How much higher does this nose weight gauge make the vans hitch when you weigh it compared to when it's hitched on the towball?
Someone calculated on an average 16ft van that 100mm higher reduced a 75kg nose weight by roughly 10kg and conversely increases it by the same amount weighed 100mm lower. In other words the van must be weighed at it's ride height to get the correct nose.weight.
I'm having problems with my new van, I found removing weight from gas locker to arrive at a 75kg ish noseweight rather than weighting the van further back to compensate, made it a lot more stable. I then got as much weight in the car as possible between the axles to keep the car well balanced. This to date has improved things but not been out in decent side winds to really test it. Still did 600 miles in light winds without incident, including bad ruts on the M5.
Shockers I keep being told by those that have fitted them make a lot of difference, enough to convince me to fit them anyway.
PS one other thing I did was remove the chest of draws from the front, this weighed 14kg!!
Quote: Originally posted by arc systems on 18/7/2007
How much higher does this nose weight gauge make the vans hitch when you weigh it compared to when it's hitched on the towball?
Someone calculated on an average 16ft van that 100mm higher reduced a 75kg nose weight by roughly 10kg and conversely increases it by the same amount weighed 100mm lower. In other words the van must be weighed at it's ride height to get the correct nose.weight.
At the risk of being called out - thats total rubbish!
Going back to basic 3rd year physics..... the basics of a lever (which is what we have here) force (ie noseweight in this instance) = distance x mass. Height (unless you go highenough to rule out the earths gravitational pull) has no effect
As a simple test, take said noseweight guage and try it at floor level, hitchlevel and with the van tilted so far back that it almost rests on the rear edge. Failing that does a kid weigh more or less depending on the see-saw being up or down? Even more apt, wind the jockey wheel up or down by 100mm, is it any easier to lift by hand? I bet not.
Now the weight displayed on a weight guage nearer the centre of the van (for example the jockey wheel) will be slightly different from that at the hitch
If the C/G was making 10kg difference over 100mm of vertical at the hitch travel the van is not one I would tow!
Some access roads I drive regularly can result in the hitch being 100mm above or below the level point, heck even telegrah hill on the A30 can probably achieve that easily. A distance of 4m from axle to hitch would give a 1:20 slope a relative vertical movement of 200mm thus according to the quoted calculation a change in load somewhere round the 20kg mark, if not even more, enough to overload a 75kg rated hitch by almost 25%
Nose weight is a static load, once on the move it's dynamic and varies widely, I would suggest this is as far as negative to double or more.
75kg is not much really, if it remained a constant then this starting point could be increased considerable without problem, however it's the potential to increase while on the move by so much that can overload not so much the towbar but thr rear suspension, this will make the outfit unsafe steering wise if not restrained by the lowish starting point.
Any real change in nosewheight, let alone a wide variation means the trailer is not correctly loaded or designed.
A trip in my lightest sprung tow car with the caravan on does NOT have the rear suspension constantly loading and unloading as the downforce on the towball changes due to wide variations in the load placed on it that you claim. This is just as well because at the full 49.5kg load, I only have half a bag of sugar to play with before I am overloading the towbar, I suspect I am not the only one that would be overloading every other change in the road if what you are claiming is correct.
Sorry that you had such a prob getting home. You say you carefully checked the nose weight and it was perfect at 75kg. This is not necessarily all that needs to be done....... How well was your caravan loaded? Let me exagerate by saying, if you had a load of luggage, loungers etc. stowed at the rear of the van and a similar weight at the front then your 'nose weight would be perfect......but your van would be very unstable and would snake at almost anything. Although the noseweight is correct, try to load your van so that everything heavy is right over the wheels and lighter stuff to front and rear. This usually makes for a good stable tow providing your kerbweight is above the total weight of your van.
We are talking here about 'sway' and I'm sure you except 'pitching' as another but this time natural movement of the van while on the move? it has to do that as first the car and then the van go over any bump in the road!
In which case as the van pitches backward the noseweight must reduce and increase as the van pitches forward, it's impossible for it to stay the same.
If the noseweight was as you suggest a constant then what need of a locking mechanism on the hitch?
Hi, If your chassis isn't fitted with shock absorbers as many british vans aren't these would help the stability of the van, Most european vans come with them as standard and I've definately noticed the difference on a van that had them retro fitted as I fitted them to a friends van and it definately didn't roll as much.
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Topic: Caravan Instability.
