All terrain trailer suspension, your choice

[phenopd]

What about a wishbone setup with a central connection then trailing arms back to a straight axle? With possibly coils or airbags. I saw this on a rock crawler and wondered if this could work with a trailer? It would need a track bar, but, it seems it would easier to set up than the separate independent arms. I'm no engineer, but it seems like a simple setup.
Does anyone see a flaw in this design? I would love to hear some feedback on this idea. I hope I explained it clear enough.
Mike

 

[ntsqd]

Sounds like you are describing the rear suspension of a Model A Ford. They have a live axle with a centerline ("Torque") tube running forwards to a single pivot on the rear of the transmission. Then there is a diagonal link on each side of the centerline tube fixed to both the axle tube near the wheel and to the centerline tube near the pivot. In the Ford's case the spring is a transverse leaf spring anchored to the frame at the center.
The VW Rabbit rear axles are also similar in layout, as are the rarer Saab 96 rear axles though both of them use coil springs.

The point of going independent is so that the bump one tire hits does not affect the other tire. All live axles suffer this trait. One tire hitting a bump influences the other tire mounted on the same axle.

 

[phenopd]

Yeah, I see the point. I am looking at this trailer that has a straight axle and was thinking that that would be a little more simple to set up than the independent route. Someone did mention , I think in a different thread, setting up the straight axle w/ the independent arms, then cutting out the middle to facilitate ease of setup. I'll probably just leave it as is for now.(leafs)
Mike

 

[Martyn]

I have to agree with you, if they used in the army trailers during the war they have to be reliable

The benefits of reliability seen in military trailers doesn't lend well to the more flexible ride preferred by expedition trailers.

Suspension design on a trailer is very straight forward if all you want to do is fill it full of 750 lbs of ammo. Reliable and straight forward it is. But modern expedition trailers have huge weight variations, say from 1500 lbs empty to 2500 lbs full. An increase in mass of 67%. At all of these variations the owner wants the trailer to perform well. The trick is trying to get it to do so.

I think this is why you see so many variations and designs.

 

[Chucaro]

Martyn, your points are very valid in countryes where the next town is about 100 to 200 km. Here in Oz if the suspension breaks in the Cape York os the far out back the only alternative is to live the trailer on site. Leaf springs are easy to fix in a remote area. This is another aspect way the Oz army are using leaf springs.
Fatigue in the leafs can be a problem that can be aliviated by fitting shoks.
I am interested in a feed back from you regarding reports of break downs and solutions applied by your customers when the problems occurred in remote areas.
Cheers

 

[Martyn]

Martyn, your points are very valid in countryes where the next town is about 100 to 200 km. Here in Oz if the suspension breaks in the Cape York os the far out back the only alternative is to live the trailer on site. Leaf springs are easy to fix in a remote area. This is another aspect way the Oz army are using leaf springs.
Fatigue in the leafs can be a problem that can be aliviated by fitting shoks.
I am interested in a feed back from you regarding reports of break downs and solutions applied by your customers when the problems occurred in remote areas.
Cheers

Chucaro

No major issues. It all seems to be the same things common to all trailers and owners. Preventative maintenance, repacking and adjusting bearings, checking airbags for ride height. On a trip looking at the trailer in your rear view mirror for any unusual behavior. Safety inspections every day.

The strangest thing we have had is a hub cracking, but that could happen with any suspension system.