Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-11-2014, 07:22 AM   #57
CapriRacer
 
CapriRacer's Avatar
 
I'm in the , US
Join Date: Sep 2012
Posts: 624
Quote:
Originally Posted by MrJim View Post
FWIW, I was reading the original manual for our '71 Safari, and finally noticed that Airstream officially recommended 60 PSI for our tires in it. That's also what was recommended to us by CGTrailers (cgtrailer.com) when we asked them about it after having some work done there.

After pulling the trailer through over a dozen miles of some horridly bumpy dirt roads in Mexico recently, we realized there's also a case for lowering air pressure on such "roads", to avoid destroying everything inside the trailer (a front side window, in this case), so dropped it to 55PSI on the return trip with no further damage.

We also had CG Trailers add a spare tire, just in case. It cleverly mounts under the front of the trailer.
Jim,

I hope your realize that lowering the pressure also lowered the load carrying capacity of the tire - and in turn, that increases the risk of a tire failure - and I hope I don't have to tell you about tire failures on trailers.

Also, there has been a lot of changes since 1971. While tires have gotten better, more scrutiny has been place on the inflation pressure recommendations made by vehicle manufacturers. I would be very hesitant to state that what they recommended in 1971 is applicable today. To be sure, you need to weigh the trailer.
__________________

__________________
CapriRacer is offline   Reply With Quote
Old 01-11-2014, 07:54 AM   #58
Top
Always learning
 
Top's Avatar
 
1972 29' Ambassador
1962 19' Globetrotter
1951 21' Flying Cloud
Central , Texas
Join Date: Oct 2010
Posts: 2,779
Images: 24
Blog Entries: 2
Send a message via Yahoo to Top
Quote:
Originally Posted by MrJim View Post
FWIW, I was reading the original manual for our '71 Safari, and finally noticed that Airstream officially recommended 60 PSI for our tires in it. That's also what was recommended to us by CGTrailers (cgtrailer.com) when we asked them about it after having some work done there.

After pulling the trailer through over a dozen miles of some horridly bumpy dirt roads in Mexico recently, we realized there's also a case for lowering air pressure on such "roads", to avoid destroying everything inside the trailer (a front side window, in this case), so dropped it to 55PSI on the return trip with no further damage.

We also had CG Trailers add a spare tire, just in case. It cleverly mounts under the front of the trailer.
Are you running 7.00x15 LT bias ply tires like it came from the factory in '71?

If so, then what the owner's manual states might be OK. It would still be best to match inflation pressure with actual tire load from an accurate scale.
__________________

__________________
Lance

Work is never done, so take time to play!
Top is offline   Reply With Quote
Old 01-11-2014, 10:19 AM   #59
Top
Always learning
 
Top's Avatar
 
1972 29' Ambassador
1962 19' Globetrotter
1951 21' Flying Cloud
Central , Texas
Join Date: Oct 2010
Posts: 2,779
Images: 24
Blog Entries: 2
Send a message via Yahoo to Top
From my '72 owner's manual.
Click image for larger version

Name:	IMG_0288.jpg
Views:	89
Size:	268.0 KB
ID:	203354
Click image for larger version

Name:	IMG_0289.jpg
Views:	78
Size:	200.8 KB
ID:	203355
__________________
Lance

Work is never done, so take time to play!
Top is offline   Reply With Quote
Old 01-12-2014, 12:28 PM   #60
Rivet Master
Commercial Member
 
Ravenna , Ohio
Join Date: Apr 2012
Posts: 690
I trust that if you are somehow finding bias 7.00x15 "8 ply" you are making sure they are 5 years old or less.
__________________
Retired tire engineer (40 years). Write a blog on RV tires.
Tireman9 is offline   Reply With Quote
Old 01-12-2014, 02:49 PM   #61
Rivet Master
 
rideair's Avatar
 
Join Date: Sep 2004
Posts: 1,223
Wow, I had no idea so much time and effort could be spent on tire pressue for something you are dragging around behind a truck. I have 5 Airstreams, all running 7.00x15 bias ply tires that always have the max pressure allowed (normally 60psi and they don't heat up). Finally after 12 years I had one of them (which was 11 years old) let go of about 2/3rds of the tread (but the tire did not blow out) going to Florida last year.

There's a reason why 18 wheelers normally keep their tires at max pressure. If they spent the amount of time it would take changing the tire pressure for each load, you would never get your fresh veggies from the store!

Some might say, "You will beat your trailer to death", if you're beating your trailer to death, I first would start looking at how old the axles are and then worry about the tires (get them balanced, with high pressure valve steams and if you're really worried get a set of Centramatics) and you should be fine running any tire at max pressure.

Oh well, I'll stick with the old bias plys 7.00x15's (you can still find them new, I have 12 of them waiting to be installed) at 60psi. Great thing about the old bias plys, if one blows out, I don't have a chainsaw going down the side of my trailer ;-)

Enjoy,
__________________
Paul Waddell
rideair is offline   Reply With Quote
Old 01-12-2014, 03:36 PM   #62
CLOUDSPLITTER "Tahawas"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , WNY
Join Date: Jun 2007
Posts: 11,153
Images: 1
Thumbs up

Well said Paul....

Bob
__________________
PFC.....

“After all these years the reason I continue to love Thanksgiving.....I still sit at the kids table.”
RLC

Sandra wanted to go to Cleveland on vacation,
but I’m the Husband, so we went to Cleveland.
RLC
ROBERT CROSS is offline   Reply With Quote
Old 01-24-2014, 11:20 AM   #63
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
Here's some info from RVSEF on weighing your trailer. You should also investigate their site. They have a calendar (which will be updated as the year goes on) where their teams are scheduled for weighing services. You might find an event or location close to you. I have used them once when they were in the St. Louis area and was very pleased by the results and services they gave.

Frequently Asked Questions About RV Weighing

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 01-24-2014, 11:24 PM   #64
2 Rivet Member
 
1971 23' Safari
Arlington Hts , Illinois
Join Date: May 2013
Posts: 51
Looks like RVSEF won't be near my trailer this year. (It's currently in Irvine, CA.) But thanks for suggesting them.

The main weight that I'd like to measure is hitch weight. I just bought a bath scale that claims to handle up to 400 pounds. Has anyone tried using such a scale to measure the hitch weight on an Airstream with an expected hitch weight within that range?
__________________
MrJim is offline   Reply With Quote
Old 01-25-2014, 10:26 AM   #65
Rivet Master
 
1988 32' Excella
Robbinsville , New Jersey
Join Date: May 2012
Posts: 1,010
Quote:
Originally Posted by MrJim View Post
Looks like RVSEF won't be near my trailer this year. (It's currently in Irvine, CA.) But thanks for suggesting them.

The main weight that I'd like to measure is hitch weight. I just bought a bath scale that claims to handle up to 400 pounds. Has anyone tried using such a scale to measure the hitch weight on an Airstream with an expected hitch weight within that range?
This thread ha instructions on how to weight heavier trailer tongues then that range.

http://www.airforums.com/forums/f464...ale-24195.html
__________________
Wazbro is offline   Reply With Quote
Old 01-26-2014, 12:26 PM   #66
Rivet Master
Commercial Member
 
Ravenna , Ohio
Join Date: Apr 2012
Posts: 690
Quote:
Originally Posted by MrJim View Post
Looks like RVSEF won't be near my trailer this year. (It's currently in Irvine, CA.) But thanks for suggesting them.

The main weight that I'd like to measure is hitch weight. I just bought a bath scale that claims to handle up to 400 pounds. Has anyone tried using such a scale to measure the hitch weight on an Airstream with an expected hitch weight within that range?

Do you have a CAT scale or similar near you?. Simply get F & R axle weight with the RV attached. Then pull into parking area, drop the trailer and get another F& R.

You might discover you are not just adding hitch weight but transfering some load from front axle to rear also.
__________________
Retired tire engineer (40 years). Write a blog on RV tires.
Tireman9 is offline   Reply With Quote
Old 04-01-2014, 07:10 PM   #67
4 Rivet Member
 
2006 30' Classic
Milton , Florida
Join Date: Nov 2008
Posts: 256
Individual Tire Loads

Quote:
Originally Posted by Tireman9 View Post
...Do you have a CAT scale or similar near you?. Simply get F & R axle weight with the RV attached...
A while back, we weighed our travel trailer on the CAT scales and got a total weight of 7,300 pounds, rigged for towing. Rigged for towing means with a full water tank, all of the misc. junk that we normally carry and weight distribution bars tensioned, but no clothing or food on board. On average, this translates to 1,825 pounds per tire.


Today, we were able to obtain individual wheel weights using portable scales. The results are (rigged for towing)


Left Front - 2,000 pounds Left Rear - 1,900 pounds


Right Front - 1,900 pounds Right Rear - 1,700 pounds


Perhaps one of the tire guys may wish to comment on these numbers.
__________________
F. A. Meloy
2006 30' Classic
Dexter hydraulic disc brake system
Centramatics wheel balancing & Dill TPMS
Hensley hitch & Maxim skylights
Voyager Camera System WVOS713
2010 FORD F-250, ITBC, 6.8 liter V-10 gas, with VIAIR on-board air system
nickmeloy is offline   Reply With Quote
Old 04-01-2014, 10:47 PM   #68
3 Rivet Member
 
BlackAces's Avatar
 
Taylors , South Carolina
Join Date: Nov 2012
Posts: 119
Quote:
Originally Posted by nickmeloy View Post
A while back, we weighed our travel trailer on the CAT scales and got a total weight of 7,300 pounds, rigged for towing. Rigged for towing means with a full water tank, all of the misc. junk that we normally carry and weight distribution bars tensioned, but no clothing or food on board. On average, this translates to 1,825 pounds per tire.


Today, we were able to obtain individual wheel weights using portable scales. The results are (rigged for towing)


Left Front - 2,000 pounds Left Rear - 1,900 pounds


Right Front - 1,900 pounds Right Rear - 1,700 pounds


Perhaps one of the tire guys may wish to comment on these numbers.
I think you should balance your load.

BA
__________________
BlackAces
USN - RET - PDRL
DoD & SSA - RET
BlackAces is offline   Reply With Quote
Old 04-01-2014, 11:04 PM   #69
Rivet Master
 
dkottum's Avatar
 
2012 25' Flying Cloud
Battle Lake , Minnesota
Join Date: Jun 2009
Posts: 7,716
Quote:
Originally Posted by BlackAces View Post
I think you should balance your load.

BA
Seriously?
__________________
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 04-02-2014, 06:57 AM   #70
CapriRacer
 
CapriRacer's Avatar
 
I'm in the , US
Join Date: Sep 2012
Posts: 624
Quote:
Originally Posted by nickmeloy View Post
A while back, we weighed our travel trailer on the CAT scales and got a total weight of 7,300 pounds, rigged for towing. Rigged for towing means with a full water tank, all of the misc. junk that we normally carry and weight distribution bars tensioned, but no clothing or food on board. On average, this translates to 1,825 pounds per tire.


Today, we were able to obtain individual wheel weights using portable scales. The results are (rigged for towing)


Left Front - 2,000 pounds Left Rear - 1,900 pounds


Right Front - 1,900 pounds Right Rear - 1,700 pounds


Perhaps one of the tire guys may wish to comment on these numbers.

First, be aware that you didn't weigh the trailer in the worst case condition. At the very least, you missed the clothes and the food - and while that may seem trivial, those things add weight and we need to compensate for their absence.

Second, there is a discrepancy between the weights you posted. The average of those 4 reading is 1875 #, not 1825# you previously quoted.

Also, the round numbers leads me to believe that the weights are rounded to the nearest 100#. I think it is important to be aware of that.

So doing the math, the worst wheel position is the Left Front. That is about 7% above the average and 10% about the 1825# reading you quoted. Obviously there is a side to side variation that would be helped by moving stuff around.

I think it is a good idea to have tires operate at 85% of their rated capacity - so that means you need tires rated at 2353#.

I'm trying to find what tires you have on your trailer, but I went back 6 months....... So what are they? I would want to adjust ST tires so you could operate at 85 mph - as opposed to the normal 65 mph - but I don't know if you have ST tires.
__________________

__________________
CapriRacer 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 02:13 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.