What makes a caravan a true offroader?

Robert Pepper visits the Bruder showroom and discovers a true offroader caravan.

Off the top of your head, could you name all the car manufacturers in Australia? Maybe not, but I bet you’d come close and maybe miss out on a couple like LDV or Lotus. And if the ones you missed were mentioned, you’d recall them.

Now try the same with the makers of travel trailers – camper, caravan, hybrid etc. Not a chance. Not even people in the industry could do it.

So there’s a lot of choices and a lot of competition. And a lot of buyers who are often price-driven and looking for specific features. This is why we see pointless mud tyres on large vans, two spare wheels and ‘offroad’ slapped on chequer plate adorned trailers with shiny shocks to produce a van that is, at best, dirt-road capable.

I’m also permanently disappointed by the lack of engineering dynamics and innovation. Many makers buy a chassis and build on top, with no regard to factors such as suspension design or aerodynamics. This is why Bruder caught my eye. They appear to have worked a little harder on these things. Much more so than the average builder.

I visited their showroom to talk to the Bosschieter brothers who founded the company. What follows is what I learned, but it’s not a review or any comment on how well it’d work in practice. I have been offered a Bruder to test and if that happens then I’ll be able to provide an opinion. The caravan I examined was the Bruder tandem-axle EXP-6, but the designs are broadly applicable to the single-axle EXP-4 and larger tandem EXP-8.

Check out the Bruder EXP-6 off-road expedition trailer caravan here:

Let’s start with the suspension on the Bruder EXP-6 caravan

Let’s start with the suspension, which is the key to how any vehicle handles, trailer or not. The Bruder EXP-6 caravan has air spring suspension and there are controls to separately raise the height of the left and right of the vehicle. This means you can change the ride height – relatively low for high speed, and raised for difficult offroad terrain which demands clearance. There’s also an auto-level function, so no need to back the trailer onto levelling ramps.

Tiny little things like that I love as they reduce what I call the ‘friction of camping’ – the chores that have to be done to live.

It is also possible to independently adjust each wheel’s height. Each of the four wheels has a lock-off valve so regardless of what air is pumped in or released, then that air spring is unaffected. This allows you to drop one side, strap a wheel so it doesn’t drop down as the suspension is raised, raise the suspension and then that wheel is off the ground and you can change it without a jack. And lowering the trailer is handy for storage or sneaking under low trees.

Load-sharing vs non-load sharing suspension

The suspension can be set to either load-sharing or non-load-sharing. Non-load-sharing suspension is what caravans normally have. The front and rear wheels on a side have suspension entirely independent from each other (as distinct from independent suspension in the sense of the left and right wheels on an axle). This means that if say the front wheel goes up, the rear is unaffected. This is okay for on-road use as the road is flat but off-road, it’s a problem as you can have one wheel on a side in the air.

A load-sharing suspension is the opposite. As one wheel goes up, the other is forced down. This means both wheels maximise contact with the ground. Bruder achieves this by cross-linking forward and rear air springs, so as one air spring is compressed the air is forced out of the spring and into the other wheel. Or, the valve can be locked off and you have non-load-sharing. The air suspension also allows you to vary the pivot point of the trailer which in effect changes the tow ball mass.

The Bruder chassis is unusual for a caravan or trailer

The chassis is unusual as it has a raised rail for the shock absorbers so they can operate in the correct geometry. If you look at most vans the shocks are often quite horizontal, nowhere near the orientation required for maximum effectiveness. The body is fixed to the chassis by mounts similar in concept to those used for-body-on-frame vehicles such as utes like the Ranger. That design offers some insulation for the body from the shocks of the road.

Aerodynamics

Bruder has also done aerodynamic testing and that’s why there’s a curved rear section for reduced drag. That’s also a bonus for international operations too. There’s left and right-hand drive countries so while our caravans are left-entry, that’s not good for left-hand drive countries.

International operations

Bruder has generally made international operations a focus. The vans are only 2m wide so easily fit in a shipping container and don’t require tow mirrors. The electrics and other systems are designed for multi-country operation and the van has no gas, just a lot of lithium batteries and solar panels. Wheels and tyres vary from 33-37″ and can be PCD and track-matched to the tow car. Brakes are discs on each wheel.

The underbody is smooth, designed for offroad and there’s a small winch at the rear. Even the jockey wheel is easily detachable.

I could go on but that’s enough for one article. It was pretty interesting to look at a true offroad trailer as opposed to something that’s just been badge-engineered.