Confusing instructions Alko weighing jockey.

Because our existing jockey was jamming. I purchased the Alko weighing version, which is says is ideal for use with a power mover. I suspect that is what has done for our existing jockey. The instruction book gives details of required calculations to calibrate it. In the equation in the photo below. R is what should show on the jockey wheel display. This is calculated by multiplying the distance from centre of caravan wheel to centre of the tow bar coupling (Ls) by the lowest of maximum tow bar or coupling load,100 kg in our case. This is divided by the distance between the centre of the caravan wheel and centre of the jockey (Lr).

Doing all of the above gives a figure of 125 kg as the optimum value and this given the accuracy of the gauge, is more or less what was showing. I found this a bit odd as I assumed the figure would be less than the tow hook weight not more. However, checking the weight at the hook with the device we normally use gave as usual 90 kg.

I do think they could explain it a bit better, as unless you can also check the hook load, the instructions just lead to confusion, as the figure you are working to is above the tow bar maximum. Surely it would be better if you could adjust the figure on the display so it reflected the tow ball load.