Originally Posted by
Homeyba
I seriously doubt that it is that much. I rode my fastest 600k (just under 23hrs) using a generator hub. I don't think I could have gone anywhere near hour faster without it. You have to also take into account the fact that you are only pulling that higher wattage when the lights are on which is generally only at night. Plus you ride faster with better illumination of the road, especially on descents. So, it's not a simple wattage question.
To do a 600K in under 23 hours, your power/speed relationship was well outside the linear range. You probably ride the flats at 35kph+ where aerodynamics trump frictional losses rather quickly. The dynohub impact was probably more like 20 minutes on your time. For a slower rider using all of the allowed time, the impact would be over one hour.