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Question of Weight Distribution

The last time I had my 09 42ft Nimbus weighted, the front was close to the max; the drive and tag had lots of available room for more weight to be added. So, the question is how does weight added to the storage compartments effect the weight on the front axle. I would think that as weight was added further away from the front axle the less weight would be added to the front axle.  I am thinking that I need to store the heaviest stuff as far back from the front as possible.  Am I thinking about this correctly?
Roy Dameron
Ex 2009 42ft Nimbus
Jeep Unlimited

Re: Question of Weight Distribution

Reply #1 –
That makes sense to me. I'm oversimplifying here, but weight behind the rear axle will be carried by the rear axle and a portion of it will actually be subtracted from the front axle. Weight forward of the front axle will be carried by the front axle and a portion of it will be subtracted from the rear axle. Weight directly over an axle will be carried by that axle. Weight between the axles will be shared by both, with the closer axle carrying the larger portion.

You probably want to move your anvil collection farther aft and your wife's feather collection farther forward. <grin>

Re: Question of Weight Distribution

Reply #2 –
Quote from: Roy Dameron –
I would think that as weight was added further away from the front axle the less weight would be added to the front axle.  I am thinking that I need to store the heaviest stuff as far back from the front as possible.  Am I thinking about this correctly?

You may also want to have your 3 ride height valve settings checked.  One up front, 2 rear.  I believe (trying to recall my old statics lectures) (and I hope Brett W. will chime in here with the correct info) if your ride height is low in front or high in rear it can cause extra load (weight) on the front axle.  You don't want to arbitrarily go changing them because you could mess up the handling, but you do want to make sure they're set up correctly.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Question of Weight Distribution

Reply #3 –
Yes, ride height is critical, particularly on a tag axle coach.

So, not only ride height (two on rear axle, one on front axle), but also how much weight the tag carries.  The more the tag carries, the more it transfers weight to the front axle.  It is a real balancing issue to get it right. 

Start with the basic ride height adjustment (front and drive axle), then weigh all three axles and see what fine-tuning you can do with the tag.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Question of Weight Distribution

Reply #4 –
I may be missing something, but on my 2005 the tag axle pressure is determined by the drive axle manifold. I see know way to increase tag axle pressure separately. I recently had a problem with a tag axle manifold solenoid not pressurizing the air bag.
Steve DeLange
2005 U320T 40'
Pearland, Texas

Re: Question of Weight Distribution

Reply #5 –
Good information everyone, thank you.

Roy
Roy Dameron
Ex 2009 42ft Nimbus
Jeep Unlimited

Re: Question of Weight Distribution

Reply #6 –
Steve,

You are correct-- not all tag axles are (easily) adjustable.  The easiest are Monaco products-- at the last Diesel RV Club Rally, we weighed all coaches (individual wheel positions).

100% of the tag axle coaches "flunked", meaning they did not come close to the ideal weight distribution. Ideal is for each axle to carry the same percent of GAWR.  With the Monaco products, PSI in the tag is easily adjustable from the back access panel.  We did the adjustments and had them return for another weighing.  Got calls from several a couple of hours later-- best their coach had ever driven.

I have not personally worked on any of the Foretravel tags, so do not know what is involved in changing weight distribution.  Hopefully someone has already done this and can post the how to.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Question of Weight Distribution

Reply #7 –
Very interesting thread.  The two times we have been weighted we were heavier in the front than I would like, if I could shift some of that weight toward the rear it would make me feel more comfortable.

Thanks for the idea.
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Douglas and Amanda
1997 40' U320 "Brawley"
2007 Ford Explorer Eddie Bauer
Motorcade #17266 Escapee #113692

Re: Question of Weight Distribution

Reply #8 –
Quote from: ScubaGuy –
Very interesting thread.  The two times we have been weighted we were heavier in the front than I would like, if I could shift some of that weight toward the rear it would make me feel more comfortable.

Thanks for the idea.

My fully loaded sister coach to yours needed 108 out of 110 pounds air in the front tires.
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Question of Weight Distribution

Reply #9 –
As far as the OP question, yes, move the heaviest stuff as far back as possible. Unfortunately, the weight of the coach itself means any weight shift will produce minimal changes. If you want to reduce the front weight significantly(>300 pounds), you are really going to move some significant weight.  In aircraft, I have moved batteries from the front to the rear to improve weight and balance issues.  In my 2005 coach, the batteries are in the center.  If I could find a more accessible location, I would move them, but all potential locations are more forward.
Steve DeLange
2005 U320T 40'
Pearland, Texas

Re: Question of Weight Distribution

Reply #10 –
Have you determined if the steering is favorable to you or not??  I prefer to be loaded a little on the high side forward so that steering is not an issue.  I don't know if you can overload the steering system with the coach being loaded a little heavy up front.  I have the tires to handle it and my steering sys is doing great.  The coach drives like a big car and doesn't get light in the front when going over those uppers and downers.  Hope it drives well for you  ----  Have a great day  ----  Fritz
Fritz & Kathy Johnson
1991 36'

Re: Question of Weight Distribution

Reply #11 –
Suggest weighing all wheels individually to establish a good starting point before making any adjustments, just saying.... ^.^d
Tony Pasquale
SOLD....
'99 U295 36'
WTFE, 04/99, #5572
Toad: 2020 Equinox

Re: Question of Weight Distribution

Reply #12 –
Quote from: Tony Pasquale –
Suggest weighing all wheels individually to establish a good starting point before making any adjustments, just saying.... ^.^d

Absolutely,

And the most "out of balance" RVSEF (RV Safety and Education Foundation) ever found was one with a bent ride height rod.  It transferred over 3000 pounds from one side to the other.  Luckily, they had weighted enough of that make and model to flag it, get it adjusted and re-weigh.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Question of Weight Distribution

Reply #13 –
Here's another "luckily"  fact.  When I had my coach weighed at fmca last January,  I was told the distribution was practically perfect.  He told me that is the norm for Foretravel,  but very rare in other brands.
Tom Lang K6PG (originally  KC6UEC)
and Diane Lang
2003 38 U295 build 6209
2016 Jeep Grand Cherokee Summit Ecodiesel
still have tow-ready 2006 Acura MDX 
Temple City, California
Motorcade 16681 California Chapter President
SKP 16663 member of SKP Park of the Sierra, Coarsegold California
FMCA F071251
Retired electrical and electronic engineer

Re: Question of Weight Distribution

Reply #14 –
foretravel was within 200 pounds left to right on average long ago.  the engineering dept overrode the marketing dept.  almost killed them
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4