Skip to main content ↑ ↓
Topic: Individual tire weights (Read 776 times) previous topic - next topic

Individual tire weights

I finally was able to get my coach weighed at each wheel location.  I have Michellin XZA2 295 80R22.5 tires.  My weights are as follows:
Left steer-6,600lbs Right steer-6,900lbs
Left dual-9,600lbs Right dual 10,100lbs
Left tag 4,400lbs Right tag 4,500lbs

I have misplaced the info from Michelin.  Can anyone recommend inflation
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: Individual tire weights

Reply #1 –
What load range?

http://www.michelinrvtires.com/michelinrv/tires-retreads/load-inflation-tables.jsp

Oops - looks like that size is only in LRH

I think the general recommendation is 5-10 psi above heaviest axle end

Steer 105-110

Dual 85-90

Tag 75 (overkill but the chart doesn't go lower)

-M
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: Individual tire weights

Reply #2 –
Well even without the weights I have been running 110 steer 90 duals and 80 tag so I was really close.
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: Individual tire weights

Reply #3 –
The guy who weighed the coach suggested having FOT adjust the air bags to move some weight from the duals to the tag. Anyone know if this can be done and how.
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: Individual tire weights

Reply #4 –
Quote from: lavocat –
The guy who weighed the coach suggested having FOT adjust the air bags to move some weight from the duals to the tag. Anyone know if this can be done and how.

What percentage of GAWR are the steer, drive, and tag axles?  The tag on our '03 is rated at 9000 lbs.  We're running 7300 on it so 81%.  Our drive is at 16.6K of 21K, 79% and our steer is 12175 of 13880, 87.8 %

I might guess the ride height valve settings would be involved in adjusting those percentages.
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: Individual tire weights

Reply #5 –
Don't mess with trying to shift tire loads except by shifting cargo locations.  My weights are tire pressures are the same as yours.  The duals have the most excess capacity.  I don't think your weigh guy knew what he was talking about.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Individual tire weights

Reply #6 –
Michelle my tag GAWR is 10,000 and I am running 8900 or 89% so I really dont think I need to add anything there.
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: Individual tire weights

Reply #7 –
Quote from: lavocat –
Michelle my tag GAWR is 10,000 and I am running 8900 or 89% so I really dont think I need to add anything there.

There ya go! 

And a shout-out to Brett Wolfe as the one who clued me in to weight distribution/% GAWR back when we had our weights done.
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: Individual tire weights

Reply #8 –
Back when I had a SOB tag coach, the Freightliner factory service center in Gaffney told me adding weight to the tag also tended to shift weight to the front axle. So if anyone is running too close to front axle capacity they can decrease the tag weight which has the effect of transferring some weight off the front axle and increasing the load on the duals which usually have plenty of capacity.
Jeff & Patricia
Rescue dog Molly
Previous Foretravel owner

Re: Individual tire weights

Reply #9 –
Quote from: 2Escapees –
Back when I had a SOB tag coach, the Freightliner factory service center in Gaffney told me adding weight to the tag also tended to shift weight to the front axle. So if anyone is running too close to front axle capacity they can decrease the tag weight which has the effect of transferring some weight off the front axle and increasing the load on the duals which usually have plenty of capacity.
I must be missing something here. Moving weight further back decreases weight on the front axle. When I was hauling freight cross country living the trailer axles forward, essentially moving weight back, decreased tractor rear and front axle weight......or am I remembering incorrectly. ::)

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Individual tire weights

Reply #10 –
Roland, Think your referring to the 5th wheel position, here I think they are referring to A coach with a tag ale.  It is true with a tag axle you can add or retract weight to the drive ale and also slightly affect the steering weight, but only slightly as I see it.
I like enough wight on the steering to keep wheels from skidding in a turn such as a wet or slick road, while not overloading it..  As I keep saying there are massive opinions here .
Some real good and some lesser, again we all have opinions, so beware !

Re: Individual tire weights

Reply #12 –
Yes, taking more weight on the tag axle REMOVES weight from the drive axle and ADDS weight to the front axle.  Think of the drive axle as the fulcrum.

And, best balanced weights are the same percent of GAWR on each axle.  BTW, this can significantly effect handling.  At one of the Diesel RV Club Rallies, the rally gift was all wheel position weighting of each coach.  Of 5 tag axle coaches weighed, only one had close to the correct weight distribution.  Dick Lorntson (Precision Frame and Alignment) did the weighing and on the 4 tag axle coaches that weren't close we had them stop and open the engine bay. We then adjusted tag air pressure (these happened to all be Monaco products of one variety or another, and adjustment is quite easy).  All but one "passed" next time around.  The last one took one more fine tuning to get the percents on each axle within 2%.
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: Individual tire weights

Reply #13 –
Quote from: Roland Begin –
I must be missing something here. Moving weight further back decreases weight on the front axle. When I was hauling freight cross country living the trailer axles forward, essentially moving weight back, decreased tractor rear and front axle weight......or am I remembering incorrectly. ::)

Roland
Roland,
Think of a flat bed with a 9 foot  spread axle  with the lead axle being a air controled tag.  If you knew what you were doing, and could somehow cover the air exhaust sound, you could have all kinds of fun at the scales.
1994 U225
build #4514

Re: Individual tire weights

Reply #14 –
I suggest that there may be a difference in how different people are interpreting "moving weight to the tag axle." Weight can be moved there by physically shifting the load in the coach. It could also be moved by adjusting pressure between the tag axle and the structure of the coach while not moving any cargo. The two methods of "moving weight" would have opposite effects with respect to load on the other axles of the coach.

Brett's description of the adjustment on the Monaco coaches demonstrates adjusting pressure between the coach structure and the tag axle. Increasing the pressure on the tag would unload the drive axle and load the front axle. An example of changing distribution by moving cargo would be to move all the heavy stuff from the front of the storage bays to the rear of the storage bays. The would unload the front axle, and load both the tag and drive axles.

Brett, did I comment correctly regarding the two ways to "adjust load on the tag axle?"
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Individual tire weights

Reply #15 –
Quote from: J. D. Stevens –

Brett, did I comment correctly regarding the two ways to "adjust load on the tag axle?"

Absolutely correct.  While it would be great to physically move personal gear to the tag axle, the reality is there are VERY few coaches that have much storage that far aft.

Brett
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: Individual tire weights

Reply #16 –
Wondering what is the EXACT percentage of the total weight per axle ? 
Steer ?  Drive. ?  Tag. ?
There must be an exact number here  Or is it more opinion ??
This dummy is wondering.
 

Re: Individual tire weights

Reply #17 –
Dave,

That is a design question and varies by chassis.  Again, in an ideal world, each axle will carry the same PERCENT of its GAWR.

Different chassis have different GAWR axles, particularly in front and drive positions.  And, with the new rulings that allow more than 20,000 pounds on one axle for RV's, I suspect things will continue to evolve.
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