Trailer nose loading

P

pcatterall

Well-Known Member
Joined
2 Aug 2004
Messages
5,507
Location
Home East Lancashire boat Spain
Visit site
Fingers crossed, I may have at last got me a trailer sailer. I was able to see this one out of the water and the seller will take cash on collection.( Thanks for your contributions to my thread on ebay sales)
It sits on a 4 wheeled trailer ( thanks, again, for your contributions to my 2 versus 4 wheeled trailer thread!)
I noticed that the weight on the hitch seemed excessive ( I couldn't raise it and I know I can lift 200lbs) I will be towing with my 3500kg Transit and will investigate this aspect further but any advice welcome on that.
If I want to redistribute the load is it possible to move the boat back now she (1300kgs) is on the trailer? The outboard is still on and I plan to remove this for towing but that will only make tha balance worse. Can I jack or lever the whole boat back by levering against the bilge keels or will I break something? (My back?)
Thanks, as always for your advice.
 
Optimum nose weight for a trailer is around 70kgs. Over loading the hitch can cause stability problems, but not as much as not having enough weight there. Negative noseweight can make the outfit almost unmanageable at any reasonable speed. A great deal of it depends on the way it is all set up, how the weight is distributed on the trailer, softness or otherwise of the tyres, etc. 4 wheel trailers are usually much less prone to handling problems as the axle configuration makes them inherently more stable.

Excessive mass at the extremities, even if the trailer is in balance can cause bad handling problems. A large outboard hiung on the back for example can cause the trailer to start snaking much sooner than if the mass is placed near the middle for example.

It is usually possible to move a small boat (up to a ton or so) on a trailer. If the bilge keels are metal castings or steel plate, there is usually no danger of damage. If they are GRP then the pressure has to be spread to avoid point loading and crushing the moulding. The safest way is to support the hull independently of the trailer in such a way that it can be jacked up sufficiently to be able to move the trailer. Usually only six inches or so lift is required.

You may be able to lever the boat back, but this is unlikely if you have to move it any distance, and there is distinct risk of damaging the keels at the point of leverage. Might be worth a try though with suitable padding.

A quicker, cruder and less safe way is to pass a rope round the bilge keels back to a tree, hook up the tow vehicle and edge forward until the boat slides back on the trailer. Dont use nylon as it will stretch and could bounce the boat off altogether! I have done this with an 18 footer. A safer variation is to use a tirfor type winch attached round the keels and have the trailer well secured. Easier that way to control the movement. I have done it succesfully both ways!

The 'proper' way is to hire a lorry with a HIAB arm, usually around £50 for a small job, then you can be sure the boat is properly balanced by repositioning until its right..
 
Last edited:
The maximum nose weight for your vehicle should be in the handbook and as suggested getting it wrong can have a real impacty on handling, not nice.

When I had a bilge keel boat I used to move it up and down the trailer with one of the 2 inch ratchet straps used for securing it to the trailer. You can get cheap and effective nose weight measuring devices at any caravan shop.

With my present cat I have about 75 Kg noseweight but may previous one was happier just over 50. If you want real flashy you can get jockey wheels with a balance built in.
 
Thanks for those tips. I see that an 'official recommendation' is 7% of the gross trailer weight indicating around 110kgs on my hitch. I still can't find the recommended nose loading for my van. I have also seen the max 70kg figure but wonder if this is really for cars?
 
pcatterall said:
Thanks for those tips. I see that an 'official recommendation' is 7% of the gross trailer weight indicating around 110kgs on my hitch. I still can't find the recommended nose loading for my van. I have also seen the max 70kg figure but wonder if this is really for cars?
Click to expand...

Neither is true, every vehicle has it's own limit so you need to find that out, too light and the nose of the trailer will tend to lift the back end of the tow vehicle and swing it about, too heavy and the stearing will become light and impresise and the tail will be wagging the dog..

Most vehicles are designed to carry most of their payload between the front and rear axles excess weight outside this area changes the designed balance.

It seems if you find the towbar for your van on this site they specify the nose weight

http://www.towequipe.co.uk/Homepage.html
 
I think the best gauge of nose weight is to check that the trailer chassis and the vehicle chassis are more or less in line when hitched up. If the trailer is pushing down hard on the vehicle rear suspension so that the tow vehicle sits back, while the trailer sits forward - then the probability is that there is too much noseweight. And vice versa - if the trailer is lifting the rear suspension of the vehicle when hooked up, then the rear wheels will not grip so well, with implications for handling at speed on bends etc.
 
I have had success moving a bilge keel boat on a 4 wheel trailer to a better balance point.
Assuming you have a bow post with a winch, slack off the winch strop about a foot or so (depends how much you think it needs to move).
Run some water on the keel pads on the trailer. Reverse up and brake violently. The boat will (should) move back a bit. You probably need to do it far more violently than you imagine, but start gently.
I've done it with a few boats and it is surprisingly precise.
If they are steel keels, a crow-bar will jiggle it back a couple of inches at a time on alternate keels.
Nose weight is deceptive on a four wheel trailer. What you really need is the hitch and tow-ball to be at similar levels. If you try lifting the hitch you are moving the fulcrum toward the rear pair of wheels.
Ask Duncan Mack
 
With a 4 wheel trailer you can't lift the nose like you can with a 2 wheeled one. Although you try and lift it you can't really judge the weight as the 4 wheel loads will vary as you lift. The proper way is to measure it with the tow hitch at the correct level (bathroom scales?), the simple way as was suggested is to couple it up and make sure the setup is reasonably level. stand on the drawbar to make sure there is suspension travel left.
 
Its worth getting the hitch weight right.
I use an axle stand and old bathroom scales.
If you dont have this, and you weigh abot 70kgs then this method sort opf works....
lean a stick up againt the hitch and mark the top with a pencil. Jump in the back and mark it again and note the drop. When you hitch up the boat look for a similar drop when the weight comes on.
My Hiace is great with 75 to 100kgs.
Discoveries will take up to 150kgs.
 
gordmac said:
With a 4 wheel trailer you can't lift the nose like you can with a 2 wheeled one. Although you try and lift it you can't really judge the weight as the 4 wheel loads will vary as you lift.
Click to expand...

Agreed. With two axles, the trailer is just going to sit where it wants regardless of anything else. The nose load will be dependent on the relative heights of the ball and hitch and the stiffness of the suspension on both the towcar and trailer. That's just on a flat surface. Over undulations, it will feel like the trailer is trying to wrench the whole towbar off the car. I had 4 wheel trailer for a while, and hated it.
 
The general rule of thumb we use in Australia is the ball weight should be 10% of the overall weight. Less than this can result in stability problems. The tow vehicle must be able to cope (and be rated) with this ball weight or it is not suitable to tow the trailer.
For larger trailers we use a weight distribution hitch, which allows for a high ball weight, transferring some of this weight to front axle, airbag assisted rear springs are also used.
Large boats towed long distances over rough roads are common. I used to own a 25 foot yacht with an all up weight of 2700kg. I towed it every June 5200Km (2600 Km each way, done usually in 2 days) for my annual holidays.
 
Last edited:
The best and safest way is to use a "Spanish Windlass". Get a good sized rope,tie into a loop one end round the bilge keels the other round part of the trailer.Protect the rope with rags etc then wind the rope up by twisting with a bar,this winds the rope up like spring and will move a heavy load.Have moved a Seamaster 30 on a trailer with this method.
 
Nose weight on trailer

I would be very wary of the rule of thumb of having the draw bar and towing vehicle in straight line. You don't know if the draw bar is naturally high or low and the tow hitch high or low. I am not experienced with 4 wheel trailers however logically a level trailer means equal load on each axle hence a load on the draw bar representing the position of the boat.
I certainly know that a light draw bar load on 2 wheeler gives horrible handling especially when going down a hill (decelerating) at speed the trailer will start to sway and the only way to stop it is to accelerate.
Obviously an excess weight on the tow ball will remove the weight from the towing car front wheels reducing braking ability and pointing headlights up too high. I doubt this will be a problem with a commercial vehicle like a transit compared to a passenger car.
I had an old car with leaf springs at the back. I got a set of helper springs which really worked well. One bolt on each side would increase spring tension to lift the back of the car. Later I got a car with coil springs so I fitted so called leveller bars. here a big casting is fitted under the tow ball. Spring steel bars about 1 metre long go into this casting with a right angled bend so they extend parallel to the draw bar. The ends are pulled up to the draw bar by chains. The end effect is to try to tip the towing car nose down or lift the back of the car. This leveled the car while retaining a high tow ball load.

However to the OP I suspect you will find the balance OK is if you can't lift it but the towing vehicle doesn't look too down at the back.
good luck with the new boat. i suspect you need rollers under the bilge keels to make winching on in shallow water easier/possible. olewill
 
TQA said:
It is a 4 wheel trailor and a TRANSIT !

Assuming it is a proper tow bar and not a bit of angle iron bolted across the bumper mounts there should not be a problem even if the nose weight is on the high side.

You could add a drop plate to lower the tow ball a bit if you were concerned.
Click to expand...

you are only allowed to lower the tow ball with a drop bar, and that isnt going to reduce the weight on it, is it ?
Its not just about the weight on the hitch- that in itself is indicative of the trailer balance abnd more specifically the weight on each axle. You dont want to overload either axle., or get caught doing so.
I dont know the trailer set up, but its usually possible to move the winch bar backwards, which might then help load the boat more evenly across both axles, and so reduce the weight on the nose.
 
Thanks for the further contributions. I cant find the max nose weight for my transit in the handbook but will scour all the plates on the vehicle to try to find it.
TQAs idea of a drop bar/plate sounds technically ok ( but I am the novice!)
It would reduce the weight on the nose but of course we dont want to do this if it would adversly affect the balance of the boat on the trailer.
 
gjgm said:
you are only allowed to lower the tow ball with a drop bar, and that isnt going to reduce the weight on it, is it ?
Click to expand...

Yes. It's a close-coupled trailer and as you lift the hitch the fulcrum is moved to the rear axle, relieving the front axle of load and consequentially loading the hitch with some of the weight the front axle is not supporting.
 
You must log in or register to reply here.

Other threads that may be of interest

O
South Coast - Cheap boating option
3 4 5
Replies
93
Views
2K
Chiara’s slave
Chiara’s slave
R
convert laptop to chart plotter
2
Replies
26
Views
875
MontyMariner
MontyMariner

Share this page

Top