Reply With Quote[QUOTE=Rosscoe68;1240274]i have towed in many various guises and it astounds me that anyone can think a loaded badly van tows better with a WDH than a correctly loaded van without WDH.
Rosscoe, with respect, I don't think that anyone is saying that. What those who actually have experience towing caravans with and without WDH (and Harlie is right: it is obvious to real caravaners who does and does not have that experience) are saying is that WDH will improve handling and braking, and therefore safety, for the tug and other traffic, particularly with larger vans. From my personal experience with a range of vans up to 21 ft behind my D2, on and off the bitumen, that is a no-brainer. It should go without saying that proper loading of the van is critical regardless of whether or not a WDH is used. Despite the claim that it is an urban myth, that also applies to the international "rule of thumb" that the weight on the tow ball should be around 7 to 12 per cent of the total mass of the van (for simplicity let's call it the 10% rule). Good vans are designed to provide this sort of weight distribution with proper loading, i.e. with tanks full and most of the remaining movable mass close to the axles.
That much is very easy to prove, either with an experimental rig as with the Bath University studies, or in practice with a real van. Just take a spare pair of undies if you try the no weight on the towball idea and go above 30 to 40 kph with a typical van.
It is also unwise to generalise statements about the design of caravans, which range from (for example) 13 feet long with a single axle to 30 feet long with three axles, which may be low mounted for bitumen work, or high mounted for dirt road or off road use, which may be on sophisticated independent suspension or on simple leaf springs with beam axles. Above all, they may be built by a properly set up, experienced and competent builder, or by an under capitalsed, inexperienced "johnny come lately". To suggest that Bushtracker, Kedron, Phoenix and similar vans are made just to look good and not to tow well does nothing for the argument because it is so obviously wrong. As with vehicles, there are some vans which are less than ideally designed and some which are not properly loaded.
It is not necessarily correct to extrapolate (too far) experience towing cars or boats to towing vans. There are substantial differences caused by the keel area and weight distribution, which may significantly affect the dynamics of towing.
It has been suggested that Land Rover's D2 tow rating of 3,500 kg with 250 kg on the ball demonstrates that Land Rover does not believe in the "10%" on the tow ball rule, or has somehow screwed up. That isn't a valid argument. It just means that Land Rover engineers have certified the chassis, towbar, suspension and brakes to tow a horizontal weight (e.g. a 4 wheel trailer or another vehicle on its own wheels) of up to 3,500 kg, or to carry a vertical (static) weight of up to 250 kg on the tow ball. The 250 kg vertical limit in practice probably limits safe van weight to somewhere between 2.5 and 3 tonnes.
This is a great forum, and everyone should feel free to express a view, but the problem is that there are probably newcomers to caravaning on here who are looking for safe and practical advice. Sadly, some of the views on this and similar threads here and on other forums are potentially dangerous. Anyone is entitled to disagree with the international "10%" rule or the supposed benefits of WDH, but for the sake of the newcomers to caravaning in particular, but also to those of us with such experience, please provide some sort of supporting evidence or a rational argument to support your counter view. None of us knows so much that we can't learn more.
Originally Posted by StephenF10
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