A game of springs
Does one set of suspension really fit all, or is going down the custom route a superior option?
In Issue 31 of RV Daily we looked at what the legalities are for GVM upgrades (still no rock-solid information on the GCM side of things I’m afraid). As we revealed, there are many different options out there for upgrades, but the questions that keep coming up are, do you really need an upgrade, and what compromise needs to be made with suspension components?
We sat down with the folks from Cruisemaster to see what options there are for arguably the most critical components of a towing vehicle: the suspension.
Cruisemaster (nee Vehicle Components) should need no introduction as the leaders in their field of caravan and camper suspension. They build and supply OEM suspension for many top-end campers and caravan manufacturers in Australia; think Zone RV and Kelly Campers. To take things to the next logical level, Cruisemaster are bringing their well earnt expertise in the suspension industry and turning it to the tow vehicle.
What you weigh
If you’ve read our guide on weights and upgrades back in Issue 31 (see link above), chances are you’ve sat down and worked out a ball-park figure of what you weigh. When you’re looking at suspension upgrades, whether you need it for an increased GVM, or you just want to lift your four-wheel drive an inch or two, the amount of weight you’re carrying is a critical piece of information.
If you don’t factor your weights in when you’re looking to upgrade suspension, there’s a very real chance that the suspension components you chose will be more of a hinderance than a help.
The options you have
One thing you’ll not be short of, are suspension options. There are kits on kits on kits on the market, most of which won’t specifically suit what you want to do, or your set-up. This is where knowing your vehicle weight is crucial. When you look at a suspension lift kit, most springs are rated to a specific weight range. For example, 0-300kg variable load, constant 300kg or 400kg weight rating or even bigger. For example on the 400kg constant load springs, you can put an extra 400kg over the rear axle, and the springs will maintain the height and rigidity for which they are designed.
Where this becomes an issue, is if you take the load out of the back of your four-wheel drive (or the caravan off), all of a sudden, it becomes the stiffest, bumpiest ride you’ve ever had. So what do you do? Choosing the right suspension for the job is the next most important item on the list.
Choosing the right suspension
Let’s look at a few examples, of the different requirements for our suspension set-ups.
1: “The dual-cab is usually empty, but we really load it up when we go away.”
With this example, people rush out to get the heaviest load springs they can, because of the twice-yearly trip to their favourite caravan park. Chances are, when you’ve not got the van on the back, it’s going to be the roughest ride you’ve ever had, and you’re not going to be happy with it.
This is where a 0-300kg spring shines. It will happily take the loaded van on the back, but still perform well when the tow vehicle is empty. If you’re nudging the 300kg mark when you’re fully laden, a set of helper airbags can help take up a touch of that slack.
2: “I’m always dragging round the boat or the camper trailer, so it’s always got something on the back!”
Believe it or not, but the same 0-300kg variable springs will work just as well in this scenario. Sure, every weekend you’re away fishing or camping, but you’ve still got to come back to reality for the 9-5 slog. Add to this, your camper-trailer or boat may weigh around a tonne, your ball weight should be 10-percent of that; so only 100kg. Put some fishing or camping gear in, and you’re still nowhere near the 300kg rating. You’re not going to need a GVM upgrade, nor are you going to need those massive 400kg constant load springs.
3: “I’ve got more gear bolted to the four-wheel drive than I know what to do with!” or “All we use the D-Max for is towing duties, we’ve got a corolla for the running around”.
This is where you want to look at constant load springs, and even a GVM upgrade. Rear bars, canopies, drawers, roof-platforms, and the like weigh a fair whack. They also add up pretty quickly, especially so when you throw a caravan behind them. There are kits out there to suit, but the question becomes, which kit, and have you added it all up properly?
Remember: You want to be able to have a compromise between weight carrying capacity, and comfort. The aim is to keep the tow vehicle and drawbar of what you’re towing level. Having a vehicle when you’re unladen level, and its towbar just about scraping the ground when the van is on the back, is not ideal!
The custom route
Spending five minutes in a suspension shop, rattling off what your vehicle and van probably weigh and telling the bloke behind the counter ‘yeah, we’re pretty much always away’, is a very quick way to get the wrong gear. You do, however, have another option. Speaking again with Cruisemaster, going down the custom route is no more expensive than buying a kit off the shelf, except that you’ve got a specialist working out the maths, and putting it all together for you.
Remember that these folks do this stuff day in, day out. From the Remote Area Touring (R.A.T) runs they do (worth a watch on YouTube if you’ve got a moment) to the top-end OEM gear, they’ve got the knowledge and gear to set you up perfectly.
Remember: Even if you have the most well set-up van in the country, and a tow vehicle you’ve not even looked at, the whole package just isn’t going to work. Make sure you’re within your legal weights, but also make sure the way you’re doing it is safe, not with the draw-bar and chains dragging on the ground behind you.