Trailer Suspension - Air Over Leaf?

[bugnout]

Anyone tried this kind of setup on thier expedition trailer? The basics of the design as far as I've been able to gather is a longer softer set of leaf springs with airbags directly over the axle. I think this setup is used by OTR trailers.

Might be simplier to set up and easier to maintain than trailing arm suspension.

 

[yeler]

will the cost out weigh the function ?

leaf springs work just as good dont they ?

what would the advantage be ?

Just a few questions I will be waiting to see answered

good luck with the outcome

EDIT: just looked at your Jeep link "My Mods" wow nice trail runs

 

[Titanpat57]

Those springs are very reasonable in price. I think it would work great on a heavier trailer.

 

[Martyn]

It's a viable option.

Typically trailer springs are short and stiff, not ideal for off-road.

Taking a longer flexible leaf spring, many people are using Suzuki Samurai springs, to improve the flex is a good fix for softening the springs. The air bags will then allow you to maintain your ride height as you load the trailer.

This is a workable solution to the issue that leaf springs have, they have to be designed for maximum load, which is why trailers bounce around if empty of half full. Leaf springs also compress with load and reduce the amount of available travel, the air bag will maintain the ride height.

What it won't do is change the characteristics of a solid axle which is to transfer movement from one side of the trailer to the other, rotate the tire inwards when the spring is compressed, and change the axle position if it's on shackles. For that you'll need independent trailing arms.

 

[yeler]

then why not design an IFS set up off say a 86 or newer Toyota and use that on yer trailer, get some air shocks and set them in the springs and still have the flex and adjustability and comfy ride.... just a thought

 

[Deleted member 13060]

We used to do something similar when lowering Mini Trucks. Kept the long main leaf in the rear to locate the axle and added airbags. It was cheap, easy and worked. The only issue was axle wrap but that's not an issue on a trailer.....

I think it's a great idea and may have to steal it for my trailer.....

RON

 

[yeler]

forgive me for not "getting it" but why would you need to do this ?

is it a load issue to much weight or what ?

cause I would think leaf springs would be just fine. Im using rear XJ springs and fully loaded it rides just fine.

why would you spend the money on airbags when leaf springs work fine, Im just curious educate me please gang :lurk:

 

[Hannibal USA]

We use full YJ springs with shocks...works great and you can adjust the ride height with the size spring and shackle, you can also get different spring rates too. The good thing is its a proven durable set up....

 

[bugnout]

Thanks for the reply's.

I think number one goal is better washboard road performance. Be nice to get to camp with all parts still attached and not have to go around a retighten all the fasteners.

Martyn, I really like the trailing arm, airbag shock setup like on adventure trailers, but also like the durability and low complexity of leaf springs. At this point, going trailing arm is the most expensive option. I may get there eventually.

Chris, My first thought was just to add shocks to my current setup. But came across this and started wondering if airbags and taking a leaf out of the spring pack was a better choice for handling washboard roads.

 

[java]

i have been thinking of going this route. airbags with a main leaf. what it offers for me is ability to change the spring rates for different loads. i want to let some air out of the bags when carrying only my dirtbikes (500 lbs) and then be able to add some if i need to haul a lot of gravel.
it allows you to adjust the ammount of weight capacity so that its not just bouncing like its empty with just a light load in it.

 

[Martyn]

The key to this is the variable load in the trailer vs. the leaf spring that is set for maximum load. If you read this article you'll see that trailers can exceed their unladen weight by 285%. Most SUV's have a maximum load rating of 55% over their unladen weight, so leaf springs will work better with SUV's than trailers.

Yes leaf spring come in all shapes, sizes, and ratings, but they are not ideal when it comes to dealing with such huge variations in load.

Leaf springs work well when the load in the trailer is constant, and approaching the maximum range, as in military usage. For civilian use where comfort, transfer of movement from the trailer to the tow vehicle, damage of contents, and smoothness of ride is important you have to think outside the box.

 

[Hannibal USA]

the leaf spring that is set for maximum load.

Actually no they are not, this is why they have a leaf pack that is made up of multiple leafs at different lengths and a final over load for the bottom if needed for your standard common leaf spring set up. just like Airbags or any other suspension the spring rate increases with travel to slow down the bump, or increases the spring rate under load conditions.

Look at Deaver leaf springs, made up of many smaller leafs to give the best ride off road, a lot of desert race trucks use this still to this day for the best travel and ride in race conditions
http://www.deaverspring.com/

 

[Martyn]

Actually no they are not, this is why they have a leaf pack that is made up of multiple leafs at different lengths and a final over load for the bottom if needed for your standard common leaf spring set up. just like Airbags or any other suspension the spring rate increases with travel to slow down the bump, or increases the spring rate under load conditions.

Look at Deaver leaf springs, made up of many smaller leafs to give the best ride off road, a lot of desert race trucks use this still to this day for the best travel and ride in race conditions
http://www.deaverspring.com/

May be instead of say " Leaf Springs are set for maximum load" I should have said they are "built for maximum load". When you look at the huge load variables with trailers, plus 285%, you end up with a leaf spring that's over kill at lighter loads.

As you say they work well with desert racing trucks. but their only load variable is fuel.

 

[Hannibal USA]

May be instead of say " Leaf Springs are set for maximum load" I should have said they are "built for maximum load". When you look at the huge load variables with trailers, plus 285%, you end up with a leaf spring that's over kill at lighter loads.

As you say they work well with desert racing trucks. but their only load variable is fuel.

fuel and different terrain from smooth to 10 feet high jumps.

If you use a good modern leaf spring they ride nice loaded or unloaded if you pick the correct set up.
beside most people would be towing their trailers loaded 90% of the time, so either setup built to ride nice while loaded will work fine.

We will have our trailing arm airbag set up available as a option, in about 45 days after the testing.

 

[Martyn]

Glad to see you're thinking outside the box.