Originally Posted by
Kontact
Geometry says this is an unworkable idea. It relies on you getting the fork so perfectly vertical that when you measure down to the table (which must be perfectly horizontal), ....
Table? What table? I guess my shorthand explanation was too shorthand, but I just re-explained it above.
It calls for a string and a ruler (for forks off the bike) and there's no triangulation. Just two easy length measurements, and a simple application of ratios, ie rake/axle to top = measured side/measured short section.
Feel free to knock it, but it might be fairer to actually understand or try it first.
BTW - as far as accuracy goes, it's an analog of the method that surveyors and others have used for well over a century to measure the heights of mtn peaks and buildings.