[GMCnet] 2/4 bag installation
Len
I have the newest, latest and greatest dual bag system sitting in a garage,
purchased from Jim K. My son and I will attempt to install the system over
the weekend. If you want to watch and take notes on perhaps not how to do
it drop me a line at b52...@adelphia.com for day and time.
The worst was can do is document the installation for others to use.
Cheers,
Len and Pat
78 Kingsley, The Beast II with dash lights that work
Fallbrook, CA
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
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Jim Kanomata
Jim B, Tom Hampton,and Migil have been selling them along with us.
Replacement cost of the bags are half that of the origional.
We were overstocked with the Origional bags in June, now we will be
out by Spring.
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Dan Gregg
Anyone planning to hang onto their coach would be way ahead to replace the old bags with this system, when in need. No doubt about it. Later they can be upgraded to the quadrabag system for price of a few parts. I am sure glad that they have been made available.
Dan
--
Dan & Teri Gregg
///Halon Automatic Fire Extinguishers
Jim Bounds
There really is no reason any more for buying an original air bag or supporting those that are gouging our community with the price that want for them. It is better for you to go with the new systems and it's actually cheaper.
Someone might say "I onlt need 1 air bag". Do you replace shocks, brake pads, shoes, wheel cylinders and other parts by "each". No, the left side of the coach goes the same place as the right side so why should you only prepare one side of the coach with a new air bag. If one bag is near the end of it's life, it's a good bet that the other side is not far off and even if one bag seems good, heck put it up on Ebay and someone not understanding the dynamics of the issue will pay you big bucks for it and you will be upgrading the reliability of your coach in the meantime--- all of this is a win! So do not call me for a new original air bag, I'm off of them, I do have a couple of "good" used ones and I'l selling them cheap!
Wake up, the roses are sweet smelling!
Jim Bounds
---------------------------
Howard and Sue
You will do just fine.
Howard
Alpine
Happy Thanksgiving
Randy
Jim Bounds wrote on Tue, 24 November 2009 05:25
> There really is no reason any more for buying an original air bag or supporting those that are gouging our community with the price that want for them. It is better for you to go with the new systems and it's actually cheaper.
>
>
> Jim Bounds
Jim-
What experience have folks had with their new bag setup? I'm a die hard skeptic and need to see the pluses and minuses of just about everything. You've extolled the pluses, now are there any minuses that folks have run into that a prospective buyer should be aware of when making an informed purchase?
--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
Larry Davick
Perhaps a seasoned pro might find some fault, but I'm ignorantly blissful in my coach.
Larry Davick
The Mystery Machine
----- Original Message -----
From: "Randy" <Acros...@hotmail.com>
To: gmc...@temp.gmcnet.org
Sent: Wednesday, November 25, 2009 3:01:57 PM GMT -08:00 US/Canada Pacific
Subject: Re: [GMCnet] 2/4 bag installation
Larry Davick
What happens if one bag fails? Can the remaining bag be inflated enough to carry the coach, or are we dead 'till repairs are completed? I understand that the Quadrabag will hold up one wheel with the other flat, but what about the 4 bag?
Larry Davick
The Mystery Machine
Mike Miller
There are three different systems that use 4 airbags.
I believe the one being talked about here is the latest one (the cheapest system) and is mostly just a replacement for the original two bag system. The offical name is: "Dual Bag System". While not adding much (over stock) in features, the airbags can be bought off the shelf at almost any truck or auto parts store. They are available from either of the Jims (and maybe a few other places) for just under $800.00.
<http://appliedgmc.com/prod.itml/icOid/822>
On the other end of the scale is the "Quadra Bag Rear Suspension System" at twice the price at just under $1600.00. It has all the good features of any system using four bags. They only disadvantage over the other systems seems to be the price. (You do NOT get what you do not pay for.) Also available through the normal GMC parts channels. (Like the Jims.)
<http://appliedgmc.com/prod.itml/icOid/684>
The third system is the original 4 bag system that is priced between the two other systems. I believe they are still available, but I do not see it on Jim K's website. :roll: It is lighter than the Quadra Bag and does have a few "issues" when used in "non-standard" ways like running on 3 rear wheels.
ljdavick wrote on Wed, 25 November 2009 15:36
> Okay - so - I'm wondering out loud...
>
> What happens if one bag fails? Can the remaining bag be inflated enough to carry the coach, or are we dead 'till repairs are completed? I understand that the Quadrabag will hold up one wheel with the other flat, but what about the 4 bag? ...
So to answer your question:
Dual Bag: No
Quadra Bag: Yes
4-Bag: Maybe... depends.
--
Mike Miller
`73 26' X Painted D.
`78 23' Birchaven
Hillsboro, OR
Thomas Phipps
Leigh Harrison still has his 4 bag design availible. I believe the current price is about $1100. Check his web site.
Tom Phipps,
75 GMC Ex-Avion with only 2 air bags.
ken hugelier
BTW, Happy Thanksgiving to all.
ken, preparing for the first time, to spend extended time during the winter in Florida, hugelier
77 PB
Det. Mich.
Ken Burton
Jim Bounds wrote on Tue, 24 November 2009 06:25
> Another thought on this Greg, with the cost of a pair of new original air bags over $800, it is actually "cheaper" even up front to purchase the new dual bag system which "retrofits" your coach to the new "off shelf" air bags. If you go to sell your coach it will be a sales feature in that the coach will have been refitted for the future-- new owners will have to do this refit themselves before they can deem their new purchse reliable. At that, you can upgrade the system to the superior performing Q-bag system for a little more at a later date if you have to spend $ in steps.
>
> There really is no reason any more for buying an original air bag or supporting those that are gouging our community with the price that want for them. It is better for you to go with the new systems and it's actually cheaper.
>
> Someone might say "I only need 1 air bag". Do you replace shocks, brake pads, shoes, wheel cylinders and other parts by "each". No, the left side of the coach goes the same place as the right side so why should you only prepare one side of the coach with a new air bag. If one bag is near the end of it's life, it's a good bet that the other side is not far off and even if one bag seems good, heck put it up on Ebay and someone not understanding the dynamics of the issue will pay you big bucks for it and you will be upgrading the reliability of your coach in the meantime--- all of this is a win! So do not call me for a new original air bag, I'm off of them, I do have a couple of "good" used ones and I'l selling them cheap!
>
> Wake up, the roses are sweet smelling!
>
> Jim Bounds
I have a good friend that had a 77 transmode. He called me one day because he blew an air bag. I told him to get two and I would help change them. He only got one and we changed it. 8 months later in the hot July sun we were along the road changing the second one that blew out. It would not come off and we ended up getting flame wrench to remove it. I would have much rather have changed them both at the same time under more pleasant conditions.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Randy
What parts are common to the Dual Bag and Q-bag that allows upgrading in steps?
--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
Shan Rose
im interested n this as well since one of my bags looks like it will need replacement soon...
Luvn737s wrote on Thu, 26 November 2009 15:51
> What parts are common to the Dual Bag and Q-bag that allows upgrading in steps?
fred veenschoten
Luvn737s wrote on Thu, 26 November 2009 15:51
> What parts are common to the Dual Bag and Q-bag that allows upgrading in steps?
the bags!
--
Fred V
'77 Royale RB 455
P'cola, Fl
John Wright
center mounting support that keeps the bags in alignment is not uses
in the q-bag setup. You can upgrade from the 4 bag to the q-bag for
about $800 more.
J.R. Wright
GMC GreatLaker
TZE Zone Restorations
77 Eleganza Custom (For Sale)
1975 Avion (Under Reconstruction)
Michigan
Gary Casey
the bump. True? Trying to decide which version to get.
Gary
Luvn737s wrote on Thu, 26 November 2009 15:51
Gary Casey
If so, that still brings up a question when running on one wheel - I presume the bag would have to run at twice the normal pressure in order to hold up twice the weight. What is the normal pressure and will there be enough system pressure to supply double that? Will the bag tolerate the higher pressure?
Gary
________________________________
From: Gary Casey <casey...@yahoo.com>
To: gmc...@temp.gmcnet.org
Sent: Fri, November 27, 2009 5:45:01 AM
Subject: Re: [GMCnet] 2/4 bag installation
Another question about the various bag setups: When I read the ads for any of the replacement designs it seems that "increased stability" is always mentioned, but never is there an explanation as to why that occurs. Any spring only has a force and the spring rate that can affect anything and the force exerted by all the designs has to be the same. So the spring rate must be different. But what is it? I can't find any mention of the difference in rate. Of course, the rate of an air bag varies with travel and static pressure since the volume changes, but at the design ride height there should be a number. And I would think that whether the bags are common (as in the 4-bag setup?) or rigidly supported at the center I would guess the characteristics would be the same regarding ride and handling. When moving slowly over a large bump the common setup as in the original design would presumably have an advantage as the wheels could "walk" over
Steven Ferguson
About .two months ago I replaced my Harrison setup with the Quadra bag
setup. Both systems provide a very significant amount of stability.it
Is without a doubt the single best improvement I have made to coach
handling. Driving onto the shoulder and back onto the road again is
no different than doing the same with a car. Truck influence is
significantly reduced as are the adverse effects of high cross winds.
In other words, everything got better.
All of the shortcomings of the Harrison system are are corrected with
the Quadra bag system. Wheras the Harrison cuts over an inch from
full "raise", the Q-Bag setup restores it. The Harrison setup
required changing out my compressor controller and check valve to
handle the 130 psi required to maintain the travel position and get
the coach leveled at some campsites. Both sides were well over 105
psi to maintain "travel". The Q-bag needs about 85-90 psi to maintain
the "travel" positon and about 120 psi for full raise for leveling. I
had two tire problems with the Harrison setup and both resulted in
bending the supports while driving a very short distance to a safe
place to change the tire. The supports for the Q-bag setup are
massive by comparison and with the additional inch or more of "full
raise" available, a jack stand and hook would easily slip under the
bogey casting to facilitate changing a tire without a jack. I
straightened and reenforced the bent uprights on the Harrison system
in hopes that next time wont result in bent pieces but the welding
destroyed the cad plating. It appears that the bag supports on the
Q-bag setup are more than twice as thick and strong but hopefully,
there will be no more dynamic testing done with my GMC.
My 12vdc compressor that sustains air pressure underway is really
flagging after just a few years. That extra 30 psi requirement just
slaves that thing (Thomas 317) and it now will only get up to 90 psi.
I am currently looking for another 12vdc compressor and am looking
hard at the ZenithAir units. Gonna have to save up for that though
as they are expensive.
As far as ride quality is concerned, I honestly cannot tell the
difference between the two systems. You would think it would be just
the opposite with one system requiring 110 psi and 115 psi compared to
85-90 psi on the other system. Both offer the same ride quality as
the OEM system did and both offer uncomparable stability over the OEM
system. Unfortunately, I cannot say why this is but I would bet that
the individual supports for the bags has a tendency to limit bogey
travel in the horizontal plane.
On Fri, Nov 27, 2009 at 4:45 AM, Gary Casey <casey...@yahoo.com> wrote:
> Another question about the various bag setups: When I read the ads for any of the replacement designs it seems that "increased stabiliAbout ty" is always mentioned, but never is there an explanation as to why that occurs.
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
Steven Ferguson
The Aulger double bag setup is an excellent alternative for the OEM
setup. It is a bolt in (really) deal and was designed to replace the
OEM setup as the bags become more and more scarce. It was never
designed to allow driving on one wheel. Since the bags are the same
as the ones used in the QBag system, a future upgrade to the QBag
system can be made using those bags. I believe I have read here where
the vendors will sell the QBag system sans bags.
To answer your question re inflation pressures required to drive with
one wheel off the ground with the Harrison or QBag system, it is not
double. With the Harrison setup I was able to get the wheel off the
pavement by inflating the other bag to 140 psi (my 120VAC compressor
easily handles 150 psi). With the addiditonal travel in the QBag
setup, I can easily get one wheel off the ground with the air pressure
afforded by the OEM compressor. (120 psi). The new Firestone bags
are more than up to the high pressures.
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
Ken Henderson
> IMHO, Steve's touched lightly on the reason for increased stability with
> 4-bag or Quad-bag:
>
> "... I would bet that
>
>> the individual supports for the bags has a tendency to limit bogey
>> travel in the horizontal plane."
>>
>
> that the forces applied to a center wheel are telescoped to the adjacent
> rear wheel. The pedestal between the fore and aft bags in the modified
> suspensions eliminates that transfer of forces. We usually think only of
> the vertical forces on the wheels and the elimination of their effects.
> Fact is, the horizontal forces are also significant: With the OEM system,
> if a center wheel is deflected to the left, the rear wheel is, through the
> single air bag, deflected to the right (or maybe to the left -- hard to be
> sure intuitively). While the effect of that may be slight, it does exist;
> with our flexible suspension arms and wear-prone pivot pins, it probably is
> enough to cause considerable adverse steering effect. The center pedestal
> should effectively eliminate that horizontal movement "echo".
>
> JMHO,
>
> Ken H.
>
>
>
>
>> On Fri, Nov 27, 2009 at 4:45 AM, Gary Casey <casey...@yahoo.com> wrote:
>> > Another question about the various bag setups: When I read the ads for
>> any of the replacement designs it seems that "increased stabiliAbout ty" is
>> always mentioned, but never is there an explanation as to why that occurs.
>>
>
Steven Ferguson
Hal Kading
I believe the two air bags on each side act quite independently of each other because of the restriction to the air flow between them in the quadrabag setup vs the original unrestricted single bag. This in turn has a dramatic effect on how the wheels react to bumps, ruts and pavement edges because each wheel acts quite independent of the other. It is a very different suspension system for the rear wheels than the original.
Hal Kading 77 Kingsley 455 with quadrabag and 78 Buskirk Stretch with Harrison Stretch 4 bag system, Las Cruces NM
Jay Rabe
any direct comment/response to the question?
> When moving slowly over a large bump, the common setup as in the original design would presumably have an advantage
> as the wheels could "walk" over the bump. True?
J "soon to be an owner" Rabe
_________________________________________________________________
Windows 7: I wanted simpler, now it's simpler. I'm a rock star.
http://www.microsoft.com/Windows/windows-7/default.aspx?h=myidea?ocid=PID24727::T:WLMTAGL:ON:WL:en-US:WWL_WIN_myidea:112009
Steven Ferguson
systems do it better as the action of each wheel has no effect on the
other wheel.
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
jim kanomata
Should one bag on a Duel Bag go out, you can inflate the opposing bag to a higher pressure and drive.
We will need to do this and figure what pressure is the max that we can fill.
You will not be able to get it up to the same height with one bag, sheet tells me to not extend one bag more than 10", pressure to not exceed 150psi.
--
Applied/GMC, Fremont, CA
1-800-752-7502
ji...@appliedgmc.com
www.appliedgmc.com
Mr.erf ERFisher
the whole idea of the "bogie" system, is that the first wheel to hit the
bump only goes up 1/2 of the bump height because of the lever arm and the
connected air bag.
In the 4bag system, the wheels operate like seperate axlels, and the first
wheel to the bump, lifts the coach the whole height of the bump since the
bags are only slightly air connected. This accentuates the bump.
Now which is more stable, is up to you ......
gene
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
Jay Rabe
Do all of the varieties - the "4-bag," the "dual bag," the Leigh Harrison system (is this the same as the 4-bag?), and the Q-bag - operate the same in the way they go over bumps?
J
> Date: Fri, 27 Nov 2009 13:02:56 -0800
> From: mr.er...@gmail.com
> To: gmc...@temp.gmcnet.org
> Subject: Re: [GMCnet] 2/4 bag installation
>
Jim Kanomata
The common part for QBag/Duel Bag:
4 Bags with fastners
4 Adapter plate wth nut
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Rob Mueller
When I was at the Santa Rosa rally I saw a coach make a right turn out of
the parking lot. The down ramp was short and the road was crowned. The top
of the middle tire was angled in and the bottom out. The rear wheel was the
opposite.
I thought there was something wrong with the rear suspension on that coach
and mentioned it to a number of people and they all told me that was normal.
I have no idea what kind of suspension system it had on it.
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of Ken Henderson
Sent: Saturday, 28 November 2009 12:45 AM
To: gmclist
Subject: Re: [GMCnet] 2/4 bag installation
One of the characteristics of the OEM setup, promoted as an advantage, is
that the forces applied to a center wheel are telescoped to the adjacent
rear wheel. The pedestal between the fore and aft bags in the modified
suspensions eliminates that transfer of forces. We usually think only of
the vertical forces on the wheels and the elimination of their effects. Fact
is, the horizontal forces are also significant: With the OEM system, if a
center wheel is deflected to the left, the rear wheel is, through the single
air bag, deflected to the right (or maybe to the left -- hard to be sure
intuitively). While the effect of that may be slight, it does exist; with
our flexible suspension arms and wear-prone pivot pins, it probably is
enough to cause considerable adverse steering effect. The center pedestal
should effectively eliminate that horizontal movement "echo".
JMHO,
Ken H.
Jim Kanomata
It does not make any difference as to std or Q bag as the arm mount
and the wheel spindle is not changed.
If you have a worn rear boggie pin/arm, the wheel will tent to show
more slant. Also the amount of friction and how sharp it is making the
turn.
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Ken Henderson
I'm surprised that with the coach making a Right turn the Top of the Middle
tire was In. I'd have predicted the opposite by this logic:
Draw 3 tire patches like the GMC's in a turn, then imagine the center of the
turn arc being half way between the middle and rear patches. For the tires
to follow the radial from that center to the center of the right-turned
front wheel, the middle tire must slide to the right, with rotation about
the suspension arm forcing the Top of the tire Out. Conversely, to follow
the extension of that radial, the rear tire must slide toward it, forcing
the tread Out and the top In.
Maybe the crown of the road reversed the appearance?
Ken Baffled H.
--
Ken H.
Americus, GA
'76 X-Birchaven
www.gmcwipersetc.com
Len
forward once you see how it goes together. He id thinking about taking
pics while we do the other side tomorrow.
Next project......tires as well as install a window with a screen in the
door.
Len and Pat
78 Kingsley, The Beast II with dash lights that work
Fallbrook, CA
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of jim kanomata
Sent: Friday, November 27, 2009 12:57 PM
To: gmc...@temp.gmcnet.org
Subject: Re: [GMCnet] 2/4 bag installation
Ken Burton
I think you guys are dreaming if you think you will get very far with only one rear wheel of the pair on the ground. My coach weighs approximately 4000 pounds per side on the rear. This means if I am running with only one wheel on a rear side it needs to handle the whole 4000 pounds. If I remember correctly the max weight rating of a 2.25x75x16 LRE tire is 2680 pounds and that is at 80 PSI which none of us run at. I have seen no one mention adding additional air to the remaining tire on the ground. Even if you aired it to it's maximum of 80 PSI you are asking that remaining tire to handle an additional 1300 to 1400 pounds or about 50 % above it's rating.
I would not go more than a few hundered feet in that configuration.
Has any one really done this? If so, how far did they go?
JMHO
Ken B.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Mr.erf ERFisher
http://www.gmcmhphotos.com/photos/showphoto.php?photo=1035
gene
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
Ken Burton
Mr ERFisher wrote on Sat, 28 November 2009 03:37
> there was always this one, that is running around in N. CA. some where
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=1035
>
> gene
I've seen photos of that coach before. I wonder what they did to lighten up the rear or to beef up the rear suspension.
Rob Mueller
I've played the memory over in my mind and I could swear that it occurred
the way I noted.
Frankly I think that the fact that the ramp went down and the road went up
played a greater effect than the right turn.
Perhaps the middle wheel was on the up part of the crown and the rear wheel
was on the down part of the ramp?
Top in bottom out bottom out top in the bottom line is that the wheels were
NOT parallel with the sides of the GMC and that was what blew my mind.
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of Ken Henderson
Sent: Saturday, 28 November 2009 12:31 PM
To: gmclist
Subject: Re: [GMCnet] 2/4 bag installation
Rob,
I'm surprised that with the coach making a Right turn the Top of the Middle
tire was In. I'd have predicted the opposite by this logic:
Draw 3 tire patches like the GMC's in a turn, then imagine the center of the
turn arc being half way between the middle and rear patches. For the tires
to follow the radial from that center to the center of the right-turned
front wheel, the middle tire must slide to the right, with rotation about
the suspension arm forcing the Top of the tire Out. Conversely, to follow
the extension of that radial, the rear tire must slide toward it, forcing
the tread Out and the top In.
Maybe the crown of the road reversed the appearance?
Ken Baffled H.
Steven Ferguson
After the GMCWS Estes Park rally, I drove from exit 243 (I-25, CO. Rd
119) to exit 240, a distance of around 3 miles. I pulled into a
restuarant parking lot so I could pull the rear-RS wheel off and get
the tire repaired. It bent the upright support but not so severely
that I couldn't finish the journey home afterward. The level sensor,
not knowing that the support was bent, compensated and maintained the
correct ride height for the trip home. Earlier this year, on the way
to GMCWS in Palm Desert, CA., I hit a road hazard and blew the forward
RS rear and again had to drive to a safe place to change the tire.
Same procedure, air down the bag for the bad tire, air up the other
bag enough to lift the bad tire off the ground. Since I had
straightened and reenforced that support after the previous disaster,
it did not bend during the less than one mile drive to an empty
parking lot. All of the above was with the Harrison system. Next
rally you're at, I'd be glad to do a demo with the Quadra Bag setup.
It is much sturdier and I don't see how it could bend or distort. I
had to put 150 psi in the bag to lift the bad tire. With the Harrison
setup I have routinely had to use as much as 150 psi to level in some
situations. I also routinely used that much air to full raise the
coach to get supports under the bogey castings for storing the coach.
There's no question in my mind that the bags can handle it. My GMC
weighs about as much as yours.
On Fri, Nov 27, 2009 at 10:22 PM, Ken Burton <n9...@comcast.net> wrote:
>
>
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
Nelson Wright
I think thats Ken's concern is more with the overload of the remaining
tire. Having exceeded the load rating on trailer tires I would have to
say that you can get by for a while but the long term life of the tire
may have been shortened. Also think about the fact that we determine
the load on each tire by weight when sitting level and still, and
ignore the load that results from weight transfer when going around
long turns or uphill. So going straight and slow on one rear tire
should be OK, but if you have the opportunity to increase the tire
pressure I would do so.
BTW did you mention that you had reinforced your Harrison weldment? If
so do you have any details or photos that you can share?
Nelson Wright
Orlando, Fl.
78 Royale rear bath
> There's no question in my mind that the bags can handle it. My GMC
> weighs about as much as yours.
>
> On Fri, Nov 27, 2009 at 10:22 PM, Ken Burton <n9...@comcast.net> wrote:
>>
>>
>> I think you guys are dreaming if you think you will get very far
>> with only one rear wheel of the pair on the ground. My coach
>> weighs approximately 4000 pounds per side on the rear. This means
>> if I am running with only one wheel on a rear side it needs to
>> handle the whole 4000 pounds. If I remember correctly the max
>> weight rating of a 2.25x75x16 LRE tire is 2680 pounds and that is
>> at 80 PSI which none of us run at. I have seen no one mention
>> adding additional air to the remaining tire on the ground. Even if
>> you aired it to it's maximum of 80 PSI you are asking that
>> remaining tire to handle an additional 1300 to 1400 pounds or about
>> 50 % above it's rating.
>>
_______________________________________________
Steven Ferguson
I think I emhpasized that airing up one bag and deflating the other
was for getting to a safe place for repairs.. At least I hope it came
across.
The forward upright support was bent over so far that the top was
touching the rear upright. Not wanting to remove the entire assy from
the coach, I put a short bolt and nut between them and turned the bolt
counter clockwise until I was able to get a longer bolt and nut in and
kept doint this until the support returned to it's original location.
Then I welded the "spreaders" in place. I have recommended to others
that they attach the two uprights with a brace welded around the
perimeter but leaving access to the air fittings. The next tire
problem I had on that side required the same emergency procedure and
the support brackets both took a bit of a lean, but didn't bend
permanently.
Am I making sense Nelson?
Steve
Steven Ferguson
I think thats Ken's concern is more with the overload of the remaining
tire. Having exceeded the load rating on trailer tires I would have to
say that you can get by for a while but the long term life of the tire
may have been shortened.
No pics Nelson. Jim K has the entire setup now.
As far as the tire goes, I aired it up to 80 psi and hoped for the
best. No problems with the tire and it aged out of service
gracefully.
Steve
Nelson Wright
On Nov 28, 2009, at 11:13 AM, Steven Ferguson wrote:
> The forward upright support was bent over so far that the top was
> touching the rear upright. Not wanting to remove the entire assy from
> the coach, I put a short bolt and nut between them and turned the bolt
> counter clockwise until I was able to get a longer bolt and nut in and
> kept doint this until the support returned to it's original location.
> Then I welded the "spreaders" in place. I have recommended to others
> that they attach the two uprights with a brace welded around the
> perimeter but leaving access to the air fittings.
> Am I making sense Nelson?
I get the idea, but one picture would be worth " well you know"
Thanks,
Nelson
jim kanomata
Gary,
The biggest differance is in our design we operate on lower air pressure to give you the same smooth ride that ladies like.
Major complaint of the Harrison unit.
Some felt they wanted better handling with the rough riding unit.
Q Bag was origionally developed in Texas by Ken Rose to overcome the harsh ride and still have stability.
The bags and the way it is utalized gives it a different spring rate.
If you hit the side of a coach with really strong wind, both units will lift up on one side. Harrison and Q Bag will behave the same.
The Q Bag mounts on to the pins much more secure as it utilizes a machined nuts and plates.
Also you'll notice that our bag is centerd. That is why our will not twist or bend. We had the back brace desidned just for that.
Q Bag was all don on CAD so we get the best design possible.
--
Applied/GMC, Fremont, CA
1-800-752-7502
ji...@appliedgmc.com
www.appliedgmc.com
Steven Ferguson
Darned if I didn't take a couple of photos. Here you go:
http://www.gmcmhphotos.com/photos/showphoto.php?photo=19033
On Sat, Nov 28, 2009 at 8:37 AM, Nelson Wright <f25c...@earthlink.net> wrote:
> I get the idea, but one picture would be worth " well you know"
>
> Thanks,
>
> Nelson
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
Carleton Douglas
I am going to do that to my Harrison 4 bag, before it happens to me.
Now that we know what has and will happen it can be corrected by each
owner with very little effort.
Jim the sky is not going to fall in on us.
Thanks
--
Carleton Douglas
73 custom, by myself
Prescott, AZ
Kosier
Actually, it's not really that bad. The effect is what the
circle-trackers call "wedge". The front corner on that side and
the opposite rear corner
become more heavily loaded, thus taking part of the load off the
low corner. It's the same effect as when you manually raise one
rear bag too
high and go down the road. That corner and the opposite front
corner carry a larger percentage of the weight. Alex Sirum's
scales have shocked
many people, me included, who were running with the rear
misadjusted.
Gary Kosier
77EII & 77PB
Newark, Ohio
----- Original Message -----
From: "Ken Burton" <n9...@comcast.net>
To: <gmc...@temp.gmcnet.org>
Sent: Saturday, November 28, 2009 1:22 AM
Subject: Re: [GMCnet] 2/4 bag installation
>
>
Jim Bounds
Guess mainly because I have been messing with 4 bags for a very long time, here are a few comments on what I have seen:
o I agree that you do not want to drive forever with one wheel down but you can at least drive it far enough to do the repairs on "your terms" than on the side of the road in some ant bed or something. Going to Dothan, we caravaned and one coach had 2 flats where he drove twice to safety-- it works-- the Q bag system did a great job, there were witnesses!
o The Q bag system was created basicallt because we had found the other system out had issues. Nelson had been talking with me about doing a fix for the other system. I feel it would be a very important refit and I feel we will have that upgrade soon. Steve was the one who convinced me something like that would be needed.
o The dual bag is at least a retrofit to kepp our coaches on the road, it is a good thing for all of us. I would certainly prefet to see a Q bag used but at least we are no longer held hostage by the "forces of evil" who are trying to hold us hostage selling original air bags at inflated prices. We should just say no to that.
o Our adjustible air ride suspension is a great driving aid-- up in town to keep our bumpers safe, low in the back to give us superior driving characteristice on the highway-- we all should use our air ride system. New, better compressors, new design air bag systems-- 2 to choose from, JR's valves for the power level system-- we are really blessed with an awesome suspension. Retrofit the system and use it.
o I feel bad that the early system has shown itself to be weak after I had installed so many of them, it's too bad those problems were not addressed before this. I want to help everyone who has that system, this is why I think a fix for it is really needed
Jim Bounds
-----------------------
Carleton Douglas
problems with his system? It seems that a lot of people are talking
around and about them but to them. These are your customers and
suppliers you also owe them elegance. As a reminder that was a very
expensive purchase and no one is will to stand up to them. I called
them and they said they had no problems with their unit.
--
Carleton Douglas
73 custom, by myself
Prescott, AZ
Len
The hardest part was removing the two sheared off bolts in the T skirt
brackets. Having the pic up on the screen from Jim K's site helped quite
a bit.
Cheers,
Len and Pat
78 Kingsley, The Beast II with dash lights that work
Fallbrook, CA
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of Len
Sent: Monday, November 23, 2009 6:50 PM
To: gmc...@temp.gmcnet.org
Subject: [GMCnet] 2/4 bag installation
All,
I have the newest, latest and greatest dual bag system sitting in a garage,
purchased from Jim K. My son and I will attempt to install the system over
the weekend. If you want to watch and take notes on perhaps not how to do
it drop me a line at b52...@adelphia.com for day and time.
The worst was can do is document the installation for others to use.
Cheers,
Len and Pat
78 Kingsley, The Beast II with dash lights that work
Fallbrook, CA
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
_______________________________________________
Jim Kanomata
In some ways that will be true as the location of the bags are same as
the Q Bag and the bags are identical.
Only that the bag is not isolated for one wheel.
On Sun, Nov 29, 2009 at 2:53 PM, Len <B52...@adelphia.net> wrote:
> My son and I finally got the system installed, took about 4 hours total.
> The hardest part was removing the two sheared off bolts in the T skirt
> brackets. Having the pic up on the screen from Jim K's site helped quite
> a bit.
>
> Cheers,
>em
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Howard and Sue
See I told you.
You could do it.
Howard
----- Original Message -----
From: "Len " <B52...@Adelphia.Net>
To: <gmc...@temp.gmcnet.org>
Sent: Sunday, November 29, 2009 2:53 PM
Subject: Re: [GMCnet] 2/4 bag installation
Jim Bounds
While I appreciate your comments, I had contacted Leigh time and again expressing the problems my customers were having, had one system on a stretch that was sold to a customer overseas. I drove the coach to Jacksonville from orlando-- had a blowout and found when I arrived at the port there was a 10mm deflection of the center support. I could not do anything in that I was literally sitting at the docks having the coach being strapped to the deck of the ship. The owner had to fix it in England. Told Leigh about it and he blew me off.
I have no doubt I had installed more of the systems than anyone and had found several issues with them, tried to give my constructive input but was also told he had seen no problems-- can;t help that I HAD! There were manufacturing issues, things that if causing damage or fatalities linked to them might come back on me so I refused to install the systems any longer. As a shop, I cannot install something knowing there are problems or at least issues.
After installing them for so many years, I felt I was qualified to make improvements and when Jim K. expressed the desire to get involved, having the manufacturing capability, I threw in with him feeling I knew the issues well enough to aid in the design phase. Jim and others, I gotta tell ya, did an awesome job of design and testing. Computer failure testing showed up the issues, my only wish is I wish I had done it years ago! All the problems I saw were not only addressed but we were able improve upon them. The bags used have more throw and higher weight handling specs., the movement up and down is better, the pressures used to achieve that are less, the structure is stronger and the plating finish is superior. We went through some more discovery after starting in on the Q bag system, nothing even remotly near the reliability issues I had been dealing with before and now I gotta tell ya the Q bag set up is the "bees knees" as the
commercial says!
I cannot help that this product is an improvement-- it was supposed to be! I did all I could to work with the old system but with no response had to seek another path and it worked out. Now, in looking at what we had discovered over the years of perfecting the Q bag, I'm now wanting to somehow improve the older system for all of those friends of mine out there that have it. Heck, I have one on my coach and without tossing the big bucks I spent even I would love to make the system I'm riding around on sfer and more reliable. Nelson & I have been talking about it for some time now-- Nelson has a set just like Steve did so we're looking to help ourselves at the same time offer this option to others-- that is if we can actually accomplish the goal! I feel the 1/4" steel can be reinforced at key places to stop the deflection-- of course it will need to be subjected to the same failure testing the Q bag system was. There are many of the
systems out there so there is enough call for this retrofit to make it worthwhile. There is hope, there is more to consider than the deflection issue. Maintenance and performance issues I think can be improved and we're looking at a refit that will address all of it at the same time. I'm again looking to include Jim K., his testing and manufacturing capabilities into this refit. I would caution you to not just throw this or that at it, let us go through the process and try to figure it all out. The rear suspension is an important system and cause dangerous issues -- that has been proven from the past probelms. Don;t go at this "grass roots", stand by.
If the manufacturer is not interested in improving his product to a more reliabble state, we'll do it! If it is said there has been seen no problems with the system to date, that pretty much answers that question. You hit the same brick wall I did, being in the business though I cannot just let it go-- and I won't!
See, the specialty dealer network is all in this together, we must do the things that keep our valuable customers safe-- heck, you guys are all we have! Jim K. understnads this and we all are working for you-- at least we are. Jim K. is stepping up to the plate, man he owes me $5 for promoting him like this! Being focused more on restoration and all that goes with that, Jim K. has IDed the focus of parts supplier and has done the things needed to be such. I am supporting his efforts, yes I sell parts too but we do not comete on parts. I have mine, he has his and we support eachother. Jim K. is the one with the most to loose on so many parts-- big ones, rims, suspension stuff, motor mounts, height control valves-- the list goes on. I used this line once before but "who else" is committing his assets in this direction-- I am relying on him as you should too. The Q bag and the dual bag are integral to keep our coaches on the road. The
older system needs refinment and I am hoping to again pair with Jim K. to produce that.
Hope I answered your comment-- probably drove it through the ground, I just live with these issues every day-- sorry
Jim Bounds
---------------------------
Carleton Douglas
Now that this is out in the air I would like to have a list of areas
that are effected.
Steve's fix makes a lot of sense and is a easy fix, what ever is the
last word on this be sure that each owner can take his unit off and
have it fixed (modified) per a drawing that you or someone comes up
with.
Would a letter writing complain help if we were to do one, pressure
from customers has to mean something to Harrison. There are DOT
problems with this item so we have a leg to stand on.
To tell you the truth I like some of Harrison's products but the
welding is pure carp, who ever is doing his welding does not know what
he is doing, just trying to make look good, a shallow under cut weld
will crack by it self, if that were the root pass it would be good and
then a filler pass, as is pure junk.
I guess the bottom line is we paid for junk and should get our money
back or a good product.
Thanks Jim for the info, I bought my set from Harrison after talking
to you, you sent to Harrison.
Jim Kanomata
I have the old 4 bag that SteveF modified.
I'll meet with our designer and see if we can produce a repair kit for
the Harrison unit.
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Larry Davick
Let us know your impressions about the new bags once get going down
the road.
Larry Davick
The Mystery Machine
Ljdavick at comcast.net
Carleton Douglas
Bob de Kruyff
""On Fri, Nov 27, 2009 at 10:54 AM, Jay Rabe <mailto:jay...@hotmail.com> wrote:
>
> any direct comment/response to the question?
>
>> When moving slowly over a large bump, the common setup as in the original design would presumably have an advantage
>> as the wheels could "walk" over the bump. True?
>
> J "soon to be an owner" Rabe
Jim--surprisingly a lot of the impact feel that you get when going over a bump comes from the suspension geometry more than the spring rate. The wheel wants to move up and back when it hits a bump. Unfortunately on our coaches, the leading arm moves up and forward. Additionally, the tires and suspension bushings have a large effect. Because of the inertia involved in moving all of that stuff, the tire rate becomes important and actually "envelops" a bump. Spring rate primarily affects ride rate (ride frequency) and roll rate.
--
Bob de Kruyff
78 Eleganza
Chandler, AZ
Jim Bounds
The theory of the rear suspension "creeping" over bumps is all well and good and I understand it but in the real world there are few speed bumps to hit that would actually put the see/saw suspension into action. Over the years I have found that there is a "marshmellow" sort of ride in the rear and that isolating each wheel with it's own air bag not only gives you a less mushy ride but also gives you more stability. I the past with @ 130+ plbs of pressure in the older 4 bagger, that translated to a stiffer ride. On the lower pressure Q bag system, you get the stability without the stiff ride. Anyone who has the system will tell you this is true-- anyone out there that has experienced this could chime in and explain it in their own way.
Also not having to lay in a bed of ants while changing a blown tire is a good thing. Those at the Dothan rally saw a day after that event happened how easy a flat was to deal with.
If you still feel that you want both wheels to push agianst themselves-- hey, we live in America so pick up the "dual bag" system and you will remain "Same as it ever was". I have installed enough of these and have heard enough to say the Q bag is the bomb but you can do it anyway you want. Whatever you want to believe you myust know that sooner or later you will have to refit your coach for the newer bags-- sorry but that will be!
After more than a decade of running 4 bags, I have to say there are no problems doing it, that is if the system is designed to not fail!
Jim Bounds
Jim Bounds
It should not take more than a couple of hundred yards to tell new things are going on. The best test to me is to drive like you are driving a smaller vehicle and I think you willl find your coach that much more responsive with a firm ride-- no mush and a rail like straight drive.
Good luck,
Jim Bounds
------------------------
----- Original Message ----
From: Larry Davick <ljda...@comcast.net>
To: "gmc...@temp.gmcnet.org" <gmc...@temp.gmcnet.org>
Sent: Mon, November 30, 2009 3:06:05 PM
Subject: Re: [GMCnet] 2/4 bag installation
Len
door with one that has a screen in it. Since I had it at the house I
figured why not....then it rained...........
I’ll let you know what it feels like as soon as I get that project done.
Cheers,
Len and Pat
78 Kingsley, The Beast II with dash lights that work
Fallbrook, CA
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
Len
roll, the ride is firmer, better response, all in all not a bad kit at all.
It took about 4 hours or so to do both sides. I
I'm still running 120 psi in the system, same as before.
Cheers,
Len and Pat
78 Kingsley, The Beast II with dash lights that work
Fallbrook, CA
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of Jim Bounds
Sent: Monday, November 30, 2009 4:16 PM
To: gmc...@temp.gmcnet.org
Jim Kanomata
Most of the ones with the Duel Bag are running 85-95psi.
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Len
Jim Kanomata
bag and the original are very similar.
The ride height is going to determine the pressure.
In this case the ride height must be higher than standard , otherwise
it would have been around 85-95 Max.
Ken Burton
jimk wrote on Sat, 05 December 2009 18:09
> We know from our installation and others that the pressure of the Duel
> bag and the original are very similar.
> The ride height is going to determine the pressure.
> In this case the ride height must be higher than standard , otherwise
> it would have been around 85-95 Max.
I think you guys are talking two different things. I'll bet Len is talking about the cutoff pressure in the tank and Jim you are talking about the pressure in the bags.
?????
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Larry
When moving slowly over a large bump the common setup as in the original design would presumably have an advantage as the wheels could "walk" over the bump. True?
_______________________________________________________________
True.
One of the shows GM used to do was to drive over 4x4's lay in front of the rv. The GMC would walk over them easily but the SOB would jump over them with the standard suspension. The crowds would get a kick of it.
Trying to decide which version to get.
Gary
________________________________________________________________
The all work well under NORMAL CONDITIONS. Focus on the NORMAL.
I think the first version was considered as a replacement to the OEM system, the purpose was to keep the coach up and operable. I don't beleive ( my thought ) they had any consideration for running on one bag, and that seems to be true of all but the last version as the middle support seems to bend when one bag is down.
The latest version has a "t" configuration of ( I think ) 3/8" metal so if one bag goes down, the metal will not bend and you can limp to a place to find a new bag.
So if all you are concerned with is replacing the OEM single bag system, any of them will work.
If you want the best and ability to MOVE THE COACH with one bag without flexing the metal support, the latests is the one.
I have the latest system, and I did have to work on a bag and the are reasonably easy to disassemble work on. I listened to the guys installing it and they said it was easier to work with. The other system had some bends and was difficult to maneuver to position for bolting.
all in all the latest is the greatest.
LarC ( Glad I did not waste money on the OEM bags after getting the 4 bagger installed )
--
Gatsbys' CRUISER :d
74 GLACIER X, 260
455/APC/4 bagg'r(ver3)
Remflex Manifold gaskets
_______________________________________________
Purchased 08-18-04
_
Len
same at the tank.
Len and Pat
78 Kingsley, The Beast II with dash lights that work
Fallbrook, CA
http://www.gmcmhphotos.com/photos/showgallery.php?cat=4375
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of Ken Burton
Sent: Monday, December 07, 2009 9:35 PM
To: gmc...@temp.gmcnet.org
Subject: Re: [GMCnet] 2/4 bag installation
Larry
If the manufacturer is not interested in improving his product to a more reliabble state, we'll do it! If it is said there has been seen no problems with the system to date, that pretty much answers that question. You hit the same brick wall I did, being in the business though I cannot just let it go-- and I won't!
_______________________________________________________________
Having the Current 4 bagg'r installed I have had nothing but confidence and no worries when going down the road. I was always concerned when the OEM bag system was still on the coach. Granted it was a fantastic new technology when new but times have changed and the need for something different had come up with this home run.
THE ONLY FAULT that I have, and it is certainly NOT inherrant of the bag system but of the coach suspension itself, is the fact that they did not incorporate a stop to prevent the wheels from hitting the wheel wells when the bags are down.
The bags system does everything else to a form of excellance but the crowning touch would be to put in a travel stop. This would not be needed for travel as the bag system can support for one bag but my 74 Glacier will rest on the wheel wells when the bags are down and if you need to move the coach, this will cause damage to the wells.
Since the old fix for a bag emerg replacement was a rod holding the support arms apart, a replacement for the failed bag, there would be little more concern for damage and if rubber were incorporated, like a motormount or such, even less concern for damage. It just needs a little give.
Otherwise, the 4 bagg'r is the way to go. Of the types available, the reinforced unit would be the choice.
LarC ( Thinking we could forget the ritual of blocks when storing the GMC if the wheels could not hit the wheel wells )
--
Gatsbys' CRUISER :d
74 GLACIER X, 260
455/APC/4 bagg'r(ver3)
Remflex Manifold gaskets
_______________________________________________
Purchased 08-18-04
_
Gary Casey
original or the aftermarket version, has a slight, but not significant performance advantage. The independent spring designs (aka 4-bag or Q-bag) have the advantage that it presumably can be run with one tire flat, although there are some that argue with that. I have no relevant experience. Other than that I don't see any intrinsic advantage of the independent system over either common spring design. The new systems have the advantage of easily-replaceable bags, but at a cost. I'd really like to know the spring rates of each of the alternatives, but I can't seem to come up with that number. Better yet, give me the ride frequency as that is more universal. Being a newcomer I don't know what is best, but from what I have heard a ride frequency somewhat higher than standard would be an improvement - but how much?
Gary
23 with original bags and plastic cones. Yikes.
________________________________
From: Larry <slawre...@yahoo.com>
To: gmc...@temp.gmcnet.org
Sent: Tue, December 8, 2009 8:49:09 AM
Subject: Re: [GMCnet] 2/4 bag installation
When moving slowly over a large bump the common setup as in the original design would presumably have an advantage as the wheels could "walk" over the bump. True?
Jim Kanomata
not as a new fenderliner was used.
With the Quadra Bag, you should never be in that situation as there
will always be one bag not damaged to keep it far enough up.
Driving over a 4" block of wood is not a problem with the Q Bag units.
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Randy
Is there any maintenance required on the hinge point in the dual bag system?
--
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
Rob Mueller
Is it possible to calculate what you want to know and if yes what
information would you need?
I have Lee Harrison's system on The Blue Streak here in Australia and could
provide information as to how it is constructed.
Let me know what you need to know.
I would think that Jim K would be able to provide what you'd like to know on
the Q-Bag.
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of Gary Casey
Sent: Wednesday, 9 December 2009 3:23 AM
To: gmc...@temp.gmcnet.org
Subject: Re: [GMCnet] 2/4 bag installation
I'd really like to know the spring rates of each of the alternatives, but I
can't seem to come up with that number. Better yet, give me the ride
frequency as that is more universal. Being a newcomer I don't know what is
best, but from what I have heard a ride frequency somewhat higher than
standard would be an improvement - but how much?
Gary
23 with original bags and plastic cones. Yikes.
_______________________________________________
Gary Casey
Probably the most universally-used measure is ride frequency, which is proportional to the square root of the mass divided by the spring rate. Air bags have a continuously-varying rate, so it must be specified at a standard position, like the design ride height. In the case of an air bag the rate is proportional to the pressure, which in turn is proportional to the weight, so that term goes away.
There's probably a few ways to arrive at the number, but here is probably the easiest: The effective diameter of the bag is required, and for the original bags I would guess that a measurement of the "high spot" diameter would be pretty close. In other words imagine laying a straightedge across the end and where the bag touches is the diameter. Can't be done because the cone is in the way, but I would think one could guess at it. Mine is on blocks right now, but it probably wouldn't make much difference. Then you need to know the volume at the normal ride height and that is a little harder. Again, with the original bags a good guess might be close enough. The manufacturer of the new bags should be able to provide the data, but again, a measured approximation might be good enough. Then the only thing required is the effective radius of actuation(pivot to the center of the bag) and the radius of the swing arm. With that information the ride
frequency can be calculate. The beauty of air suspension is that the ride frequency doesn't change with weight - the ride "quality" is the same light or heavy. Just the pressure in the bag changes. That was the big incentive for using airbags in the rear of some of the large front-wheel-drive cars (Eldo). Besides having the same right height the frequency was constant as weight was added. In our coaches the weight doesn't change much, so that isn't a consideration. I've lost track of who said what about which suspension design, but as I understand it there are 4 different set-ups: The orginal single-bag, the "dual bag" replacement, the "4-bag" and the "Q-bag." Each apparently uses different bag configurations, effective radius and probably internal volume. If I had the data I would like to calculate the difference. Might be enlightening.
Gary
________________________________
From: Rob Mueller <robmu...@iinet.net.au>
To: gmc...@temp.gmcnet.org
Sent: Tue, December 8, 2009 12:04:15 PM
Dan Gregg
Our coach had brand new bags when we bought it. After I got it home I saw where it had been dropped, on the passenger side, as that fender well was patched.1974 model. First trip out west I had Jim's guys replace the new single bags with the Quadra bag system. I have never worried again. I also saw George's, from NY,coach in Raine after he had popped a tire and a single bag. Tore the side of his coach out. I was converted right then and there. Teri and I headed to the Bay area shortly there after for the Quadra Bags.
Dan
towing the bug home from Topeka Graphics
--
Dan & Teri Gregg
///Halon Automatic Fire Extinguishers
Rob Mueller
Bug looks great! I disagree with one thing, however.
I think Teri's opinion counts too, er MORE! ;-)
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of Dan Gregg
Sent: Wednesday, 9 December 2009 10:39 AM
To: gmc...@temp.gmcnet.org
Subject: Re: [GMCnet] 2/4 bag installation
Dan towing the bug home from Topeka Graphics
--
Dan & Teri Gregg
_______________________________________________
Dave Mumert
I just posted some data on the original air bags. It is not complete but
may be of some help.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=31940
http://www.gmcmhphotos.com/photos/showphoto.php?photo=31941
Dave
> -----Original Message-----
> Subject: Re: [GMCnet] 2/4 bag installation
>
_______________________________________________
Larry
Is there any maintenance required on the hinge point in the dual bag system?
_________________________________________________________________
There are no additional moving parts.
You will have an addition air manifold with a supply valve and a valve for each bag and a psi guage, schroder valve.
if you put protection on the rubber bags, you have an additional one.
Thats about it.
LarC ( Thinking the 4 bagg'r is probably one of the best upgrades I ever did. )
--
Gatsbys' CRUISER :d
74 GLACIER X, 260
455/APC/4 bagg'r(ver3)
Remflex Manifold gaskets
_______________________________________________
Purchased 08-18-04
_
Rob Mueller
I've sent an email to Lee Harrison asking for the part number of the bags he
uses on his set up as that's what I have on The Blue Streak.
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist...@temp.gmcnet.org
[mailto:gmclist...@temp.gmcnet.org] On Behalf Of Dave Mumert
Sent: Wednesday, 9 December 2009 11:08 AM
To: gmc...@temp.gmcnet.org
Subject: Re: [GMCnet] 2/4 bag installation
Hi All
I just posted some data on the original air bags. It is not complete but
may be of some help.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=31940
http://www.gmcmhphotos.com/photos/showphoto.php?photo=31941
Dave
_______________________________________________
Jim Kanomata
The pivoting point has a grease nipple so that you can grease it at
the same time as the pins.
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Ken Burton
WD0AFQ wrote on Tue, 08 December 2009 17:38
> Our coach had brand new bags when we bought it. After I got it home I saw where it had been dropped, on the passenger side, as that fender well was patched.1974 model. First trip out west I had Jim's guys replace the new single bags with the Quadra bag system. I have never worried again. I also saw George's, from NY,coach in Raine after he had popped a tire and a single bag. Tore the side of his coach out. I was converted right then and there. Teri and I headed to the Bay area shortly there after for the Quadra Bags.
> Dan
> towing the bug home from Topeka Graphics
YoOu should stop at the Duracool store in in Leesbuurg. Indiana 15 just north of US 30
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Rob Mueller
I received the response below from Lee.
Here's a link to the data sheet for this air bag;
http://www.firestoneindustrial.com/pdfs/OE/OE_Data_Sheets/224.pdf
The picture below shows how they mount on the bogie arms.
http://www.leighharrisongmcmotorhomeupgrades.com/NewPage17.html
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: leighhar...@aol.com [mailto:leighhar...@aol.com]
Sent: Thursday, 10 December 2009 2:00 AM
To: robmu...@iinet.net.au
Subject: Re: Information Request
Rob,
The Firestone part # [224] W217600335. Our price is $125 ea. Our web site is
idencorpgmc.com.
LEIGH