Tourist in MSN

The vibration is from the magnets as the wheel rotates, that is not drag. When you turn the wheel slowly by hand, you can feel a notchyness (if that is a word) to the way it turns, but that is normal for these hubs.

I use the SP PV-8, not the SON but the two are quite similar for statistics. I feel no vibration, but it is on my expedition bike which is a very robust frame. If you are feeling vibration, it likely is an resonance in a light weight frame which would only be an irritation, not drag.

My SP has no perceptible drag when I ride it. During the day I often leave my light on because it really does not seem to slow me down at all.

With the light off, if I lift the front wheel off the ground and give it a spin by hand, I can see that the wheel slows down quicker with the light turned on from the additional drag, but with the light off the wheel will spin almost as long as a non-dyno hub wheel would spin.

This link is to an article that has several laboratory measured factors including drag. (Th article is not loading right on my computer today, but probably will later.) One of the graphs lists drag with the light on and off for several different hubs at different speeds.
https://www.cyclinguk.org/file/public...ub-dynamos.pdf

dwmckee

I use the DC version (battery powered) of the Edelux II which is not well known, but it is excellent. I use rechargable battery packs that have 4 18650 cells in them and get at least 5-6 hours on a charged pack. The packs are smaller than my wife's fist (maybe a bit less volume than half of an average apple?). I have two dyno systems as well, but I am probably the exception that has switched to battery lights for distance riding (still use dyno for other riding). In distance rides, the slight but eternal drag of the generator has always nagged at me. Does not bother me for other riding though.