Snoek Velomobile: Front Derailleur tuning and tricks

Front derailleurs are the most efficient way to get the very wide range of gearing necessary for velomobile use by ordinary mortals. The reason is that we climb much slower than we would on road bikes (I know this well). But we descend much faster than road bikes too (also know this well). So we need an expanded range of gears, but we use regular bike parts. The front derailleur therefore needs to cope with two chainrings of very different sizes (one much larger than what it's designed for).