Thread: GVM minus Tare Weight Equals ?????

the sum aggregate mass you can have applied to the vehicle.

if that comes out at 500kg and you have a 250kg ball weight applied to the tow hitch then you can only put 250kg in the vehicle.

remember downforce weight is NOT the weight of the trailer. just how much weight the tow hitch pushes down with.

Originally Posted by Slater

Hi all and seasons greetings to one & all.

I am buying a 1995 Goldstream Storm off road & am trying to work out the ball weight. All I have is Tare weight=990kgs. & GVM = 1220.

I have contacted Goldstream & been told "from memory approx 150kgs."

Really need to know before I travel 6 1/2 hrs to pick it up. My 1999 Land Rover 300Tdi Defender has 150kgs Ball Weight stamped on the the Hayman Reese towbar plate.

Some years ago, when considering buying a heavier pop top I visited the local Hayman Reese distributor & was given a new plate with 250kg Ball Weight on it.

As I didn't get the pop top I didn't put the new plate on. Now I need to know whether or not I need to...because it is a bit of a hassle to get to & disconnect the dual batteries in the Landy. Particularly if it isn't necessary.

Can anyone help me with this??

Usualy ball weight is 10% of trailer weight.(I like a bit more)
Your van from above...(assuming these are the figures given)
Tare.........990Kgs
GVM........1220Kgs

This allows you to load 230Kgs into the van.
GVM @ 10%= 122Kgs Tow Ball Weight.
GVM @ 12%= 146.4Kgs Tow Ball Weight.

As BKN said, your down weight isn't your total weight.

All these formulae are guestimates. Rule of thumb if you like, which make assumptions about how much of the weight of the trailer is applied to the tow-ball.

Tow-ball weight can be manipulated by the way a trailer is loaded.

• Design of the trailer and how it's weight is balanced.
• How heavy a load item is.
• position of item for or aft of the fulcrum (axle centre)

e.g a 20 kg mass placed over the tow-ball will add 20 Kg to the tow-ball weight. If the mass were placed over the axle it would add zero to the tow-ball weight and placed to the rear of the axle will subtract tow-ball weight.

To answer the question in your title

GVM-tare = payload (or capacity)

Towball weight will be as per Lotz-A-Landies post dependant on the design of the van and the load distribution in the van. I doubt that a van of 1200kgs will have a towball weight of greater than 150 kgs.

You need a set of scales under the coupling to establish towball weight or you need to get onto a weighbridge. Place only the van wheels on the bridge while coupled to your towball, take a reading. Then place the van on a jockey wheel and put the van wheels and jockey wheel onto the bridge. The difference between the two will be your towball weight.

what about braking and a brake controller, i would be more worried about this (not that i ever setup or used the brakes on my pop top) rather than the tow ball weight

I wouldnt be worried about the brake setup. you should be able to tow the trailer without brakes Relying on trailer brakes to help you is a potentially deadly move. Its nice when they work and help out but you dont want to be putting yourself in a situation you cant control if they dont work.

If they have them, work out a way of temporarily disabling them and gingerly try to find the limits of your vehicle somewhere safe and controlled. Its not something you want to find out the hard unexpected way.

It only takes one bad electrical connection to stop the electric brakes, a slipped or snapped cable to stop the generic over run type or a leaking union to stop the hydraulic type.

Originally Posted by weeds

what about braking and a brake controller, i would be more worried about this (not that i ever setup or used the brakes on my pop top) rather than the tow ball weight

Yes I have installed a Tekonsha P3.

Originally Posted by Blknight.aus

I wouldnt be worried about the brake setup. you should be able to tow the trailer without brakes Relying on trailer brakes to help you is a potentially deadly move. Its nice when they work and help out but you dont want to be putting yourself in a situation you cant control if they dont work.

If they have them, work out a way of temporarily disabling them and gingerly try to find the limits of your vehicle somewhere safe and controlled. Its not something you want to find out the hard unexpected way.

It only takes one bad electrical connection to stop the electric brakes, a slipped or snapped cable to stop the generic over run type or a leaking union to stop the hydraulic type.

Point taken but in NSW we are required to have "From 750kg to 2,000kg GTM, efficient brakes are required on at least one axle".

Anyway I have now had further information that the ball weight is 140k.g. So all is now good & we pick her up next Saturday, adjust Tekonsha P3 as needed & see how the 300Tdi Defender goes pulling the 600 or so Kms back.
Based on that I'll decide whether or not to pursue an upgraded intercooler, Dyno Tune or whatever may be needed.