HOW MUCH CAN WE REALLY CARRY UP TOP?
Travelling outback in the FJ40 Shorty back in the 80s, we were fortunate to have no major incidents on the road. Many challenges involved dodging kamikaze emus intent on out-running our vehicle, or enduring the endless corrugations for which Australia’s back roads are renowned. But I distinctly remember our 4WD striking a patch of loose bulldust on a rising camber one day and feeling the whole vehicle begin to tilt over with its high centre of gravity amplified by the three jerry cans, a spare tyre and a tent loaded up top. Fortunately, our vehicle recovered traction before its rubber feet were pulled out from under it. But I remember thinking that the sensation was not one I’d like to see repeated.
For the most part, the issue of vehicle over-loading is one to which we may give little real attention. And, to the extent we do, we may think it’s someone else’s problem. After all, we’ve probably all seen hundreds of images in our lifetime of trucks, tuk-tuks, motorbikes and bicycles bulging at the seams with produce and people – and the context are often from overseas. Driving our well-equipped 4WDs with their custom-fitted aftermarket roof racks and other cargo carriers, it’s easy to think that we’ll be able to safely meet any load bearing requirements we may have, regardless of what we choose to take on our next overland adventure.
The reality is that many roof racks will handle no more than 50-100kg of load (depending on the make and model).
And when it comes to the rigs to which we attach these racks, many vehicles recommend a maximum roof carrying capacity of around 70kg, and that includes the weight of the rack itself. When we consider that a single full jerry can will weigh about 20kg, it doesn’t take much imagination to think of situations where these recommended limits will be exceeded.
Should we worry? There’s plenty of online discussion about just how much is too much when it comes to stacking up the roof racks, with some favouring heavier loads than the manufacturers’ recommendations.
I’m not one of these people. The risks of top-loading were reinforced to me a couple of years back when we were in the Flinders Ranges and hit a wash-out. With a Tirfor jack and a spare tyre strapped above the cabin, our roof racks and cargo carrier were at their limit, but within load-bearing tolerances. While we weren’t travelling quickly, the dynamic force of the strike was enough to crack the side rail mounts and to dent the roof rail. The two days we spent at Wilpena Pound Campground undertaking running repairs was a relatively relaxed end to what could have been a nasty incident.
So for my part, I’ll be sticking to what the user manuals say. I know the real risk of damaging our vehicle’s roof rails and irrevocably changing our vehicle’s centre of gravity – and its steering – when we start getting top heavy. And I like our vehicle to brake when we want it to – so I’m conscious of the difference between static weight and the relative weight of the load and what this may mean when we’re moving at speed. Most of all, I don’t like the small print in our vehicle insurance policy that leads me to think that we wouldn’t be covered for damage and third party injury if we were involved in an incident with an over-loaded vehicle. A sobering thought.
Ultimately, I don’t want to be worrying about our load. I know that if we pack the vehicle correctly, and within load-bearing tolerances, I can travel comfortable in the knowledge that I won’t see 70kg of recovery equipment and roof racks deposited on our vehicle’s bonnet next time we hit a wash-out.
“The reality is that many roof racks will handle no more than 50-100kg”
LEFT: Really think about what you’re packing up top. BOTTOM: Careful loading is required for safety and insurance.