Air bag suspension truth and facts...

[skypilot_1]

This whole thing was pretty lame days ago. But what the heck, more entertaining then all the pop up commercials here. Did bout 500 miles on I-30 today and didn't one tour bus or big rig that had statement..."Ride on iron leaf spring suspension" painted on side. I wonder why not...?

[slemnah]

Found this write up and agree with everything it states. I have been an ASE Master Tech for 40 years and have driven everything from the smallest car to the largest truck. I own a DP with air bag suspension and while it isn't perfect it blows the doors off of springs and shackles.

Three basic types of suspensions are used in Class A motorhomes. They are leaf/coil steel-springs, air bags, and torsion bars. Within each category there are various methods of positioning components that effect the weight capacity and handling characteristics. This FAQ will describe the basic differences between these suspensions. Before we start, it is interesting to note that no modern over-the-road bus chassis use spring suspensions. Most school buses use leaf spring suspensions. Most light and medium duty trucks use spring suspensions. After you read this article, you will understand why this is true.

LEAF/COIL SPRING suspensions are the least expensive and the hardest riding. Handling on the highway is significantly affected by crosswinds or the wind forces created when an 18 wheeler blows by the motorhome. The close mechanical coupling between the axles and the frame of the motorhome transmits noise, vibration, and side forces. Except for small rubber or plastic bushings, there is a steel to steel connection. The bumps in the road are transmitted directly into the chassis of the coach and neither sound nor vibration is dampened. To see the worst case in the ride characteristics of this type of suspension, find a way to take a ride in the rear seats of a school bus. Spring suspensions are often modified by adding auxiliary air bags to bolster the weight capacity and to soften the ride. After-market steering stabilizer and sway bars are frequently added to increase highway directional stability and reduce tipping. Spring suspensions have significant leaning when turning corners and very hard riding over bumpy roads. Leaf springs eventually sag and require added leafs to correct the ride height, especially from side to side. Because most roads are crowned to let rain water run off, driving many miles on a slant causes the passenger side to eventually sag. The older the motorhome the greater the chance for the necessity for this repair.

AIR BAG suspensions can be four air bags or eight airbags and significantly soften the ride characteristics. Air bag suspensions use automatic pressure regulators on side-to-side and front-to-rear to dynamically adjust the air pressure in each air bag to compensate for the tipping forces the coach is experiencing. Thus while turning a corner, the outside air bags are automatically inflated to compensate for the leaning of the coach. The vehicle thus goes through corners and through high side winds with far less tipping motion. Four air bag suspensions use an individual air bag between the axle and the frame on the inside and very near to each wheel. Solid axles are called "live axles" and are one piece and ridged. Both Spartan and Freightliner now offer front independent suspensions systems that use an air bag inside an A-frame supporting each front wheel. This independence allows each front tire to follow the terrain that it faces and thus results in a smoother and more stable ride than a live axle suspension. Independent front suspensions have been used in automobiles since the 1940's but have only recently found their way into motorhomes and some passenger buses. Eight air bag suspensions have an axle carriage that allows two airbags to be placed above and to the front and rear of each wheel. The result is much greater side-to-side support and less tipping than a four-bag system. Since the ride height is automatically and dynamically adjusted, there is never any sagging. Airbags can develop leaks or blow out, but they are relatively inexpensive to replace. Airbag suspensions are much more compliant to side-wind conditions and the resulting sway. The softness can sometimes cause porpoise(ing) like action while driving on undulating roadways. This is normally dampened properly by shock absorbers. Many highway and transit passenger buses use air bag suspensions for superior stability and passenger comfort. When parked, it is possible to dump the air out of the airbags and lower the coach for easier egress. Some more sophisticated systems can also raise and lower the ride height while traveling down the road. The driver can lower the whole coach while traveling on a flat interstate or raise it up to negotiate a steep driveway. The air in the bags significantly reduces the noise and vibration transmitted from road surfaces.

TORSION BAR suspensions use a steel bar in a sleeve connected to a lever arm to provide the up and down action. Newer torsion bars are encased in hard rubber inside the sleeve to further buffer the road noise and vibration between the axle and the chassis. Eagle passenger buses made this suspension famous and many entertainers will only use Eagle buses for touring because of their ride characteristics. Torsion bar suspensions are less effected by porpoise(ing) and have excellent resistance to tipping. Foretravel and Safari are the major motorhome builders that use or have used this suspension system. Ride-height is adjusted by loosening the lever arm and twisting the bar with special tools and then tightening the arm. Adjustment is limited and when the bar ages, replacement is relatively expensive. Torsion bar suspensions are used on some travel providing lower ride levels and thus a lower center of gravity. Torsion bars are used in some automobiles and light duty trucks.

[skypilot_1]

You was posted this same thing @ #102 today as well. We get it.

[cbilodeau]

Originally Posted by skypilot_1

You was posted this same thing @ #102 today as well. We get it.

I think is shaken with what the expert LVRVLUVR has explained us this week.

I just went for a walk with my wife and explained her what the expert LVRVLUVR says. She was always saying before today that one day we should buy a DP. But today she said: it means we could not have the flexibility we have. It is not for us.

I think this thread will be very useful for many. We are lucky to have such an expert who had so many different kind of motorhomes and cars.

[jondrew55]

I notice you're still around @ #115

Originally Posted by skypilot_1

You was posted this same thing @ #102 today as well. We get it.

[slemnah]

Originally Posted by skypilot_1

You was posted this same thing @ #102 today as well. We get it.

I didn't repost it. Not sure why it came up again.

[slemnah]

Originally Posted by cbilodeau

I think is shaken with what the expert LVRVLUVR has explained us this week.

I just went for a walk with my wife and explained her what the expert LVRVLUVR says. She was always saying before today that one day we should buy a DP. But today she said: it means we could not have the flexibility we have. It is not for us.

I think this thread will be very useful for many. We are lucky to have such an expert who had so many different kind of motorhomes and cars.

If you made the decision not to buy a DP based upon this discussion then I would ask you to reconsider. A friend of mine bought his first motorhome and it was a gas model. He spent a fortune trying to get it to ride and track correctly. He just upgraded to a DP and loves it. You might go and drive one and then decide for yourself.

[cbilodeau]

Originally Posted by slemnah

If you made the decision not to buy a DP based upon this discussion then I would ask you to reconsider. A friend of mine bought his first motorhome and it was a gas model. He spent a fortune trying to get it to ride and track correctly. He just upgraded to a DP and loves it. You might go and drive one and then decide for yourself.

I am sorry if you took bad decisions. I will not do the same. A/C running all day long in Yellowstone park, Zion Park, Grand Canyon Park? Have to travel the 5 kids in a car because the DP can not stop at every sightseeing. I have seen all those DP that did not move all day long. I need mobility, LP, solar panels, opening windows, nice view. I don't want small little windows inserted in a container and a suspension that is limited to 10% of the road where I need to go.

I was in the Florida Keys in december. My friend could not move his DP to the beaches we went. At 45 years old, he stayed in a retired communitiy for 30 days.

[slemnah]

Originally Posted by cbilodeau

I am sorry if you took bad decisions. I will not do the same. A/C running all day long in Yellowstone park, Zion Park, Grand Canyon Park? Have to travel the 5 kids in a car because the DP can not stop at every sightseeing. I have seen all those DP that did not move all day long. I need mobility, LP, solar panels, opening windows, nice view. I don't want small little windows inserted in a container and a suspension that is limited to 10% of the road where I need to go.

I was in the Florida Keys in december. My friend could not move his DP to the beaches we went. At 45 years old, he stayed in a retired communitiy for 30 days.

I am sorry, not sure what your post has to do with the original topic of leaf spring suspensions vs air suspensions. I happen to like parking mine in a nice Rv park and driving my vehicle to where I am going. I only have to set it up once and take it down once. I that isn't the lifestyle that you want or need then you buy what fits your needs. Also I don't understand your first sentence. Please explain it to me. What bad decisions did I take??

[cbilodeau]

Originally Posted by slemnah

....

I that isn't the

....

Please explain to me what "I that" means.

Originally Posted by slemnah

...

the lifestyle that you want or need then you buy what fits your needs.

Are you sure members that read this thread can really buy something that fits their needs? Because you said previously: "air bag suspension and while it isn't perfect it blows the doors off of springs and shackles". So if someone wants to buy a motorhome to go on non paved road like I do, your air bag suspension will be superior? Are you serious?

If you were rational and not only trying to justified your DP then you would have said just like the RV expert LUVLURV: my air bag suspension while it isn't perfect, will be superior on a big nice clean highway but not on every road.

If you let the discussion continue about the technical specs then we will have the chance to learn a lot like we did in the first posts. But if you come here simply to say: it is better no matter what, no matter when, no matter how then you are simply trying to derail a thread because you want to protect your DP decision like some would do for a religion.

Also to say it will blow the doors is a bit emotional. I drove my gasser from Montreal to western USA and the kids play monopoly, they eat, they play PS3 and PS4, they watch movies. Nobody womit, nobody is sick, nobody has to stop. Some sleep on the bed while I am on the road. Emotional = "will blow doors". Rational = "is 30% more confortable on a nice clean highway". With rational argument, buyers take better decisions. With emotional arguments we take decisions like you did.

Please think about it and come back in the discussion with rational arguments. I will read you.

[cbilodeau]

Originally Posted by Scatterbrain

The only person who believes LVRVLVR is an expert, aside from himself, is you.

So you talk in the name of the whole community since you know I am the only one? They voted and they asked you to say that? You are way to much emotional to come discuss on a technical forum. LVRVLUVR has had many DP and gasser, he had garages, created suspensions systems, dumb buggy, modified many motorhomes, etc. If this is not an expert then who is?

Originally Posted by Scatterbrain

The only person who believes LVRVLVR is an expert, aside from himself, is you.

Originally Posted by Scatterbrain

....

However, do you want to clean the salt out of your chassis? Do you want to risk sliding off the road, or having a large truck slide into you? Back home there were two types of weather that would make us cringe, cold winter nights after wet days and stormy fall days.

I live in Canada. Snow can start in october and finish in april. Are you saying that we don't have buses, trucks during those months? Are you rational? Check on youtube if you don't beleive me. School bus are on the road all winter long with no accidents.

I took my motorhome in the snow during the winter. Although Ford built a F53 that goes perfectly in the snow, the builder did not do a good job. But if I spend more money, even 500k, it will still not be snow proof? Is this a joke?

[NC25T]

Originally Posted by cbilodeau

I am sorry if you took bad decisions. I will not do the same. A/C running all day long in Yellowstone park, Zion Park, Grand Canyon Park? Have to travel the 5 kids in a car because the DP can not stop at every sightseeing. I have seen all those DP that did not move all day long. I need mobility, LP, solar panels, opening windows, nice view. I don't want small little windows inserted in a container and a suspension that is limited to 10% of the road where I need to go.

I was in the Florida Keys in december. My friend could not move his DP to the beaches we went. At 45 years old, he stayed in a retired communitiy for 30 days.

Where in the keys are beaches you can take your RV?

It's not really DP vs gas, it's just a matter of length. If a 32ft gas coach can fit somewhere so can a 32ft DP. If the owner decides to buy a 45ft coach, the owner is to blame for buying to large of a coach for the places they want to go, not the type of fuel or where the engine is.

According to your theory since I wasn't able to fit into a few camping areas we wanted to stay at in my class A gas and my now X inlaws could fit there in their class C, according to your theory class C is better?

[slemnah]

Originally Posted by cbilodeau

Please explain to me what "I that" means.


"If that".


Are you sure members that read this thread can really buy something that fits their needs? Because you said previously: "air bag suspension and while it isn't perfect it blows the doors off of springs and shackles". So if someone wants to buy a motorhome to go on non paved road like I do, your air bag suspension will be superior? Are you serious?

If you were rational and not only trying to justified your DP then you would have said just like the RV expert LUVLURV: my air bag suspension while it isn't perfect, will be superior on a big nice clean highway but not on every road.

If you let the discussion continue about the technical specs then we will have the chance to learn a lot like we did in the first posts. But if you come here simply to say: it is better no matter what, no matter when, no matter how then you are simply trying to derail a thread because you want to protect your DP decision like some would do for a religion.

Also to say it will blow the doors is a bit emotional. I drove my gasser from Montreal to western USA and the kids play monopoly, they eat, they play PS3 and PS4, they watch movies. Nobody womit, nobody is sick, nobody has to stop. Some sleep on the bed while I am on the road. Emotional = "will blow doors". Rational = "is 30% more confortable on a nice clean highway". With rational argument, buyers take better decisions. With emotional arguments we take decisions like you did.

Please think about it and come back in the discussion with rational arguments. I will read you.

I have had the pleasure of driving and repairing old tractor trucks with leaf spring suspensions and they will rattle your teeth. My friend just purchased a 1ton ford pickup with leaf springs and I couldn't even talk without my voice breaking because of the rough ride even on smooth roads. Adding air bags fixed a lot of that problem, go figure! Maybe you didn't read my qualification but I have been in the automotive and truck business for 40 years, I think that gives me he right to make certain assumptions..... What's your experience? If you want to take yours off road then by all means do so. Many people with DP's don't go off road. The start of the article simply stated that in LVRLVR's opinion air suspensions are not as good as leaf springs and I disagree with that as is my right on this forum. You can believe whatever you like, you can purchase whatever you like but don't insult me. And yes in my opinion, because that's what we get to write about here, is that it blows the doors off of leaf springs. I don't intend to drive on the beach or take my motor home out in the boonies. I like the comfort of my S Series chassis without its 10 airbags and 525hp engine. And please, don't read me nor insult me anymore with your rapier wit. I am done with you! What a shame I can't really tell you what I think!

[cbilodeau]

Originally Posted by skypilot_1

This whole thing was pretty lame days ago. But what the heck, more entertaining then all the pop up commercials here. Did bout 500 miles on I-30 today and didn't one tour bus or big rig that had statement..."Ride on iron leaf spring suspension" painted on side. I wonder why not...?

Normally we should not answer such an easy question. I don't know if you are serious or if this is because you own a DP and want to justify it. Anyway I will answer you.

A train has a limited number of destinations. So the road is predictable.

An inter-city bus has a limited number of very nice highway road that are predictable. This is why they put on them the cheapest suspension system just like the expert LVRVLUVR has explained us in his first posts.

A delivery truck, an ambulance, a gasser motorhome has a much more possibility of destinations so they need leaf spring for non paved road, under construction roads, parks, etc.

Read the first posts of the expert LVRVLUVR, he did explained all that. He has had many RV, he developed suspensions, had garages, etc. Just listen. Put your emotions on the side and you will understand.