Greetings, I'm looking for anyone who has built or modified independent trailer suspensions for off road use. I realize that someone will quickly either point me in the direction of Timbren axleless ones, or go through the you should only use ..... because of safety, or..... . Yeah I get that everywhere it seems. I'd like to make my own suspension for a up coming trailer build that I'd like to have as a dual purpose. I'd like to be able to have better off road abilities. That said, has anyone who is reading this, made their own? If so, what did you use and how did you go about it? I seen pictures in searches, but usually not much info. Thanks ahead of time! - Unholy
Looking for DIY independent trailer suspension information.
- Thread starter Unholy
- Start date
ottsville
Observer
Just ignore John61ct, that's what most of us do.
If you go over into the manufactured trailers forum here, there are some OLD threads in there about independent suspension that were really good. You'll have to do a little digging though, or maybe somebody has the links available.
If you go over into the manufactured trailers forum here, there are some OLD threads in there about independent suspension that were really good. You'll have to do a little digging though, or maybe somebody has the links available.
One of those really good threads is also cross-linked in one of the “timbren alternatives“ threads. Someone who preserved the suspension alignment by welding the independent arms to a straight trailer axle and then cutting out the middle after setting it all up on the frame. Very clever.
quickfarms
Adventurer
A trailer is essentially a three point set up. You have two tires and the hitch. Independent suspension is an advantage when you have two axles connected to a rigid frame. On a trailer the trailer axle is not rigidly connected to the truck because it will pivot about the hitch. So the only real gain is a little better ground clearance over the axle and this is probably of little value if the differtials on the tow vehicle are not raised
high-and-dry
Active member
In my mind the real benefit of a true independent suspension is dealing with slow rolling over large obstacles where you may be having one wheel way down, and one way up. But to truely be worth it the springs and shock need to be set up perfectly for the weight. And it really helps to have a large suspension travel, and I mean over a foot.
go watch the bruder exp 6 video and watch what there suspension can do.
go watch the bruder exp 6 video and watch what there suspension can do.
Louisd75
Adventurer
I'm of the opposite mindset. The Bruder EXP-6 is a tandem axle and, while the articulation is impressive it really only comes into play at slow speeds because it's a tandem axle. The EXP-4, which is a single axle, flops all over at slow speed, just like a leaf spring. You can see what I mean starting at the 45s point of this video (it should be cued up when you hit play)
ottsville
Observer
But don't forget the "expo-cool" factor.
Your point about multiple axles is valid and a good example is the lead image in the video @high-and-dry posted. Dual axles with the normal linked system on most trailers here in the US are probably at a bigger disadvantage in off road applications. Comparing axle clearance on a trailer to melons on the truck isn't exactly relevant as we can often maneuver a vehicle to straddle ruts where we may not be able to keep a trailer on the same straddle.
old_CWO
Well-known member
Airbags are a popular spring choice for custom suspension since they are so easily adjustable. As far as materials selected, the old engineer's adage applies: it depends. There is simply not enough information presented for anyone to make sound suggestions.
If you do an image search for "adventure trailer tass suspension" you can see how a reputable builder designed one and go from there. Most pictures of independent trailer suspensions I have seen online follow the same general layout as that with trailing arms, airbags and shocks.
Our Aussie friends seem to prefer coils over airbags. For an example see Opus campers. I believe they are an Oz import to the U.S. and have the coil spring independent. I have seen one of those in person and it's very well built.
As previously mentioned, most of a trailer's "articulation" is happening at the hitch point so the cost/complexity/gain of an independent single axle trailer suspension is a debatable topic.
Good luck!
If you do an image search for "adventure trailer tass suspension" you can see how a reputable builder designed one and go from there. Most pictures of independent trailer suspensions I have seen online follow the same general layout as that with trailing arms, airbags and shocks.
Our Aussie friends seem to prefer coils over airbags. For an example see Opus campers. I believe they are an Oz import to the U.S. and have the coil spring independent. I have seen one of those in person and it's very well built.
As previously mentioned, most of a trailer's "articulation" is happening at the hitch point so the cost/complexity/gain of an independent single axle trailer suspension is a debatable topic.
Good luck!
Peter_n_Margaret
Adventurer
For simplicity and reliability stick with conventional leaf springs just make them longer for a vastly improved ride and articulation and add decent dampers.
Cheers,
Peter
OKA196 motorhome
Cheers,
Peter
OKA196 motorhome
Martyn
Supporting Sponsor, Overland Certified OC0018
Build the trailing arms as strongly as you can as they take a lot of abuse off road. If you go with airbags make the upper mounts from 1/4” steel. If you go with coils adjust them for the load, if you don’t the results are not pretty. Do not link the airbags together, keep them independent. Do not for one moment believe that torsion axles, leaf springs etc. perform anywhere near as well as independent air or coil suspension. Your eggs will arrive in one piece and your beer will not explode when you open it. You will not feel the trailer moving behind the vehicle. Look at an old build Andre Shoumatoff posted on the forum on an independent trailing arm set up he made, I think it was one of the best set ups made by an individual.
quickfarms
Adventurer
I was thinking more about axle tube height. With the same tires the axle tube height on a driven axle and trailer axle will be almost identical.
As far as tracking goes if you keep the distance from the rear axle to the trailer axle the same as the vehicle wheelbase the trailer will follow in the vehicles tracks.
The 4 spring equalizer bean suspension used on most tandem axle trailers is not a good suspension for off-road. A much better suspension is the walking beam suspension.
In the construction industry the wholly grail of off-road suspensions is the camel back by Mack.
This is the type of suspension that the military uses.
If you want to see a good tandem axle trailer suspension look under a M1061
