Thread: time to create my vision of the ultimate off road camper

Originally Posted by LandieMan

Thinking about it, I wonder if a well load balanced tandom would in fact have a lower rolling resistance than a single axle for a trailer of the same weight? Less weight on each tire means less tire deformation which means less resistance to rolling??

There's no doubt a single axle is more manouverable on level ground with good adhesion because of the scuffing with a tandom. But in a relatively straight line on an uneven, loose or soft surface I wonder if a tandom of the same weight would in fact be easier to pull?

It would certaintly make an interesting practical test to compare the two scenarios.

Cheers, Iain

P.S. How about an independent tandom with air bags so you could lift one wheel as required and have the best of both worlds??

Doubt it... Problem often occurring is incorrect tyre pressures on trailers, mainly because the operator rarely knows the exact weight to be able to calculate the right pressure using the data on the tyre side wall, and there is no simple chart like on cars – get that right and it should not be an issue (assuming the correct tyres for the task is fitted) – theoretically you would have less resistance per tyre but you have twice as many.
You are also adding considerably to weight for no good reason.

Only thing I can see is it MAY add to floation in soft sand but still the extra weight......

Originally Posted by harlie

...theoretically you would have less resistance per tyre but you have twice as many...

Good point.

Heres my 2c worth.

For quite some time I researched this issue, as we were in the market for a decent campertrailer. We ended up hiring a Cape York out of Atherton. We took it across to Isa, Cloncurry, Lawn hill and camooweal etc etc and also heaps of remote side trips. We now own one due to it fulfilling all the requirements and fiting the budget.

It's use of Toyota Hilux rear spring packs and shocks, 6 stud hubs, 11" Alko electric brakes and 15x7 sunnys was a good idea. Everywhere we looked there was TOYOTAS and NISSANS etc with these wheels, springs and shackles. Trailer shops in every major centre stocked Alko hubs, bearings, wheel studs etc. I am often asked why I didn't convert to 5 stud LR pattern to match the Rangie, the availability of spares is definately a big issue for me.

JC

Originally Posted by justinc

Heres my 2c worth.

For quite some time I researched this issue, as we were in the market for a decent campertrailer. We ended up hiring a Cape York out of Atherton. We took it across to Isa, Cloncurry, Lawn hill and camooweal etc etc and also heaps of remote side trips. We now own one due to it fulfilling all the requirements and fiting the budget.

It's use of Toyota Hilux rear spring packs and shocks, 6 stud hubs, 11" Alko electric brakes and 15x7 sunnys was a good idea. Everywhere we looked there was TOYOTAS and NISSANS etc with these wheels, springs and shackles. Trailer shops in every major centre stocked Alko hubs, bearings, wheel studs etc. I am often asked why I didn't convert to 5 stud LR pattern to match the Rangie, the availability of spares is definately a big issue for me.

JC

Hi JC, Your point here is exactly why I am not interested in LR wheels, independent coil or AL-KO’s IRS for my trailers currently in construction. Keep it simple and commonly obtainable...

Originally Posted by harlie

Agree with above - 4 wheels are not going to be as good as 2 for off road, there is some excellent points above.

AL-KOs "outback" spring sets go up to 1680kg on one axle – there are a lot of them bouncing to the cape and back, weak point is where the front spring bracket is welded to chassis, the springs and components usually out last the chassis, so it is up to the builder to unsure that is strong.

With independent you get more ground clearance but what for – as Dave point out, a basic trailer axle has more clearance than the diff on the 4WD and it will go through first... so it now comes down to strength.

Welding on my trailer starts tomorrow - might start a new thread, if anyone is interested to show what we (brother and I are building 2) are up to. Camper is based on 7 x 4 but will be slightly larger (2180 x 1260) internal and will transport a 4m tinnnie - we have CAD designed (read wife is engineer) the lot and have folded all the sheet metal ready for welding tomorrow. Body to be aluminium with the monster of all chassis in mild steel.

H

Quote: "With independent you get more ground clearance but what for – as Dave point out, a basic trailer axle has more clearance than the diff on the 4WD and it will go through first... so it now comes down to strength."

Need to point out that independent suspension does not increase ground clearance, it actually decreases it.
When the wheel and tyre travel upwards, as in going over rock/bump the pivot point and the chassis drop accordingly, decreasing ground clearance. What's the saying, "For every Action there is an equal and Opposite reaction" or something like that, cant beat the solid axle for off-road, Wheel goes up, Axle goes up, Regards Frank.

Originally Posted by Tank

Need to point out that independent suspension does not increase ground clearance, it actually decreases it.
When the wheel and tyre travel upwards, as in going over rock/bump the pivot point and the chassis drop accordingly, decreasing ground clearance. What's the saying, "For every Action there is an equal and Opposite reaction" or something like that, cant beat the solid axle for off-road, Wheel goes up, Axle goes up, Regards Frank.

Good point – BUT when it comes to trailers that is not quite right. The independent coil systems fitted to high end campers all pivot from the trailer sub frame, which is always higher than a straight axle will be. So yes as the wheel travels up, the chassis drops - exactly the same as with a live axle, but all independent suspension components remain above the height of the stub axle and where a std leaf pack would be... and because of the pivot point they will remain that way. So TRAILER independent suspension will have more clearance - they are very different to automotive setups. Not to mention the absence of the beam axle across the width. As I said above it’s pointless anyway...

x3 please