Monthly Archives: June 2013

Travelling through Mud in a Lightweight Off-road Caravan

kimberley off-road caravans blog header off road caravan in the Mud in Northern territory 8480 resized 600What are the traps and tricks approaching mud with confidence with an off-road caravan in tow? When looking at the road ahead which appears to be moguls of mud in a sloppy sea of brown water, your first challenge is to pick a line of travel. Every situation needs to be judged on the ground but without any obvious indications of conditions underfoot, the safest bet is to take the line down the centre of the road. This assumes there are side markers or culvert markers and you can see where the edges are! Narrow Tracking Width of Caravan The wider the caravan, the greater the liklihood that your wheels on one side at least will be off the main track in the side ditches. This spells trouble. The Kimberley Kruiser is only 2.28m wide with the wheels having only a 2m tracking width. This is some 200mm narrower than most caravans and lets you stay on the track a little more easily. Every inch counts! Setting aside the actual road conditions, there are important factors in setting up your off-road caravan to make the challenge much easier. Lowest wheel pressure. Having the absolute lowest wheel/tyre pressure will only help you float accross soft roads. Surprisingly, a tandem off-road caravan can have a lower wheel/tyre pressure than a camper trailer. Lets look at the maths. Now tandem wheels can churn up the ground very quickly with any cornering or turning so these figures are for straight travel. In the example photographed above, the Kimberley Kruiser Black Caviar weighs in at 2750kgs at the Tandem axle. With 4 wheels, theis averages 685 kgs per wheel. Having linked air suspension nicely balances out the load per side. Most camper trailers loaded up are around 1400kgs at the axle and with 2 wheels that is 700kgs per wheel/tyre. Yes, slightly more than the tandem! The ball weight and pressure on the vehicles rear wheels is equally important. In the example above, the ball weight is around 200kgs so for a full size 4WD with around 1300-1400kgs on the rear axle, the wheel/tyre pressure is similar to the off road caravan. Keeping a nice balance of this wheel/tyre pressure between the 4WD and the caravan is invaluable. The key is:
  • low overall caravan weight
  • low ball weight of less than 250kgs
  • air suspension that is coupled
  • matched wheel/tyre ground pressure from vehicle and caravan
  • nice balloon tyres at least 33inch rolling diameter
Tyre Size 33inch rolling diameter tyres are about 5% bigger in rolling diameter to most off road tyres. They hold a higher air volume and can be deflated to lower pressures to really "float" over difficult sloppy conditions. Sometimes you absolutely have to have hard ground underfoot and in these conditions, higher tyre pressures may be desireable. It depends on the exact nature of the ground. Sliding in black mud on the road to Walgett would be a good test of your skills. Brakes You need smooth and softly controlled brakes but far more important is that they are balanced in their control on both sides. Here you will find the superb pleasure of using disc brakes electronically controlled. In muddy and wet conditions, the older style Electric Drum brakes become ineffective as the braking shoes saturate with water and/or mud. Even worse can be the electronic stability controlled systems popular in Europe where nearly all roads are bitumen. These systems need a solid hard surface under foot and are not good "off road". Even disc brakes electronically controlled will give you grief in the mud unless you have a load balancing system to give absolutely even braking performance on both sides. Otherwise pressure on the brake pedal may result in one side braking a little earlier than the other with the resultant road slide that follows. Worst Nightmare can be to turn around After travelling for some time, conditions may deteriorate more than expected and you may just have to turn around and retrace your steps. Arghh! How to turn a 7m tandem fullsize caravan around in the mud! Stability towing off road caravanHaving the ability to do a 90 degree reverse turn has got me out of several tight spots. It's for this reason that we design every Kimberley to have an extended drawbar and narrow neck A frame to the hitch so you can get most 4WD's in at nearly 90 degrees in reverse. The tandem axle could dig its way into a huge hole so only attempt this with some sound ground under the mud. Finally let me give you a even bigger challenge: hidden debris in the mud stakes your tyre and you get a flat! You can, with the air suspension on the Kimberley Kruiser and I'm sure with other caravans (but please check) isolate a specific wheel and lift it up off the ground so you are effectively on 3 wheels. You now have twice the ground pressure on one side which is tricky in the mud. However, if you can travel a short distance to higher ground or cleaner conditions, it will allow you to change the wheel and tyre potentially out of the mud. This is a tricky scenario but it is do-able. Finally remember that road speed has a quadruple effect on the momentum and stability of your rig. If in doubt, halve your speed and keep smiling. We all lose our smile when we feel out of control and that is not the way to enjoy your trip. Experiencing ALL of Australia is just a wonderful experience. I apply the 80/20 rule and generally 20% of the days or the experiences are "average" at best, like driving through the mud! Punching through these "20% moments" is easier with the best technology and well thought out designs for such circumstances. If you are interested in caravan towing stability, have a read of this eBook pictured on the right by clicking on the image. This is a comprehensive guide that covers regular highway travel, particularly at maximum legal speed. There are 14 eBooks and Guides in our serries and one of the other eBooks that is popular is " A design guide to Off road caravans which is more than 40pages". Grab your copy by clicking on the link below. You can find all the Kimberley eBooks in the menu at any of our websites! Enjoy Experiencing ALL of Australia!
Download a 28 page guide on off road caravan suspension design with focus on coil springs and air springs with ride height control
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