Leaf spring vs Coil Independent suspension vs IS with airbags for mid sized offroad camper?

[Jman99]

Looking at a 6x4 offroad camper that has a tare of about 1000-1100kg & when fully loaded up weights about 1800kg. It comes stock with leaf springs, but can be upgraded to coil IS and even IS with air bags. I would like to go with just leaf springs for the lower cost and reliability. But my concern is on rough terrian with some of the trailer like the slde out kitchen, and all the electronics stored in a toolbox on front a frame, which includes about 400ah of lithium and victron mppt, AC chargers, dc dc chargers. So would IS coil & shocks do any good for me? will the leaf give a bad ride damaging things? I have read up on different types of suspension & most all simply say that IS is better, but that tells me nothing really.

ta.

 

[rehammer81]

I'd say first and foremost, no matter the chosen suspension design, your trailer must be riding on the correct spring rate for your loaded trailer weight. This is where the air bag suspension is nice because you are essentially tuning your spring rate for your current load based on the pressure you run in the bags and you can adjust for the terrain and speed of travel. Some properly valved shocks can benefit suspension control by dampening out the spring bounce a bit but not all trailer suspensions have room for shock mounting making proper spring rate even more important. IS, as opposed to solid axle leaf spring suspension, will reduce some of the left/right rocking that is more prevalent with SA/leaf as each wheel is not tied to each other. That being said, SA/leaf trailer suspensions don't articulate in the same manner as SA/leaf vehicle suspensions. The dynamics aren't the same. Not sure if any of that rambling helps.

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[Chi-Town]

The issues with air bags is you always have to carry a spare. if the bag pops and there is no bump stop to ride home you're hosed.
Now I know people will attest to the strength of the bags but all it takes is one wrong branch or random debris at speed and "pop!"

I'll take independent coil suspension over solid axle with leafs just purely on side to side load transfer on uneven surfaces. I've noticed it even on rough highway that my independent suspension trailer barely even moves over the bumps.

 

[Jmanscotch]

If money isn't much of an issue, then I hear lots of good things about the independent trailer suspensions. That said, the wife and I do very well financially and part of that is not being silly with the money. I say that to say, I hear so many folks comment that "this is the best", which can be true, but best for the money or best with money as no concern? I've learned some recently that I'm a big fan of "best for reasonable money". So depending on what your priorities are, well that helps decide if independent or SA/leaf is best.

I built my own off road camping trailer (twice), all because spending $30K on the one I wanted was just silly. We run leaf suspension on ours and have zero complaints, for how we use it.

We do light off road trails, at most, I'd consider some medium difficulty, nothing rated difficult by most standards. Our goal is remote camping, not serious off roading. We did equip our trailer with Jeep CJ-7 leaf springs, shocks and 4" lift. It tows amazing, has a simple and easy to find parts for suspension and only if we made stupid money (and thus could just afford to experiment and change suspensions a few times) would we bother going another route.





Stock trailer leaf springs (still installed) with Jeep leaf springs installed as well, for comparison:



Honestly, for what we do, I have zero issues with a solid axle and leaf springs. As rehammer said, having them set for the right weight (and use) is important. Our CJ-7 leafs are from the rear of a CJ-7 and the weight the rear axle holds is approximate to the weight of our trailer.

Here's the other trailer we built, not jeep suspension but rather some off road specific trailer ones from a guy that builds custom trailers. No shocks even and it did great.






As Chi-town says, non-leaf spring systems are a bit more complex and specific and yes, sure, they help with side-to-side weight transfer, but I'd argue that doesn't make a huge difference (for the cost) compares to a SA/leaf. Plenty of off road vehicles do very well in situations with SA/leaf when IFS/IRS vehicles struggle, so none of this is 100% one route. It depends on how you use it and what you expect. For budget minded off road trailers, on mild/medium trails....my opinion is a correctly rated/sized SA/leaf setup is more than adequate. Spend that saved money on other upgrades or on investments.

Our trailer is a 5x8 and weights about 1,400 lbs (635 kgs) loaded to go.

Also, my username is Jman as well, so you know you can trust me lol

Jake

 

[Boss Hugg]

Not to hijack a thread, just want to draw some more out of the conversation. What about using air shocks rather than air bags? I just picked up the stuff to build my own IS, but I need to decide between bags or shocks.


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