Is it better to have single or tandem axle for dirt driving.

I have been told that tandem is better than single. Our size we are looking at is 15'9 and we will have enough weight for single axle.

Thanks,

"Better" is a qualitative term that everyone will interpret in their own way, so it makes it hard to answer the question.
I have a 16ft Gazal single axle that has had the axle underslung to give more height clearance. In 5 years I have done over 3000km on gravel roads, and some pretty ordinary, without any problems. In my opinion it is far more important to have your car and van set up so that they are level, that the van is loaded correctly so that the ball weight is within specs for your towing vehicle and that a weight distribution hitch is applied if required. On top of this, if you drive for the conditions then you should not have any problems with a single axle van.
You will also be told that you must have independant suspension for offroad. Unless you are doing serious offroad work on uneven tracks then, in my opinion, this is not essential. For the majority of gravel roads a single straight through axle on leaf springs will do the job for you.

Hi Kootyman,
Both single and double axles will do the job but generally when you buy a van it is not until they reach a length of about 17 to 18ft before they have double axles. I think this is mainly because the weight starts to get up and one axle set is not enough to carry the weight. Vans with toilets and shows usually have double axles as the weight is a bit to much for one axle set but sometimes you can find a toilet and shower van with one axle set. Chassis would also need to be extra heavy to span 18ft with only one set of wheels. The other problem would be weight distribution would need to be very well thought out with long vans with one axial set where as two axial sets are more forgiving.
If you are doing serious off road caravanning the shorter the better and if you really get in trouble a small van can be man handled with one set of wheels.
On bad roads the softer and more controlled suspension is the best as this will help save the van body and interior from vibration and stress.
As Rayw1 has said you can travel on single straight though axle on leaf springs but just take your time.

JR

Thanks for the great info.

The van we are looking at is only 4800mm or 5'7 long and under 2000kg dry (hopefully) with Alko independent rubber suspension.

I have just been through this with the order of my new van.
Mine will be 2000kg wet with the same suspension.
I knew I was going to drive dirt roads and "upgraded" the ALKO to include shocks- this is an ALKO option - cost was very reasonable as well.

I plan to upgrade the wheel tyre package from the 15" to 16" rims and All terrain tyres to further enhance the offroad ability. Afterall if going to a single axle there is no redundancy in the case of a flat.

Hi 4wd26,
Yes getting a flat with only two wheels usually means a destroyed tyre. I have an 18ft van with only two wheels and have been considering one of those tyre pressure temp alarms. If your van is getting up around 2tonne with only two wheels you will need.

JR

My 2c on the issue:

A popped tire will be far easier to control with 3 still on the road than 1 (and is more common on gravel)

If you're venturing into remote areas you can stuff your spares, and 2 on your van, and still limp back to civalisation on only 2 (slowly taking great care)

One reason I read for independant on the van is so that the beam axle doesnt hit the berm of sand up the middle of some roads/tracks. That's a load of BS. If you're towing in those sorts of areas, you'll be in a Landcruiser, Patrol, Deffender or F Truck, and it will have its own beam axle knocking the berm down. No matter what suspension is used, if they're running interchangable wheels and tires the axles will be at the same height from the road.

The Alko IRS with shockers is as good as they come and is certainly my personal recommendation to those that want the best.
The proportional compression really works a treat both for the bound and rebound actions. It's also the suspension of choice by Barry Davidson of DRV (Cabcar) and Phoenix vans along with the likes of towing guru Collyn Rivers.
Cheers, ozjohn.