THE BIG DASH: Hitting the scales

Just like any automotive form, weight is the enemy of towing a caravan.

The heavier you are the greater your fuel consumption, which is obviously a key concern right now!

But it’s not only how much weight your combination adds up to but also how that weight is distributed across your tow vehicle and 'van that matters.

There are legalities and safety issues to consider here. If you’re too heavy and the police pull you over for a weight check - which they do in some states - then you’ll have to fix the problem on the spot or leave your 'van behind. Either way, you’re getting a fine.

Worse, if you have an accident and your insurance company can prove you’re overweight then you won’t get a payout.

If the weight isn’t apportioned correctly then the dynamic behaviour of your rig is going to be compromised and that potential accident becomes more likely.

So getting the weight right is vitally important. I kinda appreciated this before I got involved in caravans. But I knew I didn’t know enough.

Look, you can do it all yourself at a weighing station, but the burgeoning popularity of caravanning has also spawned experts who will take the guesswork out of the process.

So that’s where Richard Jarvie comes in. He runs a company called Pull Your Weight and his task is to get your rig legal and balanced properly for the best dynamic outcome.

I first ran across Richard last year when I was doing some towing stories and needed to set up a Mitsubishi Triton with a JB Gator X caravan.

After Richard had finished, the whole thing worked really well and cohesively. I’ve read some stories pretty critical of the dynamic behaviour of the Triton when towing, but our experience was positive.

Now, it was time to get Richard to set up the Kia Tasman X-Pro and MDC Forte SR19 together and see if we can make them work out.

This was the last step in the set-up process before our April 1 departure date. Richard wanted the canopy fitted to the Tasman to ensure its weight was incorporated and that didn’t happen until late March. (We'll talk more about the canopy and other accessories and options fitted to the Tasman another time.)

But Richard had already been furnishing advice throughout the preceding weeks, helping me figure out how to upgrade the Tasman’s towing capabilities that eventually led to a rear suspension upgrade.

So with canopy fitted and leaf springs added it was time to present the combination to Richard for assessment, complete with full water tanks in the van and bbq, a table, two camp chairs and other bits and bobs loaded in the Tasman’s cargo box.

The idea being to weigh the caravan and the car and then the combination as it would be departing our home on the great adventure.

There’s so many aspects to consider. There’s the car’s gross vehicles mass, payload, braked towing capacity, maximum tow ball mass, axle weights and gross combined mass.

On the van side there’s aggregate trailer mass, gross trailer mass, tare weight and tow ball download. Phew.

What do they all mean? Well, go here and you’ll find all the acronyms explained and a practical example of how it all worked out with Richard, the Triton and JB last year.

Richard figures out what’s going via a combination of tech wizardry - digital scales that connect back to a computer system in the back of his Toyota LandCruiser – and his own extensive 'vanning experience.

He charges a modest fee for all this and it takes only a few hours to go through the exercise.

At the end of it you get a detailed report outlining what he’s found (an example of one page is reproduced here), plus practical and helpful guidance on how to improve the set-up.

Richard didn’t mind too much what he saw when I first pulled up, but thought the 'van was too far down at the front.

Some proper measurements and weighing confirmed his first impressions. The angle on the ball was 100mm and the difference in weight loaded on the van’s two axles was too much.

“When you pulled up, you were 100mm down at the front,” Richard explained.

“When you were 100 mils down, there was 500 kilos difference between the two axles on the van. That’s too big a spread.”

The solution? Flip the hitch so it sat 50mm higher. Well, actually, to be technically accurate buy a new hitch because the one that comes with the Tasman towbar can’t be reversed because it has added strengthening underneath.

Hitch flipped and the whole combination sat 50mm closer to level, the axle weights were more even at 248kg more on ther front and the weight on the towball was in the right 8-12 per cent range at 11.2 per cent, or up from 297kg at 100mm down, to 319kg.

Richard said that amount of weight on the towball with the standard Tasman suspension would have caused porpoising, or at least a poor ride and handling because the suspension would be into the tertiary spring/bump stop (conversely, too little weight on the towball triggers sway).

“But you’ve upgraded the suspension by putting extra leaves in it, so we’re not going to have that problem,” explained Richard. “When I looked at it, you’ve still got an inch clearance in that bump stop.”

With our overall combination weight comfortably under the limit (5476kg v 6200kg), the other key measure was the load on the rear axle of the X-Pro. With 2002kg allowed and 1814kg onboard, there was no drama here either.

Assessing all the numbers, Richard delivered his verdict: “I’m happy with that”.

If Richard’s happy, I’m definitely happy. Time to hit the road!

Also read:

THE BIG DASH: Now or never

THE BIG DASH: Why we went Chinese