Stabilising bars on caravans

That’s not real smart Batts.
Read 671’s post below it may help you understand the theory behind it all.

I am well aware of what this particular towing aid has been designed for I use to sell them yrs ago. Not sure what you mean by not real smart what part of what I said is not real smart. All I said was you can safely tow without them as I said before some people are under the impression that you can't because they have been convinced by someone that they should not tow without them, they are a must have item this is not true. Some people who purchase these through my experience have absolutely no concept of what they are doing when it comes to towing ,setting up suspension on a vehicle ,van, trailer etc and how to load their gear correctly due to lack of knowledge or just pure ignorance that is a fact which you see examples of quite often when you go for a drive. So the quickest fix is for someone to recommend a towing aid which is quite often incorrectly used to compensate for a poor vehicle set up then they spend the rest of their years not knowing any better this does not relate to everyone by the way. Some people have researched this product and know how to use it correctly if it is required for their set up. Then you get the die hards that just will not be convinced that it is safe to tow without them and believe they are protected by an invisible field because of their WDH.

"Just get rid of them if your tow vehicle and van are both set up correctly with the right springs, shocks "
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Batt

Cars come from the factory with the right springs and shocks to do whatever they have been designed to do. There are a lot of vans and trailers that my car can tow without a WDH because their ball weight is below the factory limit for no hitch. As I said before though, if I exceed that limit I must use a hitch. That is because somebody did convince me as you suggested but that somebody was the car manufacturer. When the day comes when I know more than the factory engineers, I will ignore their instructions and use your method of setting it up properly with the right springs and shocks.

By the way, could you lease explain how aftermarket springs and shocks can take a portion of the ball weight off the rear of a car and transfer it to the front? If you already know they can't then why is it ok to drive around with an excessive amount or weight hanging off the back

All ball weight is sitting on the end of a lever i.e. the distance from the rear axle to the tow ball. You only have to try a simple experiment with an axe to see what it is doing to the back of the car.

Hold the axe by the head with the handle out in front of you in a horizontal position. You will find it is easy as one would expect because it only weighs about 2 kilos. Now hold the end of the handle and try and keep it horizontal. You will be struggling yet you are still holding only 2 kilos. The only difference is you have moved the greater part of the material in the axe i.e the head, a lot further out from your hand and the laws of leverage have taken over.

That is what is happening to the back of your car while towing. Imagine the maximum weight of 350 kgs on a Landcuiser for example. The leverage effect would be massive but it would be far worse when the rear wheels drop into a depression in the road and all of that weight comes crashing down only to have the end of the car catch it and heave it back up instantly when the wheels come up again a split second later. That is what causes so much chassis, axle housing and wheel stud damage in the bush. No wonder the manufacturers say a portion of the weight must be taken off the back wheels and moved froward to the front wheels. Heavier springs can not do that.

Stabiliser bars are only going to be effective if they are set correctly. I can tell you from experience that many people do not set them correctly because of the amount of energy required to do so, so they set them with very little tension and as a result are under a fasle sense of security.
I agree, if a vehicle is set up correctly to compliment the towed vehicle you wouldn't have a need for them.
Enjoy the journey

Thankyou Munji at least someone else knows better....671 Your totally wrong about cars coming with the correct springs out of the factory to do the job some have done it correctly but most haven't. Try loading most cars up to their gvm before you even look at towing and you'll find the rear end will sag and the car will be unstable. These days most vehicles are set up with a comfortable ride being the most important factor they want their 4WD to ride like a car which helps to boost sales that's a fact so they have soft springs and shocks so if you want to tow a WDH is a necessity to help stabilise the ride. If they had the correct suspension to cope with what their maximum capabilities sales would drop and more people would winge about having and uncomfortable ride in their already top heavy 4WD which they expect should handle ,ride and have the same or better fuel economy than a car that is also a fact. Of course after market can't transfer weight to the front because you don't need to why are people so obsessed with this weight transfer it is totally safe to tow without a WDH if you have the correct set up that is all I am trying to say. Obviously you have always had one and have never had the knowledge of ability of knowing how to set up a vehicle and tow safely without a WDH you have a lot to learn try stepping outside the box some time you'll be amazed ende.

Batt

You have made a lot of claims without any engineering facts to back them up.

1. "Try loading most cars up to their gvm before you even look at towing and you'll find the rear end will sag and the car will be unstable.."

That depends on how you load it. Take a Cruiser wagon for example. They are a five seater estate car that will carry about 650 kgs. If you put a 60 kg driver in it then fill the fuel tank, you will have about 140 kgs. Next put the remaining 510 kgs behind the back seats and see what happens. Of course the back will be dragging on the ground. Is that the fault of the manufacturer's soft suspension or the idiot loading it?

Now try a different approach. Put five decent size adults in the seats then fill the tank and add the rest to the back to bring it up to GVM. Don't be surprised if it is now sitting up nice and level as the manufactured intended.

If an owner can't get enough weight into the cabin, particularly in a dual cab ute, then you can't get it up to GVM without taking it outside its design limits. You simply can't load a car anyway you want to.

If you want to tow something then you should know the tow ball weight must be deducted from the car's carrying capacity. The maximum of 350 kgs on the tow ball of our example Cruiser would leave 300kg that can be added to the car. The fuel would take about 80. That leaves 220 kg for a family or a few adults. There are plenty of young families with children who would have a combined weight of no more than 220.

The rear would still be sagging so the final step is to lift it with a WHD and move some of that ball weight forward to the front wheels. Once again the car should be level as it was designed to be when correctly loaded.

2. " why are people so obsessed with this weight transfe"

As I have said before, the manufacturers of many cars say it must be done for ball weights above a certain amount. It is not necessary below those limits. I would suggest you ring a few manufacturers and tell them it is not necessary. Better still, try studying suspension design, the leverage effect of weight suspended so far back behind
the rear axle, the dynamics of what happens when all of that mass (the amount of material in something) is put into motion when it is bouncing up and down on uneven road surfaces and side to side weight transfer in corners and you will understand and won't have to ring them.

You're wasting your breath 671 – “There Are None So Blind as Those Who Will Not See”

As Batts said

" if your tow vehicle and van are both set up correctly with the right springs, shocks and is sitting level when connected together which is very very important, your van has been loaded correctly and your brake controller is adjusted properly there is no reason for you to have them fitted at all."

If the vehicle is level it is loaded properly, why is there the need to transfer weight to the front Wheels? All the WDH does distrubutes weight (WDH!!)

while everyone else is also correct in their statements you are all not addressing the point made by Batts.

Alan

Thank You Alan I didn't think it was that difficult to understand I think I'll leave it there.

To Allan.

You can make a rig sit level if you pump up air bags but it will still be light at the front.

The correct way to hook up is to measure your height on the vehicle to under mudguard front and back.

Then hook your van on and measure again.

It wont be the same or even to what it was.

Thats why we use a WDH

Quote
If the vehicle is level it is loaded properly, why is there the need to transfer weight to the front Wheels? All the WDH does distrubutes weight (WDH!!)

Thats what its for isnt it.

Look at it this way You have a seesaw sitting level you sit on one end and what happens. It drops at that end so to get it level you have to add weight to other end. That is a rough description of what a WDH does.
By the act of the ballweight it drops the rear of the vehicle by swiveling on the pivot point which in this case is the rear axle. so how do you drop the front to what it was.
Several solutions

Fix a block of concrete to front bumper after hooking up.

Attach a skyhook to A frame to lift it or fit a WDH.
Adding airbags to lift the rear does just that and all they do is lift the pivot point higher and the negative amount of weight on the front end is not altered.

This has been done to death over the years and there will always be the sensible ones who use them and the others.

A very light van possibly wont need them if loaded correctly but anything over 1500kg will usually benefit from the use of one.

Especially the diehard that lived near me who wouldnt use one.

He had a 7M Coromal loaded to the gunwales towed by a 3L Patrol auto and when he drove towards us you could see over the top of his front axle. He also used to put split rims on it when towing with skinnys on them.
Wouldnt like to have driven that on a wet road.

But no he didnt need a WDH and didnt care his vehicle was towing well over its legal capacity.

TomH

I fully understand what you are saying in regard to the WDH where the rear end sits low.
But as Batts has said with the load on the vehicle sits level. So what i am asking is why if the Vehicle is sitting level "correctly with the right springs and shockies" is a WDH needed?

Now I am no physicist but i also believed that when a vehicles level was altered from level, some of the weight is transferred from the higher to the lower wheel. i.e raise the rear suspension without changing any other weights takes weight from the rear and puts it on the front wheels.

So using a WDH on level vehcile will take more weight off and make it sit even higher.

On heavy vans where the vehcile manufacturer recommend the use it is a given especially as dont think you will find many cars sitting level with them anyway. But on light vans where in the case put foward the only benefit i can see is that the stiffer connection will probably aid stability of the van.


Alan

"some of the weight is transferred from the higher to the lower wheel. i.e raise the rear suspension without changing any other weights takes weight from the rear and puts it on the front wheels."

It does not work that way Alan. The confusion between springs and a WDH usually comes from people thinking both of them are springs. A WDH is not a spring, it is a lever. You lift them up and hook them onto the van draw bar but if it was possible to keep lifting them you would eventually lift all the weight off the rear axle and even lift it off the ground if you kept going. Heavier springs can hold the chassis up a little higher but they can't take weight off the axle or transfer it anywhere.

The real problem here is not so much how the car looks but what happens to the weight on the tow ball when the car is moving. Most cars have their tow ball about 1 to 1.2 metres behind the axle. That is a hell of a long lever. If you put the weight over the axle, the springs will compress a little. If you put it a metre or more back, they will really go down and the front will go up. The down forces exerted on the end of the chassis will increase by the square of the distance the ball is from the axle. These forces will become even higher when the car is in motion.

This is why so many people have thought their car was set up properly at home with their new springs and shocks only to bend their chassis, crack a diff housing or sheer wheel studs when the car was in motion out in the bush.

It is also the reason why car manufacturers want a portion of the ball weight taken off the back and moved forward to the front if it is over a specified limit.

I agree. Put the bars on whilst the car is still on the jockey wheel. If it's still a bit of a lift, jack the jockey wheel up until you can clip the bars on. Same when taking them off. Easy and works a treat.

cheers
Laurie

I can't believe there are people out their still towing caravans without WDH . With all the information available out there about the dangers to the contrary . And on top of that trying to convince other people who know better thar WDH are not necessary.GHU.

If you had a look at his profile then you would see he does not live in RAC country.

Linny, check with your motoring organisation (if you are a member) regarding upgrading your membership to cover towing vans. NRMA have two levels of cover above the basic membership that cover different sizes of vans. Those premium memberships cover things like towing the van if anything happens to it or your tug breaks down.

Would you really waste membership money asking RAC to come out and change a wheel, fare dinkum.