CARAVAN STRUCTURAL FRAMES

Hi Ronswon,

I don't think either type is the "best". The quality of the van builder is MUCH more important IMHO than what type of frame it is.

Aluminium frames have the potential to be very good, but it depends on the grade of aluminium, the thickness of the channel and the way it's joined (rivetted, spot welded, bolted etc...). As a building material, aluminium is prone to stress fatigue and unless its built properly you can get stress failure of the joints. However, it is impervious to water damage and generally much lighter than a similair wood frame. It can also be more rigid, but IMHO than is not always better!

Meranti frames have stood the test of time, but they are suseptible to water damage if you have a leak. The design and build quality is a big factor, as you could imagine a poor join would make an otherwise good design weak. But meranti does not suffer stress fatigue like aluminium.

A caravan structure is not "rigid", it must be able to move around to a small degree. For example, if a carvan was say all glass, it would bleep ter as the chassis flexed on the first bump in the road. A more rigid chassis helps reduce flexing, but ALL chassis's move to some degree.

Offroad chassis are generally 6" beams compared to their 4" onroad eqivalents (generalising here) and often have more crossmembers. This significantly reduces flexing and is one of the main differences between off-road and on-road models. Typically offroad designs have better suspension with shocks, mainly to control killer corrugations. Note that it is corrugations that destroy caravans, not so much the very slow going on tight and twisty tracks offroad tracks.

Even though you plan to spend most of your time on the bitumen, I would still consider an offroad van. Not because you are doing a big amount of gravel, but because offorad vans are generally stronger. Even if you never go offroad, the stronger chassis and better suspension will ensure you van (and its contents) has a better ride.

As I said earlier, the type of frame is not so critical. There are plenty of both doing laps of Australia and none has shown to be significantly better, they both have their advantages and disadvantages. I would be much more concerned with the type of suspension the van has (should be independent with shocks IMHO) and caravan build quality.

Typically, if the outer structure and inside fitout is of high quality, the hidden frame will also be good. However, if what you can see is poor quality, how good is the hidden inner frame???

Just my thoughts.

Cheers

Captain

Like the Captain said. Build quality is paramount in deciding. I have had both frames and each time it comes down to quality. If the van is a high quality you can be assured that the frame is of equal quality. most good companies will let you inspect work in progress if you need to see how well they are constructed.

Good advice from captain, but also consider this.
A good friend recently (10 months ago) bought a $65,000 van, very good well known and respected brand.
After a few weeks of intermittent rain, a few storms etc over xmas he discovered to his horror that his roof was full of water... So all his TIMBER FRAMING was wet. Now he has sleepless nights wondering 1. has it been fixed properly? and 2. what long term damage has been done?
Both he (and I) will buy aluminium frame next time.

P.S. I sold a 23 year old Viscount about two years ago (aluminium frame) and it was structually as good as the day it was made. I had done some major mods on it and the frame was perfect.