Air bags on trailer

[rockcrawler31]

Ok. so i was bored at work and flicking through wheeling magazines looking for ideas for when i build a camper trailer. I saw an ad for full airbag suspension in 4wd's and i got to thinking.....

Is there any reason why an airbag couldn't be used in the place of coil springs in a camper trailer? I was already going to use coils and links so that i have some parts changeability with my cruiser towing it.

I already have the issue of a trailer that is too low and sits hitch high when being towed by my cruiser, you could just adjust the air in the airbag to suit the height of the towing vehicle. (I run two sets of coils in the cruiser - one for touring and one for playing). It also means you could adjust the air pressure for differing levels of load. You could lower the trailer down when settingup camping or trying to get my bike into the back.

The trailer is going to have a removable camping module so it will spend a lot of it's life as a 8x5 trailer hauling stuff around.

What are your thoughts?

I realise there is an issue with punctures, but a shield could be made up. Also on long trips most people carry spare springs for their CT's. A spare deflated airbag is smaller and lighter than a spare Leaf or coil spring.

[chimpboy]

I have to admit that we use the raise/lower capabilities of the range rover EAS all the time. The height difference is enough to make getting in and out MUCH easier for Ana (who is pregnant) and also for the dog (jumping into the back, he is in the car a lot).

It's amazing how much easier a few inches of variable height can make things. So, I can see how it could be useful on a camper trailer.

Having said all that, you would need to factor in:

- it would cost a lot more to set up than coils
- it has more components and more complexity - not just air springs but a compressor, a tank, valves, and a control system. (on the other hand the compressor and tank are useful for heaps of other things too)
- air bags would probably give a harsher ride than coils

Just some thoughts.

[Tiny]

I have to admit that we use the raise/lower capabilities of the range rover EAS all the time. The height difference is enough to make getting in and out MUCH easier for Ana (who is pregnant) and also for the dog (jumping into the back, he is in the car a lot).

It's amazing how much easier a few inches of variable height can make things. So, I can see how it could be useful on a camper trailer.

Having said all that, you would need to factor in:

- it would cost a lot more to set up than coils
- it has more components and more complexity - not just air springs but a compressor, a tank, valves, and a control system. (on the other hand the compressor and tank are useful for heaps of other things too)
- air bags would probably give a harsher ride than coils

Just some thoughts.

agree, although I am not sure they would be pareticularily harsher and the ride provided the trailer is built properly is not something you need to worry about in terms if ride. complexity wise, apart from the tanks / valves the actual suspension set up with links and mounts etc is no different

[-Scott-]

As the chimp pointed out, air is more complicated than coils - but I'm sure you'll cope.

As I understand it, the effective spring rate of an air bag can be altered by changing the centre bit (piston? mandrel? what's it called?).

I suspect that, with the right shape, you could achieve a higher spring rate when riding low (for load carrying around town) and a lower spring rate when riding high, for a softer, more supple suspension offroad.

But I have done zero research, so I'm probably very wrong.

[Tiny]

But I have done zero research, so I'm probably very wrong.

I love OL

[ludacris]

Is very expensive. If cost is not an issue great idea. Also more expensive to up keep. I would stick with coils and just get an adjustable tow bar hitch.

LudaCris

[chimpboy]

I suspect that, with the right shape, you could achieve a higher spring rate when riding low (for load carrying around town) and a lower spring rate when riding high, for a softer, more supple suspension offroad.

That is exactly how my aftermarket air springs are designed in the RR.

[pongo]

would actually be a great idea for a boat trailer, It would allow bigger tyres and then could dump the air to lower it 6 inches to help get it into the water.

Intresting. Cant see it costing a whole lot more. depends on what your willing to spend. Raid a truck wreackers and plenty of parts may be there for the picking cheap

[rockcrawler31]

Is very expensive. If cost is not an issue great idea. Also more expensive to up keep. I would stick with coils and just get an adjustable tow bar hitch.

LudaCris

Can't adjust the tow bar hitch. it's a pintle hook fitted up to the chassis.

What's with the upkeep? i would have thought that they would have a reasonable life span.?

but yeah, they look like costing a little more than coils. Although, i imagine i would need to be getting custom coils and probably two sets so that would offset the cost. I was just going to have a air reservoir on the trailer and run a quick connect line to the car and use the car's air supply.

The ability to adjust for differing loads height is really quite attractive.

Besides i could make it into a fooly sik lowrider with the jumping suspension

[muckute]

Another advantage of airbags in a camper is for leveling on uneven ground when setting up camp

[SteelArt]

mmm airbags are a good idea, don't see any issues and I wouldn't bother with all that compressor stuff, tanks etc etc.

You simply plumb them to a valve on the bumper and fill them up at the servo / home / car compressor etc, they are small volume anyway so it can be done with a hand pump if you want.

You also need to decide if you want them balanced or single. In a trailer I would go single so there are no issues with excessive roll.

As for cost last set I bought for an 80 series where around $250 each with valve kit so $500 a pr give or take a few dollars (www.airbagman.com.au)

[-Scott-]

mmm airbags are a good idea, don't see any issues and I wouldn't bother with all that compressor stuff, tanks etc etc.

You simply plumb them to a valve on the bumper and fill them up at the servo / home / car compressor etc, they are small volume anyway so it can be done with a hand pump if you want.

A potential compromise may be on board tank, filled from servo - then use the tank to make minor adjustments as required.

You also need to decide if you want them balanced or single. In a trailer I would go single so there are no issues with excessive roll.

With a few extra pneumatic switches you could have the best of both worlds - join the two to equalise pressures, then isolate for on-road roll stiffness. Open the connection for off-road articulation (or to encourage rolling on a side slope. ) With individual dump valves, you could isolate, and dump one to level the trailer.

If you wanted to get really fancy, you could use solenoids, and do it all from the cab. But that sounds like extra complication for little benefit.

[rockcrawler31]

mmm airbags are a good idea, don't see any issues and I wouldn't bother with all that compressor stuff, tanks etc etc.

You simply plumb them to a valve on the bumper and fill them up at the servo / home / car compressor etc, they are small volume anyway so it can be done with a hand pump if you want.

A potential compromise may be on board tank, filled from servo - then use the tank to make minor adjustments as required.

You also need to decide if you want them balanced or single. In a trailer I would go single so there are no issues with excessive roll.

In my case i would keep it simple. no levelling or solenoids, just an air tank plumbed into my cars air system, and individual fill points for the bags set manually.

With a few extra pneumatic switches you could have the best of both worlds - join the two to equalise pressures, then isolate for on-road roll stiffness. Open the connection for off-road articulation (or to encourage rolling on a side slope. ) With individual dump valves, you could isolate, and dump one to level the trailer.

If you wanted to get really fancy, you could use solenoids, and do it all from the cab. But that sounds like extra complication for little benefit.

[JWB]

Have a look at the 2nd page for some photos

http://myswag.org/forum/index.php?topic=2996.15

[chimpboy]

mmm airbags are a good idea, don't see any issues and I wouldn't bother with all that compressor stuff, tanks etc etc.

You simply plumb them to a valve on the bumper and fill them up at the servo / home / car compressor etc, they are small volume anyway so it can be done with a hand pump if you want.

A potential compromise may be on board tank, filled from servo - then use the tank to make minor adjustments as required.

You also need to decide if you want them balanced or single. In a trailer I would go single so there are no issues with excessive roll.

With a few extra pneumatic switches you could have the best of both worlds - join the two to equalise pressures, then isolate for on-road roll stiffness. Open the connection for off-road articulation (or to encourage rolling on a side slope. ) With individual dump valves, you could isolate, and dump one to level the trailer.

If you wanted to get really fancy, you could use solenoids, and do it all from the cab. But that sounds like extra complication for little benefit.

The trick (imho) would be to put all the valves neatly together in a valve block, manifold kind of arrangement. Use 6mm tubing to run everything where it needs to go. This set-up would make it a neat job to operate it electrically from the cabin.

It's not even that many valves if you put them in a manifold.

1 for upness (ie open to air tank)
1 for downness (ie open to atmosphere)
1 for left spring
1 for right spring

open left and right springs at the same time for the crosslink action.

In my case i would keep it simple. no levelling or solenoids, just an air tank plumbed into my cars air system, and individual fill points for the bags set manually.

I would still say you want a little valve block really, it is going to be simpler if you have a single air distribution point. And once you one it is really hard NOT to have the corss link/levelling option, if you open both springs' valves then they join up.

[-Scott-]

The valves don't need to be electrically actuated. Pneumatic switches are simple & easy.

[phat-customs]

The valves don't need to be electrically actuated. Pneumatic switches are simple & easy.

realistically they could be as simple as a ball-valve... albieit a little agricultural. Easy to equalise etc.

I reckon this setup would be TITS on a car trailer and have hassled many people in the past about building such a system.

All the air lines from ur tank/valves to the bags could be run in steel line/or copper, no real need for rubber/plastic lines so thats not going to be a concern.

I think go for it!

[nottie]

Another advantage of airbags in a camper is for leveling on uneven ground when setting up camp

Problem with this is the camper canvas is made for a exact drop of the side of the trailer so even something like a bigger or smaller tire can make it sit wrong.
The air bag idea certainly sounds to difficult for me for a little gain but go for it. I would make it so the camper top is made for the bags to be empty. So it makes the bed height lower to get into.

[revnkev]

I have replaced the rear coil springs in the Pajero with air bags (triple convoluted ones) and ended up using the pneumatic switches.

One $30 switch does inflation and deflation and has only one air line running to the switch and one to the bag,so two bags two switches,
the air bleeds out the back of the switch when deflating.

You do realise that if you connect both bags together (equalise)that unless you have air shocks or very high pressure gas shocks that can
support the trailer that it will just flop over to the heaviest side and stay there.

With a trailer you could maybe use some sort of load leveling device to keep the trailer level with the car (left to right) and let the equalised
air bags follow the terrain but then it's putting alot of load onto the cars rear suspension.

I've been thinking of using the airbags on my own camper trailer and if I did
I would have one air fitting from the cars air supply (comp & tank) to the trailer and two pneumatic switches on the trailer .
Simple and pretty cheap and no electricals to worry about.

[stinger]

Revnkev, where did you get the switches from (part number would be great )

I have just rebuilt my camper trailer chassis and suspension using components from a Vehicle Components (a trailer parts mob in Brissy) the full indepentdent set up from these guys, brakes, hubs, cross member, springs, shocks etc, etc was about $1200 To go air bag add another $1000.

Personnally I like the idea for all the reasons above. I have airbags on the rear of my 2003 Disco and love them. I now have a few spare airbags so I am going to add them to the trailer with either just a trye valve or the pneumatic switches fed from a cheap compressor and an old air tank I have lying around.

my 2c, cheers

[fat496]

I used to build tipper trailers for a living, and used to get solenoids, manifolds, airbags, airline, everything you need from Shephard Transport. Can't remember their number but just Google it. Speak to Steve or Luke and they'll point you in the right direction (if they still work there)

[MUD80D]

Revnkev, where did you get the switches from (part number would be great )

I have just rebuilt my camper trailer chassis and suspension using components from a Vehicle Components (a trailer parts mob in Brissy) the full indepentdent set up from these guys, brakes, hubs, cross member, springs, shocks etc, etc was about $1200 To go air bag add another $1000.

Personnally I like the idea for all the reasons above. I have airbags on the rear of my 2003 Disco and love them. I now have a few spare airbags so I am going to add them to the trailer with either just a trye valve or the pneumatic switches fed from a cheap compressor and an old air tank I have lying around.

my 2c, cheers

try this


http://cgi.ebay.com.au/air-bag-suspensi ... 1577wt_912

[revnkev]

Stinger,
I have purchased all my airbag bits and pieces from
http://myworld.ebay.com.au/airbagfactor ... X:SELLERID

He happens to be a local shop

The only part No. for the switches that I know is what is stamped on them
"3013-4" , they are a black plastic switch from USA with 2 barbed fittings on the back.

http://members.optusnet.com.au/~revnkev/mypic62.jpg

http://members.optusnet.com.au/~revnkev/mypic63.jpg

http://members.optusnet.com.au/~revnkev/mypic64.jpg

Hope that helps you.

[Breaker Brother]

Ok. so i was bored at work and flicking through wheeling magazines looking for ideas for when i build a camper trailer. I saw an ad for full airbag suspension in 4wd's and i got to thinking.....

Is there any reason why an airbag couldn't be used in the place of coil springs in a camper trailer? I was already going to use coils and links so that i have some parts changeability with my cruiser towing it.

I already have the issue of a trailer that is too low and sits hitch high when being towed by my cruiser, you could just adjust the air in the airbag to suit the height of the towing vehicle. (I run two sets of coils in the cruiser - one for touring and one for playing). It also means you could adjust the air pressure for differing levels of load. You could lower the trailer down when settingup camping or trying to get my bike into the back.

The trailer is going to have a removable camping module so it will spend a lot of it's life as a 8x5 trailer hauling stuff around.

What are your thoughts?

I realise there is an issue with punctures, but a shield could be made up. Also on long trips most people carry spare springs for their CT's. A spare deflated airbag is smaller and lighter than a spare Leaf or coil spring.

Something I've done quite a bit of homework on for my own project, go for a bellows style one, a good 8" bag will support 2600lb @ 100 PSI and are rated for up to 300psi. if you shop around you'll also get em much cheaper than coils, set up right they'll outperform a coil, you won't need a jack to change a tyre if it's tandem axle and they're easy as piss to make load sharing.

Jump on the Myswag forum, you'll find a heap on there who've done it

[stinger]

Sweet