One good reason not to do this is because when the bow wave of an overtaking vehicle hits a caravan it obviously meets the back end first, so it tends to push the back end to one side - the caravan pivots on its central axle(s) so the back end move in and the front end moves out.
The towcar will then dampen that initial movement - ie the opposite movement happens - the back end moves out and front end moves in. But - just as the front end begins its inward movement the bow wave from the overtaking vehicle hits the front end, thereby adding to the inward movement, so the sway is amplified. That is why a succession of overtaking trucks or coaches can lead to greater problems.
The towcar has to dampen that sway - at which point it is worth looking at the caravan as a pendulum. If the weight is at the extemities (front or rear ends) then the moving mass the towcar has to control is much greater. Hence the sway is harder to control.
Which is a long winded way of saying why weight should be kept as close to the axle as possible rather than at either end. You need the right noseweight - but don't do this by adding weight right at the front end.
The way you load your van to acheive the desired nosewight is also important. In particular, avoid putting heavy things right at the back as this creates a 'pendulum effect' which causes the kind of instability you describe.
Do an internet search for 'caravan loading' and you will get full information.
Our caravan has a rear kitchen and a couple of gas bottles and a spare wheel in the front locker and do as suggested above with loading the caravan with the vast majority of weight over the axle.
dianne poxon
Do you load the caravan up with every thing or do you put it all in the pickup. loading the caravan upto its max weight will lesson the drag toward the lorrys. But make sure there is some weight in the back of the pickup because there very lite at there back ends.
Sorry, I hadn't realised it was a pickup. That does make a difference. Just like a van, you do need some weight in the back. Many years ago, I used to tow quite large trailers with a J4 van. It always needed a couple of hundredweight bags of cement over the axle, before you could tow comfortably.
Don't go right up to the maximum caravan loading, in case you have made a mistake and go over. But don't tow it lighter than you can help.
Do put some weight in the back of the pickup. Probably about 50-100Kg. If you're not carrying anything, get a couple of bags of sand.
i had simular problems.due to towing vehicle being a transit type sied minibus ( a van with seats) i had very little in my van and caravan and caused me so much stress i didnt want to tow back but now i have nose weights and plenty of gear in both tow and towed vehicle.
all my heavy gear is on floor from axle to front inbetween seats and lighter stuff is at rear of van,once i got it right its now a pleasure to tow.
Today has been a foul day in Scotland. Gale force winds, and heavy ran. Caravan has towed like a dream. No sway when passing artics coming in opposite direction, no buffeting from headwinds or side winds, brilliant.
OK its a pop-up, but the other factor is the tyres. Changed these for C rated tyres at the start of the year and they have made quite a difference to the way the caravan tows. Now on the motorway at a steady 60, there is no sway at all when a bus comes thubdering past.
If there is a lot of sway think about changing to stiffer tyres.
Just a thought, how high is your towball? does your van sit with a slightly nose down attitude when it is hitched up or is it raised up with you having a pick up?
I have a height adjustable dixon bate towbar on my discovery and if I put it just one Inch higher than the setting that I normally use I find it makes a hell of a difference to how the van behaves when on the motorway, even though the actual nose weight of the van is just the same in both cases.
jel2006 Your spot on. When there running to high the wind gets under the front of the caravan & makes them rock about. It makes them feel very unstable.