Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 08-14-2013, 09:03 AM   #1
Member
 
Join Date: Jun 2013
Posts: 42
coach weight and tire pressure

Had my 05 Mandalay weighed at a truck scale and the readings were shown like this... Steering 12200
trailer 19200
-----------
31400 lbs.

I am thinking this is front and rear lbs.. Is this a reasonable method to use to inflate tires? Currently at 100psi for 2 front and 4 rear.
Thanks for any input RFS
__________________

__________________
R F S is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 08-14-2013, 09:16 AM   #2
Senior Member
 
Sky_Boss's Avatar


 
Newmar Owners Club
Spartan Chassis
Join Date: Apr 2012
Location: ON THE ROAD...SOMEWHERE
Posts: 6,068
It is a start but you really need corner weights to complete the picture.

Do you have any more info to share such as your axle weight ratings and tire maker/size?
__________________

__________________
Don, Sandee & GSD Zeus. Guardian GSDs Gunny (7/11/15) & Thor (5/5/15)
2006 DSDP 4320, Spartan MM IFS, 2013 CR-V, Blue Ox Avail, SMI AF1, Samsung 197R Refer.
Sky_Boss is offline   Reply With Quote
Old 08-14-2013, 11:54 AM   #3
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,073
Yes that is a reasonable place to start. Individual tire weights would be better, but what you have is adequate.

Divide the front (steer) axle weight by two to get individual tire weight and then add 300-400 lbs to allow for a possible imbalance (one side heavier than the other). Then look that up in the inflation table for your brand and size of tire to get the recommended psi value. Maybe go 5 lbs higher to give some extra safety margin.

For the rear (drive) axle, divide by 4 to find individual tire weights and add 300 lbs each for possible imbalanced load. Then look that weight up in the inflation tables. Again, an extra 5 psi will help assure you won't ever be low.
__________________
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 08-14-2013, 05:09 PM   #4
Senior Member
 
Ray,IN's Avatar
 
Join Date: Aug 2001
Location: North America somewhere
Posts: 13,699
Keep in mind all the weight/inflation charts say that is the minimum recommended pressure for the corresponding load. It is not necessarily the optimum pressure.
__________________
2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member,FMCA."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert the Constitution. "Abraham Lincoln"
Ray,IN is offline   Reply With Quote
Old 08-14-2013, 05:10 PM   #5
Senior Member
 
adonh's Avatar
 
Join Date: Apr 2013
Location: Missouri City, TX
Posts: 1,306
Quote:
Originally Posted by Gary RVRoamer View Post
Yes that is a reasonable place to start. Individual tire weights would be better, but what you have is adequate.

Divide the front (steer) axle weight by two to get individual tire weight and then add 300-400 lbs to allow for a possible imbalance (one side heavier than the other). Then look that up in the inflation table for your brand and size of tire to get the recommended psi value. Maybe go 5 lbs higher to give some extra safety margin.

For the rear (drive) axle, divide by 4 to find individual tire weights and add 300 lbs each for possible imbalanced load. Then look that weight up in the inflation tables. Again, an extra 5 psi will help assure you won't ever be low.
On the Michelin inflation guide for the tires on my coach they list tire pressure by weight as Single and Dual. I put together a chart based on the GVWR per chassis ID tag, the actual scale weight of the front and rear axle (unable to weigh the 4 corners), a mid range weight between GVWR and actual weight and finally the tire maximum pressure per Michelin. I then matched up as close as I could the PSI per the chart.

275-70R 22.5 tire inflation guide.pdf

Based on this what would be the recommended tire pressure, front and rear, thanks
__________________
Don
2003 Forest River Cardinal Platinum 37' 5th Wheel
1976 31' Airstream
adonh is offline   Reply With Quote
Old 08-14-2013, 06:01 PM   #6
Senior Member
 
FlyingDiver's Avatar
 
Newmar Owners Club
Join Date: May 2007
Location: Somewhere....
Posts: 3,820
Quote:
Originally Posted by Ray,IN View Post
Keep in mind all the weight/inflation charts say that is the minimum recommended pressure for the corresponding load. It is not necessarily the optimum pressure.
Never seen that verbiage on the Michelin charts. They say:

Quote:
For RV use only, Michelin displays tire loads per axle end in the load and inflation tables, as we recommend weighing each axle end separately and using the heaviest end weight to determine the axle's cold inflation tire pressure. For control of your RV,it is critical the tire pressures are the same across an axle, while NEVER exceeding the maximum air pressure limit stamped on the wheels.
Emphasis mine.
__________________
2008 King Aire 4562, Spartan K3(GT) w/ Cummins ISX 600
2014 Jeep Grand Cherokee Overland 5.7L V8 Hemi w/ Blue Ox Aventa LX Tow Bar and baseplate, SMI Air Force One brake
FlyingDiver is offline   Reply With Quote
Old 08-15-2013, 10:13 AM   #7
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,073
Quote:
On the Michelin inflation guide for the tires on my coach they list tire pressure by weight as Single and Dual. I put together a chart based on the GVWR per chassis ID tag, the actual scale weight of the front and rear axle (unable to weigh the 4 corners), a mid range weight between GVWR and actual weight and finally the tire maximum pressure per Michelin. I then matched up as close as I could the PSI per the chart.
Since you don't have a scaled weight for the coach when loaded for travel, you have to assume the axles may be fully loaded to their GAWR's. That means you would use the line you have labeled "GVWR".

You could gamble on the "midway" numbers, but they are only 5 psi different than the GVWR set, so there is really nothing to be gained by taking that chance.
__________________
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 08-15-2013, 10:26 AM   #8
Senior Member
 
2 Stroker's Avatar
 
Join Date: Nov 2009
Location: Warren, Oregon
Posts: 1,719
I just had my coach weighted at the FMCA Rally in Albany,Or (4 corner wt) and I'm over wt in the rear by 1150lbs and under in the front by 730lbs. In January I got a new set of Michelin 295/80R22.5 XZA2 with a max PSI of 120lbs.
With a combined wt of 33,620lbs
FR 6,405lbs-FL 6,065lbs RR 10,195lbs-LR 10,955lbs
I have to run 105 PSI in the front and 100 PSI in the rear by the numbers given. This is the only way to get a true wt reading and know what PSI to run, money well spent. Must be the new steel and copper radiator and not the way the wife packed the coach on the LR
2 stroker
__________________
2006 Country Coach Inspire 360 40ft Genoa Designer Series, Samsung 197 RR
Cat C9--STEEL & COPPER Bolt Together Radiator w/ updated rubber mounting
SilverLeaf 330 Magnum 2812 PSW 2011 Ford Edge Sport-Air Force One
2 Stroker is offline   Reply With Quote
Old 08-15-2013, 11:38 AM   #9
Senior Member
 
Sky_Boss's Avatar


 
Newmar Owners Club
Spartan Chassis
Join Date: Apr 2012
Location: ON THE ROAD...SOMEWHERE
Posts: 6,068
Quote:
Originally Posted by 2 Stroker View Post
I just had my coach weighted at the FMCA Rally in Albany,Or (4 corner wt) and I'm over wt in the rear by 1150lbs and under in the front by 730lbs. In January I got a new set of Michelin 295/80R22.5 XZA2 with a max PSI of 120lbs.
With a combined wt of 33,620lbs
FR 6,405lbs-FL 6,065lbs RR 10,195lbs-LR 10,955lbs
I have to run 105 PSI in the front and 100 PSI in the rear by the numbers given. This is the only way to get a true wt reading and know what PSI to run, money well spent. Must be the new steel and copper radiator and not the way the wife packed the coach on the LR
2 stroker
I'm Confused...

You were 1150# over on the rear?! That is a lot. There is no way that I know of to simply use more tire pressure to compensate for that. You still have to deal with the axle rating no matter whether or not your tires can handle the weight.

Maybe I missed something?
__________________
Don, Sandee & GSD Zeus. Guardian GSDs Gunny (7/11/15) & Thor (5/5/15)
2006 DSDP 4320, Spartan MM IFS, 2013 CR-V, Blue Ox Avail, SMI AF1, Samsung 197R Refer.
Sky_Boss is offline   Reply With Quote
Old 08-15-2013, 12:35 PM   #10
Senior Member
 
2 Stroker's Avatar
 
Join Date: Nov 2009
Location: Warren, Oregon
Posts: 1,719
Quote:
Originally Posted by Sky_Boss View Post
I'm Confused...

You were 1150# over on the rear?! That is a lot. There is no way that I know of to simply use more tire pressure to compensate for that. You still have to deal with the axle rating no matter whether or not your tires can handle the weight.

Maybe I missed something?
The numbers are with a full tank fuel and full water but I only run with 20-25 gallons of water because we stay at campgrounds all the time. He said if I could move some of the stuff to the front bay that would help but he said Country Coaches are just heavy. Overall I am 420lbs over but if I take off for about 80 gallons of water I should be 220lbs under. The numbers say 100psi rear and 105psi front. There is nothing I can do about it beside taking the bed out, I may just do that and go with a sleep number because the one in there must weigh a good 200lbs
2 stroker
__________________
2006 Country Coach Inspire 360 40ft Genoa Designer Series, Samsung 197 RR
Cat C9--STEEL & COPPER Bolt Together Radiator w/ updated rubber mounting
SilverLeaf 330 Magnum 2812 PSW 2011 Ford Edge Sport-Air Force One
2 Stroker is offline   Reply With Quote
Old 08-15-2013, 10:33 PM   #11
Senior Member
 
dons2346's Avatar
 
Country Coach Owners Club
Join Date: Dec 2010
Posts: 4,481
Rear axles on most coaches are rated at 23,000lbs. It is DOT that says each axle cannot be over 20,000.

1150 over on the rear isn't bad at all considering that the non tag Beaver and Safari with the big Cat motor was overweight out of the factory before you put your toothbrush in it. There was a model of the Travel Supreme that was in the same situation. I know of a TS single axle that was taken back to the factory where they cut it apart and installed a tag.

Floyd, what does your data plate say? Most CC's say 120 front and 110 rear.

Also might help if you unload some of that ammo you carry and don't blame the extra weight on the wife!
__________________
dons2346 is offline   Reply With Quote
Old 08-15-2013, 11:06 PM   #12
Senior Member
 
2 Stroker's Avatar
 
Join Date: Nov 2009
Location: Warren, Oregon
Posts: 1,719
Quote:
Originally Posted by dons2346 View Post
Rear axles on most coaches are rated at 23,000lbs. It is DOT that says each axle cannot be over 20,000.

1150 over on the rear isn't bad at all considering that the non tag Beaver and Safari with the big Cat motor was overweight out of the factory before you put your toothbrush in it. There was a model of the Travel Supreme that was in the same situation. I know of a TS single axle that was taken back to the factory where they cut it apart and installed a tag.

Floyd, what does your data plate say? Most CC's say 120 front and 110 rear.

Also might help if you unload some of that ammo you carry and don't blame the extra weight on the wife!
Don
The front reads 105psi
rear 95psi
She said, what jn the world can you put in these things. We have boxes in the garage that came out of the Alpenlite 5er. I did unload the ammo but she wants it back in so my toothbrush will stay home.
2 stroker
__________________
2006 Country Coach Inspire 360 40ft Genoa Designer Series, Samsung 197 RR
Cat C9--STEEL & COPPER Bolt Together Radiator w/ updated rubber mounting
SilverLeaf 330 Magnum 2812 PSW 2011 Ford Edge Sport-Air Force One
2 Stroker is offline   Reply With Quote
Old 08-15-2013, 11:31 PM   #13
Senior Member
 
Mr_D's Avatar
 
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 28,452
Quote:
Originally Posted by dons2346 View Post
Rear axles on most coaches are rated at 23,000lbs. It is DOT that says each axle cannot be over 20,000.
Nope, the DOT added an exemption for RV's now and they are allowed to use 23,000# axles. This was over a year ago. And very few MH's had 23,000# axles before this. The old Monaco tried this and ended up having to buy back some single axle units and replace them with tag axle units.
__________________
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '14 CR-V
Mr_D is offline   Reply With Quote
Old 08-15-2013, 11:36 PM   #14
Senior Member
 
Mr_D's Avatar
 
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 28,452
Quote:
Originally Posted by 2 Stroker View Post
In January I got a new set of Michelin 295/80R22.5 XZA2 with a max PSI of 120lbs.
On Michelin tires and some others the pressure on the tire sidewall is the minimum to support the maximum rating of the tire. This is spelled out in their literature.
Quote:
From page 2 of the 06/07 Michelin RV Tire Guide: "If you look at the tire's sidewall, you'll see the maximum load capacity allowed for the size tire and load rating, and the minimum cold air inflation needed to carry the maximum load."
__________________

__________________
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '14 CR-V
Mr_D is offline   Reply With Quote
Reply

Tags
tire pressure, weight



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 09:31 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.