Air bag suspension truth and facts...

[LVRVLUVR]

Originally Posted by NC25T

If I recall you purchased a Jeep Wrangler not to long ago, you do realize that has solid front and rear axels... Model T tech at its finest... Have you seen a model T on one of those ramos where they test suspension travel? It's crazy good.... Almost comical

I know you mentioned you had a DP and went back to gas, which DP did you have? Did you try a few or only one DP?

lol.....not quite true... I paid for and it's my wifes car..I never have liked jeeps had a few through the years... we have no need for a jeep... we have 2 RZR 1000's that cost me over 50k..another 12k for a 22' triple axel trailer to get them to where we wanna go riding... some time the dunes.... some time the trails in Utah and parker..

I was perfect fine with my little hhr.. all set up to tow, and if I wanted jump in and run it to the house in havasu..jeep is not a good freeway car imho.. and not to offend jeep owner,... just one of my opinions... my wife has a brand new convertible BMW... it sits and she drives the jeep...

she didn't think the hhr was cool at all and talked me in to trading it in on the jeep... her idea was it would be a cool toad...

as for the DP's I think to date I have had 16... for 40' down to 33' bounders, discovery's expiditions, journeys and the last was an excursion

probley one of my all time favorite one was the 34' that came with the 300 cat... took it to cat and they uped it to 340 hp for 1400 bucks..i used to put about 34k miles in a years and get a new one..once the boys move out I went to the smallest coach I could get... I used to go back in forth from gas
to deisel .. realyy like the work horse chassis and was bummed when the went to straight axel... most always got the 32'r in gas

[LVRVLUVR]

I really really really miss this coach...

https://www.youtube.com/watch?v=yflrl-oK01E

[LVRVLUVR]

Originally Posted by ahicks

Let's not forget there are a few different airbags w/internal and external design differences that engineers can select from (4 bags or however many). All air bags are not created equally. Proper selection done there is similar to getting a sprung coach right. There's no universal "right" way to do it. You start with what works on paper, but then you need to get your hands dirty - and some companies just don't seem to get that. What works on paper goes into production there - leading to mistakes like the P30 airbag situation.

I hope those left on the fence here will drive several coaches - so you can
be the judge.

I think with your coach the size makes a difference where as the shorter coach is at a disadvantage

the suspension is just too choppy on the smaller ones

[rvadventure]

No truer statement than this for the entire thread! Sweetbrier seems to have the facts! Regards

[LVRVLUVR]

question for those in the know//

who make the alpine chassis...alpine?? they made a 34 with a 400 cuminin

they seem to have a timeless design on the coach..

If you have specific technical questions, please DO NOT email the webmaster,
we recommend you post them on iRV2

[cbilodeau]

Conclusions so far:

1 - Don't pay for a DP if you are only looking for a better suspension. People have confirmed here that many DP model and sizes don't have a good suspension.

2 - A DP with air suspension will be worst than a gasser on a bad road and one of the top IRV2 expert (LVRVLUVR) also explained us why.

3 - Shocks and leaf springs on the gassers are not bad and are the best choice when you travel a lot on roads where DP don't want to go.

4 - Before we buy a DP we must understand that we will be limited on the kind of roads and places where we can go. Travelling with five kids onboard stopping at each nice spot and each non-paved road in a national park is no more possible unless you park the DP and use the car all day long.

5 - In campground I let DP owners explains me how much a DP is better in everything but now it is possible since june 1st 2016 to have rational technical discussions with an expert here on IRV2.

Looking forward for real rational discussion about the other greats lies I hear all year round in campground:

1 - Why an electrical Fridge on a DP is better than my LP/Electric Fridge that can run 3 month on a single LP tank without electricity.
2- Why in a house a gas stove is better than an electric one but for a typical DP owner an electric stove is better on a coach.
3 - Why a house with many opening windows is better but a DP with only a few and non-opening windows is better.
4 - Why is it less stress to go on a trip with a DP for which a simple repair could cost you 3000$ while for a gasser you could pick a part on a pickup truck in the USA and it could fit.
5 - How do you cook for the childrens on an DP electric stove when you are not allowed to run the generator in a park?
6 - Why my friend paid in 2015, 600$ to have a repair on a DP wipers arm, 600$ for a generator starter problem, 600$ on his hydraulic jack system that is still not working and 4500$ for his 6 tires?

So many subjects...

[crah]

Originally Posted by LVRVLUVR

question for those in the know//

who make the alpine chassis...alpine?? they made a 34 with a 400 cuminin

they seem to have a timeless design on the coach..

If you have specific technical questions, please DO NOT email the webmaster,
we recommend you post them on iRV2

Alpine made their own Chassis called a Peak Chassis. You seem to be all over the place on your comments. I can't quite figure out what you are trying to relay. You seem like you have good intentions but maybe you need to word things a little differently.

As for your knowledge on diesel pusher air bag suspension, you are way off base. Just like RV'S not all air suspension are equal. There are many 4 bag suspension that are great. Maybe you should read up on things like active air. There are many different ride height valves and systems. Look up HWH active air or Valid, or Hendrickson, or Hadley. They all make many versions of ride height valves. This type of air bag suspension is nothing like the aftermarket firestone ride rite type air bags many people are familiar with.

I'm no expert, but have played with several ride height valves and understand some work better than others.

Not sure what you are trying to relay.

[LVRVLUVR]

heres another fact for you all from the dozen or so freightliner chassis that I have owned... ride height is cridical on the freightliner...
as it has been discussed loosely in this thread , you cannot go out and change the ride height on the freightliner... although there is an adjustment...the adjustment is cridical to the chassis...

changing ride height to get a smoother ride is not obtainable..

there are specific measurement to get proper pinion angle on the rear end..

working with freighliner I used to do a mod to the front levers to help with the stiff front suspension(34'rs) because I never loaded the coach to the weight it was designed and got less then what was available in suspension....

never ever ever mess with the levers....bad things can happen, same as driving
the coach with them out of adjustment...
working with measurement from freightliner tech, I was able to do a little adjusting to the front only....
hope this is clear and everyone understands....it is also wise to have the
lever measurement checked if you have an older coach and also have the whole air ride system inspected...

[LVRVLUVR]

Originally Posted by crah

Alpine made their own Chassis called a Peak Chassis. You seem to be all over the place on your comments. I can't quite figure out what you are trying to relay. You seem like you have good intentions but maybe you need to word things a little differently.

As for your knowledge on diesel pusher air bag suspension, you are way off base. Just like RV'S not all air suspension are equal. There are many 4 bag suspension that are great. Maybe you should read up on things like active air. There are many different ride height valves and systems. Look up HWH active air or Valid, or Hendrickson, or Hadley. They all make many versions of ride height valves. This type of air bag suspension is nothing like the aftermarket firestone ride rite type air bags many people are familiar with.

I'm no expert, but have played with several ride height valves and understand some work better than others.

Not sure what you are trying to relay.

I think you are an expert and I think also that you are a polite person that takes alittle time to ask a question rather than flame someone

now where did I say all the truth and facts would come from me...

i'm an expert.... I don't know it all, and I can clearly see that there is much to be learned from your post...

so here we go.... i'm on a quest for a 32-34 ft coach....I want a 400hp cummins motor

although I would not eliminate freightliner... was hoping for something better..

the alpine has realy caught my eye,... and I really like that they put an isolater between the frame and coach..also????? whats the good and bad with their chassis.. they only have 4 bags.... but they clain to be superior

they do have active air

my other want coach is the country coach...both seem to be up there is quality build and both seem to have a quality timeless design..

for me... ford is not really an option for a bigger coach..i want more power already and I have a 26'r

I don't want res fridge or having to deal with def... and all the newer coaches in my want size have that plus little motors, transmissions, and little tires

so if I may,... what good/bad would you have to say about my quest..

[LVRVLUVR]

Originally Posted by cbilodeau

Conclusions so far:

1 - Don't pay for a DP if you are only looking for a better suspension. People have confirmed here that many DP model and sizes don't have a good suspension.

2 - A DP with air suspension will be worst than a gasser on a bad road and one of the top IRV2 expert (LVRVLUVR) also explained us why.

3 - Shocks and leaf springs on the gassers are not bad and are the best choice when you travel a lot on roads where DP don't want to go.

4 - Before we buy a DP we must understand that we will be limited on the kind of roads and places where we can go. Travelling with five kids onboard stopping at each nice spot and each non-paved road in a national park is no more possible unless you park the DP and use the car all day long.

5 - In campground I let DP owners explains me how much a DP is better in everything but now it is possible since june 1st 2016 to have rational technical discussions with an expert here on IRV2.

Looking forward for real rational discussion about the other greats lies I hear all year round in campground:

1 - Why an electrical Fridge on a DP is better than my LP/Electric Fridge that can run 3 month on a single LP tank without electricity.
2- Why in a house a gas stove is better than an electric one but for a typical DP owner an electric stove is better on a coach.
3 - Why a house with many opening windows is better but a DP with only a few and non-opening windows is better.
4 - Why is it less stress to go on a trip with a DP for which a simple repair could cost you 3000$ while for a gasser you could pick a part on a pickup truck in the USA and it could fit.
5 - How do you cook for the childrens on an DP electric stove when you are not allowed to run the generator in a park?
6 - Why my friend paid in 2015, 600$ to have a repair on a DP wipers arm, 600$ for a generator starter problem, 600$ on his hydraulic jack system that is still not working and 4500$ for his 6 tires?

So many subjects...

heres the problem with propane for full timers..what do you do when you run out of propane.... have you ever seen what full timers do to their space... they decorate the coach like a Christmas tree... and put out more lard furnishings than home depot... so now what...pack up and go get propane..
I know there are some places where the truck come by like the ice cream man... but what if you miss him..

I 'm with you on the propane and don't welcome the change ... but I see it more and more on the gas coaches also

gas is gonna make a big come back with snow birds... they only drive twice a year and flock together like sheep going down the road 50mph..

[crah]

Originally Posted by LVRVLUVR

I think you are an expert and I think also that you are a polite person that takes alittle time to ask a question rather than flame someone

now where did I say all the truth and facts would come from me...

i'm an expert.... I don't know it all, and I can clearly see that there is much to be learned from your post...

so here we go.... i'm on a quest for a 32-34 ft coach....I want a 400hp cummins motor

although I would not eliminate freightliner... was hoping for something better..

the alpine has realy caught my eye,... and I really like that they put an isolater between the frame and coach..also????? whats the good and bad with their chassis.. they only have 4 bags.... but they clain to be superior

they do have active air

my other want coach is the country coach...both seem to be up there is quality build and both seem to have a quality timeless design..

for me... ford is not really an option for a bigger coach..i want more power already and I have a 26'r

I don't want res fridge or having to deal with def... and all the newer coaches in my want size have that plus little motors, transmissions, and little tires

so if I may,... what good/bad would you have to say about my quest..

For a 34 ft coach with 400 hp diesel pre def, besides country coach, Foretravel made a 34 ft version.They had the Allison transmission retarder which I would love to have. Also 8 air bags chassis that they made in house. Choices would be pretty limited for 400 hp 34ft.

Your posts are a little hard to understand. Some seem sarcastic, and some seem sincere. Your typing is nothing like your YouTube videos. You seem alright on the videos, but your typing is over the top.

[Sweetbriar]

Originally Posted by LVRVLUVR

heres another fact for you all from the dozen or so freightliner chassis that I have owned... ride height is cridical on the freightliner...
as it has been discussed loosely in this thread , you cannot go out and change the ride height on the freightliner... although there is an adjustment...the adjustment is cridical to the chassis...

changing ride height to get a smoother ride is not obtainable..

there are specific measurement to get proper pinion angle on the rear end..

working with freighliner I used to do a mod to the front levers to help with the stiff front suspension(34'rs) because I never loaded the coach to the weight it was designed and got less then what was available in suspension....

never ever ever mess with the levers....bad things can happen, same as driving
the coach with them out of adjustment...
working with measurement from freightliner tech, I was able to do a little adjusting to the front only....
hope this is clear and everyone understands....it is also wise to have the
lever measurement checked if you have an older coach and also have the whole air ride system inspected...

Clear, direct and accurate posting. Spot on!

Ride height and the associated suspension travel ranges is a compromise of many factors. Move it to far in either direction and bad, expensive things will happen. Checking height doesn't mean grabbing a tape measuring from the kitchen junk drawer and measuring at some point along the frame to the ground. You have to know where on the coach to take the measurement and what the allowable deviation from the designed standard is.

[Sweetbriar]

Originally Posted by cbilodeau

The text says that it does not respond to short changes. But LVRVLUVR talks about a whole bad road. He is not talking about a single bump on a good road. The text says that the system will adjust dynamically to such a road just like LVRVLUVR said.

You should ask questions to this expert if you want to understand fully these system.

Each bump, even with a long stretch of bad road is an individual sort duration event. A tire hits a bump, suspension compresses, tire returns to the road surface, suspension expands. Wash, rinse repeat. Each is an individual short duration dynamic event lasting less than a second. A guest of wind is a short duration dynamic event and will not cause a change. Hard braking is a short duration dynamic event and will not cause a change. A long stretch of high road crown will cause a change, a long sweeping turn that causes the coach to sway will cause a change, loading up for an outing will, dumping waste tanks will but 30 miles of pot holes or wash board road will not.

If the system did respond to these changes and release a given volume of air when a tire dips into a pot hole as soon as the tire hit the far side of the hole and returned to the normal road surface it would add air to maintain the correct ride height. On a wash board road it would do the same constantly correcting by adding or releasing. The point is the valves will not build up pressure on poor roads causing a harsh ride as the OP stated.

Something else to consider. The air used for the suspension is the same air need for braking. If the suspension was constantly adding and releasing air AND the compressor/storage tanks could not keep up with the demand the brakes will slowly apply as the pressure required to hold the brakes off is lost. Its the fail safe feature of air brakes and why you see lots of trailer skid marks angling off to the side of a road. They lost air for some reason to the trailer and the brakes on the trailer locked.

[Gdawgs]

Originally Posted by LVRVLUVR

here's why it doesn't work...

on a motorhome..a chassis that is designed for air bags has very minimal wheel travel... and a lot of weight....
the way it works is there is a ride height lever that when more weight is added .. it just adds more air... again....making the suspension stiffer..

the problem here is that when you come upon a bad road...washboard as it's called... the bumps cause the suspension to stiffen, because of the automatic
air being pumped in. and the suspenson travel hitting the lever... the suspension packs and you have none.....so what DP guys do...let air out of the tires to have suspension when they hit those roads...

and there is no fix as of to days tech.

my idea is to have a driver over ride switch that allows the driver to react when the auto system fails...

that way you can control the air pressure...

I have the RoadMaster chassis with 10 outward mounted air bags. These bags are mounted close to the wheels where springs can not be mounted and are smaller for quicker air adjustment. This gives greater stability similar to standing with your feet together then spreading your feet apart. The system is active when your on the road and adjust as needed to keep the coach level and stable in curves, springs can not. The system has a damping effect in that it doesn't react quickly but over 20 seconds or so. In that way it's not constantly adjusting to road conditions. I like the protections from the leaning of the coach, load weight adjustment and the reduced porpoising on heavy stops. The best part is the ability to level the coach with the bags on surfaces that you would not want your jacks on, sand, hot asphalt etc. and I have full control via a key pad to raise or lower front/rear or any corner with the Valid System.