You see around the traps people talking 10% of the trailer weight being the amount that should be on the towball.
I think this is an overkill even to the point of being dangerous.
IE: A 1000Kg rig with a towball weight of 100Kg is a crazy setup IMO.

What's the verdict guys?

Fed, here is an extract from the National Caravan and Recreational Towing Guide, I like yourself think that 10% sounds a little light, but if you calculate how much of the weight sits above the axle 10% of the trailer weight at the tow ball means that there is 20% less behind the axle.

PS My new boat only weighs 280kg and 10% is a bit light I think.


Towing Your Trailer
The loaded mass of your trailer must not exceed:

the capacity of the towbar; or
the maximum towing mass specified by the tow vehicle's manufacturer; or
the maximum ball weight specified by the tow vehicle's manufacturer.
The Driver
Apart from adding to the driver's legal responsibilities, towing requires a greater degree of knowledge and skill than normal driving. When towing, you should:

allow for the extra length and width of the trailer when entering traffic;
apply the accelerator, brakes and steering smoothly and gently to avoid sway, especially in wet or slippery conditions;


avoid applying the towing vehicle's brakes if the trailer begins to sway or snake. If the trailer is fitted with brakes that can be operated independently, apply the manual control firmly. Otherwise continue at a steady speed or accelerate slightly until the sway stops;
maintain a space of at least 60 metres between you and the vehicle in front to allow for a longer stopping distance;
engage a lower gear in both manual and automatic vehicles to increase vehicle control and reduce brake strain when travelling downhill;
allow more time and a greater distance in which to overtake. When towing, your vehicle's capacity to accelerate is reduced;
if possible, reverse with a person watching the rear of the trailer;
where areas are provided, pull off the road to allow traffic building up behind you to overtake;
be aware that towing is more stressful than normal driving and is more likely to cause fatigue. Therefore, more rest stops should be planned.

Loading Trailers
It is important not to overload your trailer. You should not exceed the maximum load specified or recommended by the trailer manufacturer, nor should you exceed the tyre or coupling capacity. Trailers now have attached to their drawbars a plate displaying the ATM which is the maximum allowable weight.

As a general rule, the ball mass (the mass towards the front of the trailer carried by the tow ball of the towing vehicle) should be about 10 % of the total laden trailer weight. The ball mass can be measured either at a weighbridge by resting only the jockey wheel on the scale, or by placing a ball mass scale under the coupling then taking the weight off the jockey wheel

I'm just the opposite to you Sumo, I think 10% is way too heavy.

Fed I generally find that if I can lift a single axle trailer drawbar without exerting myself and put it on the ball it is about right. But I have never weighed it to see what percentage of the total weight it is.

Another Point, If I was towing a 2000kg trailer I don't think that I would want 200kg pushing down on the tow ball.

Yep, about 100lbs (45Kgs) is a reasonable weight for an average 15-16-17ft trailer boat, a little more for heavier boats and a little less for lighter boats.
It's the 10% that gets talked of that worries me.
A 1000Kg (smallish boat) with a towball weight of 100Kg would be unliftable for most people.

I think this is a typical example of how Percentages are used incorrectly,
another couple of examples are when the Government gives everyone a Pay Rise 10% of the politicians pay is a massive amount, whereas 10% of a pensioner's is a pittance and if you are self employed Who the hell is going to give you 10% when you are paying more for the Politicians.

and have you ever noticed the big stores give 60% OFF specials, off what did they jack up the starting price, or have they been ripping everyone off for yonks.

Towball MAX down rate is started by the manufacturer, and you should not exceed that.

More weight down on the back affects the handling and the brake of the veichle, unless your in a 4x4 fitted with a brake proportioning system, which adjusts the braking of the veicle to suit how the veicle is sitting on the road (If the back is sitting low with weight, the braking dynamics of the veichle will change)

To add to this, the weight on the tow ball is also added to your veicle mass, meaning if you have a full car and load then you may be overloading your veicle, so check the specs out for your specific veicle.

Did you say 100Kgs Fed ?????????????????

My towball weighs nothing near that weight in fact I can easily hold it in my hand & let me tell ewe dont think it would even make the kilo mark

Seriously though I think more emphasis should be put on the tow vehicle than tow ball weight they can throw as many figure as they like @ you which I might add the majority of peeps would not have a clue about including myself I have no idea what the towball weight is on either of my trailers.

All I know is that I set up the car to handle towing just about anything

Has anyone ever experienced the 'sways', that stuff's not for the feint hearted.

Not with any of my current boats as they're setup correctly moreso cause my tow vehicle is set up correctly

One good way of copping the sways is bad suspension weight of boat will rock the car from side to side & it dosen't need much to start the mition

Did cop a mittle bit of a scare about 6 months back coming home from Greenwell Pt silly me allowed that Goose CATCH22 to secure the strap over the little boat well the goose didn't 1/2 hitch the loose end of the strap it came loose wheel ran over it somehow & I was swaying.

If you need to do some special setup on your tow vehicle then you have an underlying problem with your trailer providing your tow vehicle is rated to tow the load.
The trouble with the sways is that they don't show their ugly head until you're doing 100 KPH down a hill on the freeway and then things start happening very quickly.

i can't say i agree with u fed, to set your vehicle up in a way that allows u to tow more than one trailer is not such a bad thing, a set of air bags under the springs will allow u to adjust the attitude of the tow vehicle, i will refer u back to rum dust n ruckus's post he can explain it better than me

Poly, some cars and 4x4s have a brake proporsioning/load sensing system, which when weight is placed on the rear of veicle s lever or cable operated mechanisim changed the bias of the braking system, transfering more braking to the front or rear of the car as required.

Hilux's are an obvios one as the mechanisim is located on the rear diff and can be seen.

Most importantly adjust your driving accordingly..

There's no logic in altering a car to overcome a problem with a trailer.

Sumo, is your whole rig only 280Kgs or are you only talking about the hull?

Double post so I'll say something different.

Are we having fun yet?

Fed, my boat and motor combination weighs 280kg's . My Dunbier trailer according to my rego papers is 150kg which I think is a bit high I would rate it at about 120 but this DOES include wheels, tyres, hubs axles and springs which make up the majority of that weight which is NOT a carried weight on the trailer but the actual carraige that carries the weight and is at no time a part of the downward weight on the Tow Ball.

The biggest Towing factor with my new boat is the Height of the bow which is about 6ft to the top and this boat although very light has a tremendous wind drag, Now how do we relate wind drag to Tow Ball Ratings does it become Wind x Speed calculated by 10% or is it like W = S over TB ( thought I'd just throw that one in for you Fed)
You might understand I = E over R in our trade.

Why is it so high Sumo?

Just the way it was designed Fed , with a high casting deck up front.




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Tow vehicle has everything to do with it.

No different to a performance hard ride but the car handles.

You tow with a vehicle with soft shocks or crappy springs & thats where your swaying starts

Weight of the trailer shifting it's weight from one side of the cats suspension to the other hence your swaying

i tow with a mini is that too small jumpas my boats only 21 fta ...please explain ..master goose ...

A standard car with standard suspension should be able to tow a correctly set up trailer without having to tweak the car suspension at all.
If it sways then the problem is with the trailer set up and that's what should be addressed.

Dont think so Fed suspension wears down & alot quicker if you're towing for peace of mind peeps should not be tight arses & invest some $$$'s teaking up their suspension.

Most of the time time it's not even the tow vehicle thats @ fault but other gooses on the road nearly causing accidents.

I'm always confident that I can pull up my rig in a dead straight line if I have to hit the brakes in a hurry that means no swaying

Speaking of Gooses !

I see that CATCH22 has dropped in 4 a gander

Same goose who left a loose strap dangling also didn't secure the shackle to the boat after he was told just clipped on the winch hook & turned handle a couple of times after I drove boat on.

I blew the crap out of STEVE for that cause I'd 4gorren Dave had come out previous trip only noticed when checking to go out next & there was a very very good chance I would've losrt my boat off the traler cause the hook on the winch was neary dead straight.

So a worfd of warning dont tell Dave where you guys live & dont let him anywhere near your boats

Don't worry Dave, You're welcome back at my place any time, and from whichever direction you wish to travel,

Don't let that Jumpy scare you even if it is Dark in there. he doesn't own the confessional.

And by the way, My Boat is My Responsibility regardless of who TIES it on.

Good call Sumo, we'll drag him out of Jumpy World sooner or later.