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 06-18-2014, 06:21 AM   #29
Senior Member
 
mytime's Avatar
 
Join Date: May 2009
Location: Usually along the East Coast
Posts: 278
What JFNM said, you are not driving an over the road truck, but I see the tractor most cases has tires and wheels as nice as a high end MH, I expect the take good care of those, the trailer may be a little different.. Not the same as a MH..it too has that Peace of Mind factor also..I will still adjust my psi to weight factor.. Knowing is satisfaction
__________________

__________________
mytime 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 06-18-2014, 09:33 AM   #30
Senior Member
 
Gordon Dewald's Avatar
 
Winnebago Owners Club
Join Date: Mar 2014
Posts: 10,152
Quote:
Originally Posted by JEEPOHOLIC View Post
why weigh all 4 corners, if your only going to air up both front tires the same no mater if 1 side is heaver than the other in the front ?
Primarily the 4 corner weight is for coaches with air suspension. It can also show to a disproportionate side to side loading in the coach. RV with springs may be adjustable but I think it would take a top notch spring shop to work out the finer points.

The air suspension is dependent upon ride height. Most air suspensions can be adjusted. A small height difference can result in quite large differences in the 4 corner weights.

Same for tag axles. If the suspension on the tag is too high it can lift weight off of the drivers and some of that weight goes to the front.

In a perfect world the weight would be equal or very close to equal side to side. Theoretically if the coach were balanced perfectly side to side and then you and the DW sat in the front seats the front corners would show the difference (close) in weight between the two of you.

Loading is a fine art in the OTR world. Placement of the load affects axle loading and they will play with the loads arrangement so all axles are legal. A friend was the manager of a sawmill that had its own scales. They would always load the trucks to the maximum. In their case the side to side loading was taken care of by placing the loads symmetrically side to side. The last 'lift' would be placed on the center of the lumber below.

I am going to be more careful of how I deal with loading and tire pressures in the future. Thanks to various threads and the posters I have learned a lot about the intricacies of tire management. I have access to a scale that I can get corner weights so I will be playing with loading arrangements and suspension in order to get as close to even as possible. I hope to get within a couple hundred lbs side to side on each axle. Probably not realistic but I am going to try.

May have to stack the beer opposite the fridge instead of inside it!!! LOL
__________________

__________________
Gordon and Janet
Tour 42QD/inTech Stacker
Gordon Dewald is online now   Reply With Quote
Old 06-18-2014, 10:12 AM   #31
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,715
Quote:
Originally Posted by Gordon Dewald View Post
Primarily the 4 corner weight is for coaches with air suspension. It can also show to a disproportionate side to side loading in the coach. RV with springs may be adjustable but I think it would take a top notch spring shop to work out the finer points.

The air suspension is dependent upon ride height. Most air suspensions can be adjusted. A small height difference can result in quite large differences in the 4 corner weights.

Same for tag axles. If the suspension on the tag is too high it can lift weight off of the drivers and some of that weight goes to the front.

In a perfect world the weight would be equal or very close to equal side to side. Theoretically if the coach were balanced perfectly side to side and then you and the DW sat in the front seats the front corners would show the difference (close) in weight between the two of you.

Loading is a fine art in the OTR world. Placement of the load affects axle loading and they will play with the loads arrangement so all axles are legal. A friend was the manager of a sawmill that had its own scales. They would always load the trucks to the maximum. In their case the side to side loading was taken care of by placing the loads symmetrically side to side. The last 'lift' would be placed on the center of the lumber below.

I am going to be more careful of how I deal with loading and tire pressures in the future. Thanks to various threads and the posters I have learned a lot about the intricacies of tire management. I have access to a scale that I can get corner weights so I will be playing with loading arrangements and suspension in order to get as close to even as possible. I hope to get within a couple hundred lbs side to side on each axle. Probably not realistic but I am going to try.

May have to stack the beer opposite the fridge instead of inside it!!! LOL
You are on the right path to getting your coach as well balanced as possible. I am amazed at how many tag axle MH's on the road that are carrying close to the same weight on the two steer tires as the four drive tires. When I took delivery of our 43' tag coach, the steer was at 15,300, drive 14,900 and the tag was 9500#s. Also, the front right was 950# heavier than the left. When I was done, the steer is 14,600, drive is 19,600 and the tag is 5500#. And, the front tire weights are within 150# of each other. It took some time and the help of the State Patrol coming to my home with their six scales to confirm my results.

You would be surprised how many coaches are just as unbalanced as mine was and don't know it. It seems that the manufacturers pay more attention to not exceeding tire and axle ratings and not enough time getting to a better distribution of weight. With a tag coach it is all determined by ride height and tag air bag pressure. It's not that complicated. Good Luck
__________________
Crasher is online now   Reply With Quote
Old 06-18-2014, 10:28 AM   #32
Senior Member
 
Join Date: Feb 2010
Posts: 569
When I was an OTR driver our company kept all tires at 90 psi. We never adjusted our tire pressure, no matter what weight we were carrying.
__________________
2008 Thor, Four Winds Mandalay 40G. Cummins 400 isl. Freightliner chassis
koda59 is offline   Reply With Quote
Old 06-18-2014, 10:50 AM   #33
Member
 
Join Date: Aug 2012
Posts: 50
Another view

As a car nut and former club racer, tire pressure is EXTREMELY important. While a Class A is very different than a 3000 pound race car, the extreme loading of the race tire has lessons for all tired vehicles.

A good race driver can easily distinguish a 1/2 pound air pressure change due to its effect on handling. Cold race tire pressures often start in the low 20's and wind up in the high 30's when the tires are up to temperature. Load and ambient temperature have a dramatic effect on working (hot) tire temperatures. In racing, this affect is noticed most in oval tracks where the outside tires will show dramatic differences in the heat and pressure gains versus the inside tire. These changes affect the tires spring rate, contact patch, and the adhesive property (grip) of the tread compound in a very complex way.

I suspect that the point most miss is the tire temperature. Temperature is the real enemy for a tire. With my new (to me) Class A, I will start with Winnebago's recommended pressures and monitor both temp and pressure as the day progresses, and adjust accordingly. (higher temps will lead to higher pressures, but to correct a temp gain, you need to start with a higher pressure)

Just a newbie $.02 worth.
__________________
RandyMWV is offline   Reply With Quote
Old 06-18-2014, 11:03 AM   #34
Senior Member
 
Ford Super Duty Owner
Join Date: Feb 2011
Posts: 135
Education

For any of you who are not familiar, I strongly suggest spending some time with Roger Marble's blogs and tire info posts. The man has as good a tire credentials as anyone I know and can present info in a very understandable manner.
__________________
Peterd503 is offline   Reply With Quote
Old 06-18-2014, 03:55 PM   #35
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,715
Quote:
Originally Posted by RandyMWV View Post
As a car nut and former club racer, tire pressure is EXTREMELY important. While a Class A is very different than a 3000 pound race car, the extreme loading of the race tire has lessons for all tired vehicles.

A good race driver can easily distinguish a 1/2 pound air pressure change due to its effect on handling. Cold race tire pressures often start in the low 20's and wind up in the high 30's when the tires are up to temperature. Load and ambient temperature have a dramatic effect on working (hot) tire temperatures. In racing, this affect is noticed most in oval tracks where the outside tires will show dramatic differences in the heat and pressure gains versus the inside tire. These changes affect the tires spring rate, contact patch, and the adhesive property (grip) of the tread compound in a very complex way.

I suspect that the point most miss is the tire temperature. Temperature is the real enemy for a tire. With my new (to me) Class A, I will start with Winnebago's recommended pressures and monitor both temp and pressure as the day progresses, and adjust accordingly. (higher temps will lead to higher pressures, but to correct a temp gain, you need to start with a higher pressure)

Just a newbie $.02 worth.
You will find that the temp reading of most TPMS while moving is irrelevant, as they are being cooled by the ambient air moving past them. Only after you stop for several minutes will they indicate closer to actual tire temp. The pressures will increase 18-20% (115 psi to 137 psi) above the cold pressure before moving. All of mine increase about the same percentage above cold pressure. The temps never get close to the danger point.
__________________
Crasher is online now   Reply With Quote
Old 06-18-2014, 04:03 PM   #36
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,715
Quote:
Originally Posted by koda59 View Post
When I was an OTR driver our company kept all tires at 90 psi. We never adjusted our tire pressure, no matter what weight we were carrying.
Your company was doing the same thing we are doing. 90 psi was below the max pressure on the tire, but they have determined that 90 would carry the load and wear evenly. That also insured the best control and handling when loaded. That is exactly what I and others have done. Once the tire pressures are set for the maximum load each will carry, that's where they stay. Same as what your company did.
__________________
Crasher is online now   Reply With Quote
Old 06-18-2014, 04:23 PM   #37
Senior Member
 
DMTTRANSPORT's Avatar
 
Join Date: May 2014
Location: Henderson, Nevada
Posts: 1,225
Go to the Michelin web site, there's a reason the give you tire pressures for weight.....
__________________
2005 Newmar DS 4023, Spartan Chassis, ISL 370 Cumapart, 2008 Jeep Rubicon 4dr, 2015 Kia Soul, 1969 Italian & 2004 Akita
DMTTRANSPORT is offline   Reply With Quote
Old 06-19-2014, 12:22 AM   #38
Senior Member
 
jwmaustin's Avatar


 
Winnebago Owners Club
Freightliner Owners Club
Join Date: May 2013
Location: Nashville, IN 47448
Posts: 598
So I go to the doctor pretty regularly. I also have occasional (but more frequent than I want) tests as I get older. The nurses always take my BP. That's pretty important I guess because it's a part of your "vitals". As an engineer I always pay attention to measurements about me

Some will take the BP with a shirt on, some with a sweatshirt on and some bare (I mean me not the nurses). I have some use the cuff on the wall and some carry one with them because they don't trust the cuff on the wall. Some swear they should hold your arm, some don't. Some say that crossing your legs can affect the measurement. The other day I had BP taken once on one arm then repeated on that arm and taken on the other arm. The difference was about 10 from the first time to the second time. Sometimes I work out before I come but I'm not asked what I did previous to coming in.

My BP was 10 points higher than normal the other day and the doc said your BP is running a bit high. It is one of my vitals after all.

Makes me think of this article in Wikipedia: Distinction without a difference - Wikipedia, the free encyclopedia
__________________
Bill & Jenny - 2016 Winnebago Itasca Ellipse 42HD, 43 ft, Cummins 8.9 ISL - Blue Ox and SMARTCAR. Once/month traveler in Midwest and (as ofen as possible) Southern US. Home - Nashville, Indiana (Beautiful Brown County)
jwmaustin is offline   Reply With Quote
Old 06-19-2014, 09:12 AM   #39
Senior Member
 
Gordon Dewald's Avatar
 
Winnebago Owners Club
Join Date: Mar 2014
Posts: 10,152
Quote:
Originally Posted by slickest1 View Post
The off highway trucks that use central air systems use them for traction purposes only. My son drives a log truck with that system on it and they will drop the air to 50 pounds to climb a steep muddy hill. It gives an unreal amount of traction. They are lucky to get 3 months out of a set of tires.

I personally years ago sat through hrs and hrs of Michelin test track videos on running tires at different inflation pressures and I am firmly in the camp of running tires at the pressures stated on the sidewall.

If my coach needs a 14 ply tire to carry the weight then that is what I would put on it. I would not downgrade it to 10 ply just to think it would ride better.
I would not put a bigger heavier tire on and run it half flat either.
Nothing in the thread refered to changing tire ratings. It is a discussion about using the recommended tire pressures for the tires you have on the coach. The rating on the door of the coach is for the coach being loaded to GVWR and GAWR. I think you will find that the coach recommended pressure and the tire chart will be very close when the axle on the coach approaches max.

Traction in adverse conditions was one of the reasons to use the recommended tire pressure from the chart. You probably will have 'enough' traction for all the conditions you will encounter if you run tires at the max but why wouldnt you move towards max traction at the recommended pressure. Especially if you subscribe to the tires age out before they wear out.
__________________
Gordon and Janet
Tour 42QD/inTech Stacker
Gordon Dewald is online now   Reply With Quote
Old 06-19-2014, 09:27 AM   #40
Just south of Twin Cities
 
Cooperhawk's Avatar


 
Winnebago Owners Club
Freightliner Owners Club
Join Date: Jun 2013
Location: 5 miles south of Lakeville, Mn
Posts: 1,588
I drove tractor trailer for a number of years. We either ran empty, (25,000 lbs.), or fully loaded, (73.000lbs.) Each morning we thumped our tires with a hammer or club. If they thumped good we took to the road. If they thudded, we got them changed. We NEVER checked tire pressure!

I had trailer tires that had over 500,000 mile on them when they began to blow due to age.

My opinion is that folks are going into too much detail to maintain tire pressure. I use a TPMS to check my tires each morning, (I used to just thump them), and then it monitors tire pressure while on the road. I don't sweat the small stuff.
__________________
Retired FAA ATC,
VFW AL, VVA, NRA
2002 Journey DL 36, 3126 Cat 330hp
2015 Ford Explorer Blue Ox tow bar, AF1
Cooperhawk is offline   Reply With Quote
Old 06-19-2014, 01:09 PM   #41
Senior Member
 
DMTTRANSPORT's Avatar
 
Join Date: May 2014
Location: Henderson, Nevada
Posts: 1,225
Quote:
Originally Posted by Cooperhawk View Post
I drove tractor trailer for a number of years. We either ran empty, (25,000 lbs.), or fully loaded, (73.000lbs.) Each morning we thumped our tires with a hammer or club. If they thumped good we took to the road. If they thudded, we got them changed. We NEVER checked tire pressure!

I had trailer tires that had over 500,000 mile on them when they began to blow due to age.

My opinion is that folks are going into too much detail to maintain tire pressure. I use a TPMS to check my tires each morning, (I used to just thump them), and then it monitors tire pressure while on the road. I don't sweat the small stuff.
My thumper = 5 bucks, TPM, I don't know cause I have no use for one
__________________
2005 Newmar DS 4023, Spartan Chassis, ISL 370 Cumapart, 2008 Jeep Rubicon 4dr, 2015 Kia Soul, 1969 Italian & 2004 Akita
DMTTRANSPORT is offline   Reply With Quote
Old 06-19-2014, 01:19 PM   #42
Senior Member
 
Gordon Dewald's Avatar
 
Winnebago Owners Club
Join Date: Mar 2014
Posts: 10,152
Quote:
Originally Posted by DMTTRANSPORT View Post
My thumper = 5 bucks, TPM, I don't know cause I have no use for one
Thumping is an art and a skill. It certainly works in the morning and at any stops you make during the day. TPMS may tell you if you pick up a problem while travelling.

Lots of the OTR guys I know would thump their tires at every stop, some did not. However when a tire goes on an OTR it generally does not do a lot of damage other than air lines. MH seem to have a lot of important fragile stuff routed near the tire wells.
__________________

__________________
Gordon and Janet
Tour 42QD/inTech Stacker
Gordon Dewald is online now   Reply With Quote
Reply

Tags
tire pressure



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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tire pressures and overloading Ray,IN iRV2.com General Discussion 3 05-18-2014 06:27 PM
Tire Pressures 2014 Dutch Star 4369 jimfryar Newmar Owner's Forum 13 04-22-2014 09:20 AM
Tire pressures, extenders and airing up etc usdave1t Class A Motorhome Discussions 4 04-14-2014 11:02 AM
Tire pressures? Recommended seems very low. plasma800 Class A Motorhome Discussions 22 01-24-2014 10:27 AM
Checking MH tire pressures with/without removing wheel covers? mikecosgrove Forest River Owners Forum 3 01-22-2014 01:01 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:15 PM.


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