If you’ve just learnt about tow ball weight, and why its so important you might be looking at a way of measuring your own tow ball weight, and to do this you need a set of tow ball scales, or you can do it at a weighbridge by taking a couple of different measurements.
In actual fact you can do it with normal bathroom scales, or two bathroom scales at home (if you are careful), but most people go down the line of a dedicated set of scales that are designed for the job.
On the cheap end, you can get the spring loaded scales that simply compress as you add more weight, and my folks have been using one for a number of years now. With a Pajero that is capped at 180kg tow ball weight, and towing a 2.75 tonne van they often have to make adjustments to the way their van is loaded to be compliant, and as such it lives in their setup and gets used often.
You can also get hitches with tow ball scales in built, which literally tell you the weight as you drop the trailer on. I’ve not heard too much about the quality and longevity of them especially after lots of hard work, but its a neat idea.
There are also some portable scales that can be used for tow ball weight and wheel weights, but I haven’t heard great things about their accuracy!
Using tow ball scales
If you are going to use scales to measure your tow ball weight, you need to make sure of a couple of things
Load your trailer up as it would be on the road
If you want to measure tow ball weight, you need to do it when the trailer is fully loaded, and ready for travel. That means full water tanks, full pantries and fridges, all of your gear inside and everything ready to rock and roll. Your tow ball weight will change hugely if you don’t do it when its full, and that’s of no help to anyone.
Make sure the scales are at the right height
When you measure your tow ball weight, you need to ensure that the scales make the drawbar of the trailer sit where it would when you are towing. For example, if your tow ball is 350mm off the floor, and you are taking readings of tow ball weight with scales sitting at 450mm, the results are going to be completely incorrect, as the weight changes hugely depending on the height of the drawbar.
Its critical that the trailer and tow vehicle are sitting nice and level, and you should know the hitch heights in order to make this happen.
Take a measurement on a level road
Going on from the above, if you take a measurement on a driveway that is sloping, you will get a different result to what it actually is.
Tow ball weight is hugely important, and if you are looking at ways to measure it well done. Many don’t, and either plead ignorance, or just accept a fine or the consequences when things go badly wrong.
Check that your scales are accurate
A lot of the cheap spring loaded tow ball scales are terribly inaccurate, but there does seem to be some that work pretty well. I’d highly recommend you verify how reliable the reading is before you depend on it, and if its not right, take it back to where you got it and ask for a refund or replacement.