When it comes to demountables it’s all about weight, weight, weight. Every kilo you load behind the rear axle lightens the load on the front axle and moves it instead to the rear axle.
‘One ton’ load capacity doesn’t mean a 1000kg hanging out the back of the truck. The maximum load is made up of driver & passengers too (more on that later). The load area is also actually quite small, especially with a double cab, so many demountables extend a long way aft of the load bed. Of course the further aft the weight is carried the lower the effective carrying capacity so to put the buyer’s mind at ease some demountable manufacturers simply understate the weight of their campers. This has been happening for decades even with well respected brands and there are well published accounts of cabins weighing up to 40% more than their claimed weight.
Overly heavy cabins are therefore far from uncommon and we regularly come across owners running dangerously over inflated air bags and tyres inflated to the max in an effort to compensate for their overweight and overloaded campers. This is most definitely not a solution, the car still drives like a pig, it’s dynamically unstable and puts a potentially intolerable strain on both car and the driver. Something has to give and it is not uncommon for the chassis to break under these circumstances.
Double Cab vs 1.5 Cab:
On a typical double cab a third or more of the truck’s ‘payload’ is intended to be carried in the cab (i.e. driver and passengers). With almost any 4×4 double cab pickup almost the entire load area is behind the rear axle. Any camper must therefore be both extremely lightweight and possess an extreme forward weight bias.
Note the difference with a 1.5 cab. With a well designed camper nearly all the weight can now be carried above or in front of the rear axle. You still have to watch the weights of course and if you want to carry a reasonable amount of water and supplies you probably want to keep the cabin weight below 600 kg, but you do have a lot more scope.
Of course how you load your camper is also crucially important. Choose your equipment carefully and don’t load it with stuff you don’t need – just because there are cupboards everywhere doesn’t mean you have to fill them. Naturally heavy stuff should all be loaded as far forward and as low as possible.
Water is very heavy, a kilo per litre, so take only what you need and try to avoid driving with grey and black tanks full. Remember every kilo really does make a difference.
Finally some brands offer a software update for the ESP system to take account of a higher than standard Centre of Gravity. Your dealer will be able to give you more information. He will also advise you that this does not in anyway compensate for over and/or poor loading!
Light weight and good weight distribution cannot just be an aspiration, they are both absolutely crucial. You can have the most luxurious, underfloor heated palace ever created, but if it’s overweight it has no place on your truck.
Quite apart from anything else, with the current breed of trucks bristling with computers correct loading is even more important than ever before. If the balance of the truck falls too far outside the parameters of the ESP and other electronic safety programs the computer may behave unpredictably or even inappropriately in an emergency situation.
Every camper in our range is designed and built with this in mind but the way you load it is crucial too. It is the owner’s responsibility to ensure that options and loading do not exceed vehicle manufacturer’s recommendations and Gross Vehicle weight (GVW), individual Axle weights and Centre of Mass guidelines must all be strictly adhered to. If you bring all your camping gear when you come to collect your new camper (make sure your fuel tank is full too!) our load cell system can measure the weight on each wheel for you to make sure your truck is happy before you leave.