Trailer Ep16 - tow ball weight

The trailer needed to be balanced with the correct "ball weight". The weight on the tow ball is critical for safe towing and needs to be around 10% of the total trailer and boat weight. (sources - RACQ, Toyota truck manual, local mechanic and online forums) Trailer boat and gear's total weight (ATM = Aggregate Trailer Mass) is 1,200kg (found on my registration certificate).

So adjusted the trailer so the ball weight to around 10% of ATM, 115 kg, by moving the main axle back and the winch post forward. Both of these fixtures are clamped on by U-bolts so can be moved as needed. Correct ball weight eliminates "hobby-horsing" of the tow car and potential jack-knifing of the whole rig when braking hard.

I measured my ball weight with bathroom scales,  protected by wood. A piece of 4x2" timber cut to length went between scales and tow cup to take the load. The tow cup was raised and lowered with the jockey wheel.

Measuring tow-ball weight

The outboard's weight isn't included as it is always removed for transporting.