Thread: Who has shocks on their leaf spring camper?

8" of travel!!!!!!!

I would have thought with leaf springs you might get 2" travel.

Thats why I talked about the Falcon wagon or ute springs. They were designed for 12" travel, and these are what I would put on mine!

I'm still trying to decide if I want to build a camper based upon the Sankey design concept. I would like to but is it just another hobby toy for me? Barbara does not always approve!

Yes, well I still might end up going for another spring in the end. I want to build this up and then test it and give the spring company the benifit of the doubt since they recommended this spring.

But, I welded on the springs yesterday arvo and then mounted them on the axle and the springs seem very very very hard to me. Again, they are meant to be rated to 750kg (375kg/side) but with just the chassis built I tried pushing down with all my weight (and I have a lot of that) and I could not budge the spring even the slightest.


I am not sure of the technical aspects of leaf springs. How do you have a leaf spring that will carry the weight yet still be supple? With a coil, you make it soft but long then when it is installed it compresses but still is soft.

I am thinking you want a leaf spring that can flex a lot without hurting it (ie cracking or getting weak spots) and has a fair bit of curve in it so it sits high before it is loaded up then squashes down when loaded but still has plenty of room to flex more. This sound reasonable?

When they rate a spring at 375kg like the one I have does this mean it will not deform at all until it is loaded with 375kg???
When the spring is fully loaded will it be "more supple" than it is now?


I should have gone coils....at least I understand them!

Truthfully I don't really care about articulation. At slow speeds you can drag a trailer over anything.
What I do care about is for the suspension to work at high speeds on the corrugations. So it only has to move a couple of inches but it has to do it easily and hundreds of times a minute. I will have to find some rough corrugated roads around Melbourne somewhere to test it out when finished.

I put shocks on my new box trailer (8x5 ft) a while back to stop it hopping around. the're near vertical, short and fat... and came from a wrecker; he said ex Mazda (the little truck with the 12" dual rear wheels) cost not much and seems to be better for the trailer (and the load of bikes), as in its not shaking itelf to pieces or the cargo, unlike the previous trailer. The shocks are doing their job, keeping the load under control, remember, they're not springs.....

I once towed a caravan round Aussie which shook itself to bits over 12,000 miles, but if the axle had been tied down like a decent suspension system in a car, the damage to the van would have been minimal, my opinion, but the physics (harmonics?) do add up....

GQ

I would imagine with so many leaves the majority of suspension comes from the tyre sidewalls.

I can assure you that as an engineer working at Ford I designed leaf springs for the Falcon wagon that had 12" theoretical travel. In real life they had well in excess of 11". I also worked for the company that made the very same springs and we tested them on a hydraulic road simulator with 12" travel. Believe me they work!

I would put such a spring onto a trailer with travel limited to about 10-11" limited by the bump stop and shocker extension.

If you want to go another way then you can replace the front half of the leaf spring with a rigid tube bolted to the axle and swinging from the front eye, but using either a coil spring or air bags. This will give you a similar ride situation.

If you are really concerned about corrugations then go independant. Same as above but instead of a single tube axle make two swing arms from the side. You will end up with a longitudinal radial arm and a cross radial arm giving a swing curve which changes the steering characteristic on role. This is what TVan have done, but with coils.

How sophisticated do you want to get? I still hang my hat on the long leaf springs for low cost and reasonable performance.

this is what is under my camper trailer.....

pretty dam fine bit of gear IMHO