Originally Posted by HarryC

The simplest way is add up weight of all 3 wheels. Divide weight on nosewheel by total of all 3 wheels. That fraction is the fraction forward from main wheels of the distance mains to nose. For example, weight on nosewheel is 1kg, total weight on all 3 wheels is 10kg, distance main to nosewheel is 1metre, then balance point is 1/10 of distance i.e. 10cm forward from main wheels. Couldn't be simpler.