Well on this weight discussion a crucial point is overlooked: any normal bike has a front hub. And those range between 170 and 250 grams (100 mm axle for quick release), depending on the amount of money spent.
Weights for the most important dyno hubs (all as 100mm axle versions):
SON 490 g
Shimanos LX equivalents at 550 g, the xt version is at 480g
SP Dynamos (8 Series) 400 g
SONdelux: 390 g
SP 9 series: 310 g
The latter two i wouldn't use if one wants to generate a lot of power, as they have less magnets so they generate at lower speeds less power. For any modern LED light still totally sufficient.
So the
weight penalty for a (normal) hub dyno is
between 150 g to 380 g, depending on the type of hub used before and on the hub dyno.....For the weight weenies there is still the velogical generator at 75 g additional weight. No solar panel/battery combo can top this
