi which would take the tire to 65 psi when hot. After you run the tire again you will find the pressure to actually drop because the tire will run cooler. The heat build up causes the tire pressure to increase when under inflated.
On the other hand, if the 50 psi cold pressure does not change when hot. You have more air than needed. You can remove 5 psi or so and test again when they return to cold. Like the next trip you take. So a fully loaded rig will require more air in the tires than one with empty tanks and a light load on board. Always error on the side of over inflation. Thus the maximum sidewall pressure indicated on the tire is usually used. It usually is more than needed. Each axle has its own requirement based upon the load on that axle."
LandcruiserPhil

I posted his words here because it, to me, answered many questions and clarified some responses. The main point is that we all are switching to 16" LTX tires for reliability and safety over that of the ST tires available. That will happen. As I stated earlier my only purpose was to post information from my quest on finding the optimum pressure since I was dealing with it on the tow vehicle too. For the record, I have learned more about tire pressure than I thought possible for a lay camper! No worries.
__________________
WBCCI 8653/AIR 60240
2017 Ford F-150 3.5 Ecobeast Gen 2 3.55 Platinum
rodsterinfl is offline   Reply With Quote
Old 10-31-2013, 12:05 AM   #135
Rivet Master
 
dkottum's Avatar
 
2012 25' Flying Cloud
Battle Lake , Minnesota
Join Date: Jun 2009
Posts: 7,716
Boy it's hard to get a straight answer on the correct tire pressure for the Michelin 16" XL upgrade (or standard on EB models) for Airstream.

Airstream has 80 psi on their trailer placard for those models where the tire is standard, their Service Center at the factory recommends 80 psi (I was there last week and asked them directly, the Service Manager and the tech airing my tires); here it's yes, no, maybe, but, and if. Or I know someone who . . .

I'll stay with the 80 psi.
__________________
Doug and Cheryl
2012 FC RB, Michelin 16, ProPride 1400
2016 Ram 1500 Laramie Crew Cab 4X4 Ecodiesel 3.92 axles

The Truth is More Important Than the Facts
dkottum is offline   Reply With Quote
Old 10-31-2013, 12:23 AM   #136
Rivet Master
 
Howard L.'s Avatar
 
2012 30' Flying Cloud
San Antonio , Texas
Join Date: Jul 2012
Posts: 591
((((To determine the correct air pressure, check the pressure when the tire is cold. Run the tire for several miles at highway speed. Stop and immediately check the air pressure in the tire. It should be higher than when cold but no more than 10% higher. Now here is the hard to believe part. If the pressure is more than 10% higher you must ADD AIR and test again. For example if you start with 50 psi cold. If the pressure is 60 when hot, you have exceeded the (10%) in this case, 55 psi maximum safe heat build up pressure. You must ADD AIR. In this case I would add 5 psi which would take the tire to 65 psi when hot. After you run the tire again you will find the pressure to actually drop because the tire will run cooler. ))))

There is much great info on this thread. After reading it the first time, I became convinced I should, and actually did, take the GYMs off our new 30 flying cloud and install load E tires. 15 inch trailer tires, not 16" LTs but 10 ply, 80 # tires just the same. But there are also some posts that are confusing and misleading. I believe the above statement was made from a base of knowledge. And, in general terms may well be correct--in a way, makes perfect sense (higher pressure = cooler running.). However, I know from my own test it will not always be that simple. My test: 80 psi on new Maxxis when cold. Stop and test pressure 2 hours later while pulling trailer at 65 mph on Texas interstate 10 with outside air temp 102. Tire pressure 90 psi. That breaks the 10% rule and would require cold inflation above the cold max if above instructions were followed.

For a softer ride, or better braking (if you believe less pressure achieves that), stick with the GYMs or any other D tire and fill them to 65 psi (check your weights, maybe you can drop down to a C rated tire). If you want a tire Built to perform well with weights way in excess of of our Airstreams, and you want that overkill for safety reasons, put the Es on and air them up to E @ 80psi. If you just have to do something different, then drop to 75. Don't get tied up with what the auto manufactures do, as explained earlier, they will lower the psi door sticker so that the max chart weight the tires will carry will match the trucks axle and not exceed it. We should not care about that. We're not going to exceed the axle weight (well except some of the older 3500# axles) or the 10 ply tire weight. We just want the largest safety margin available and the more we lower the tire pressure the less of that we have and the more the tire heats up. Rocket Science 101.
__________________
Howard L. is offline   Reply With Quote
Old 10-31-2013, 02:31 PM   #137
Moderator
 
jcanavera's Avatar

 
2004 30' Classic Slideout
Fenton , Missouri
Join Date: Mar 2002
Posts: 9,002
Images: 143
Send a message via AIM to jcanavera Send a message via Skype™ to jcanavera
One of the things that doesn't get too much mention is speed. One of the things I was taught is that the faster you go, the more heat you build up due to the flexing of the tire. The faster the rotation, the more flexing that occurs. Some tires dissipate heat faster than others or have compounds that can handle higher temperatures. Supposedly that is one reason why if you exceed the speed rating of a tire, the more likely you are in danger of failure due to heat build up.

Jack
__________________
Jack Canavera
STL Mo.
AIR #56
'04 Classic 30' S.O.,'03 GMC Savana 2500,'14 Honda CTX 700
jcanavera is offline   Reply With Quote
Old 10-31-2013, 04:14 PM   #138
Rivet Master
 
Moflash's Avatar
 
2007 28' International CCD
Springfield , Missouri
Join Date: Apr 2011
Posts: 1,167
I have put 8000 miles or more on 16 LT's I run 70lbs.I have checked the internal temps real time at 80psi and at 70psi the difference at hwy speeds at various outside temps up to 103f is negligible.For me 70psi is the number.
My background 39 years in the automobile business so I have see a few tires fail and survive.

I also have a matching size spare tire on all my vehicles including my Airstream
for three reasons

A.The 15 inch ST tire is 1.1 inch smaller in diameter than the 16 LT

B.Why would I keep a tire for a spare that has a high failure rate? Not

C.Just knowing that I did something half a**ed would drive me crazy as my life revolves around Murphy's Law.

I also believe tires die in five years and must be replaced even if they look new on the outside they are dry rotted inside.I have seen it over and over again.
__________________
Moflash is offline   Reply With Quote
Old 11-07-2013, 10:20 PM   #139
Rivet Master
 
rodsterinfl's Avatar

 
2006 25' Safari
Fort Myers , Florida
Join Date: Oct 2011
Posts: 2,429
Images: 8
Quote:
However, I know from my own test it will not always be that simple. My test: 80 psi on new Maxxis when cold. Stop and test pressure 2 hours later while pulling trailer at 65 mph on Texas interstate 10 with outside air temp 102. Tire pressure 90 psi. That breaks the 10% rule and would require cold inflation above the cold max if above instructions were followed. For a softer ride, or better braking (if you believe less pressure achieves that), stick with the GYMs or any other D tire and fill them to 65 psi (check your weights, maybe you can drop down to a C rated tire).
Hey Howard, what Phil shared about testing tire pressure and also sidewall arching at a certain point related to the weight is, in my opinion a great description of dialing in the perfect pressure for the load being carried. That does not mean you can use any load range tire for lower pressure. What makes it even better is how a TPMS can make this easy- one that reads PSI and temp. I totally understand DKottum and others' concerns for doing what is best. I do not run any tires at maximum pressure personally; however, I now understand why ST tires are to be maxed out. I plan to try what Phil prescribed using my TPMS with my CAT scale readings with a 20% leeway to start.
__________________
WBCCI 8653/AIR 60240
2017 Ford F-150 3.5 Ecobeast Gen 2 3.55 Platinum
rodsterinfl is offline   Reply With Quote
Old 11-12-2013, 09:25 AM   #140
Rivet Master
 
rodsterinfl's Avatar

 
2006 25' Safari
Fort Myers , Florida
Join Date: Oct 2011
Posts: 2,429
Images: 8
Hello 16" wheel peeps. As I previously mentioned I got the sendel wheels. Today I ordered the ms/2 tires but in discussing the install with the manager at SAMs he said they could not mount them on the wheel with warranty if it was going on a trailer. I told him the factory was using them now on their 16" wheel option but he said without an official statement he could not mount them on the wheels. He said to go ahead with the order and in the meantime he would check on it. The tires went on sale today. Any ideas? I looked on the Internet for something from Airstream.
__________________

__________________
WBCCI 8653/AIR 60240
2017 Ford F-150 3.5 Ecobeast Gen 2 3.55 Platinum
rodsterinfl 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



Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:22 AM.


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.