On Fri, 1 Apr 2016 10:20:16 -0000 (UTC), Yin goo
wrote:
I have a couple old but functional dynamo - One bottle, one roller.
I'm wondering if the electrical efficiency/efficacy can be improved by
rebuilding the dynamos. Has anyone have any experience with this? I
understand that i could potentially rewind the coils, replace the
bearing but how practical is this ... Before i attempt it on an
otherwise functional device. What else is practical to change; the
magnet? More poles? Any other interesting hacks or improvements?

I suspect not other than making sure the bearings are lubricated. Well,
I guess that would depend on how much you understand electrical
engineering and what tools you have.

I have a Sanyo roller and Andrew sent me instructions on how to tear
down and rebuild it. Probably has to be done ever 10 years or so.

The modern hub dynamos are very very good- Schmidt, Shimano, Shutter,
etc. The new generation of LED head- and taillights are likewise very
good. While I found my halogen headlights perfectly fine for all-night
rides in the country, the LEDs are usefully brighter and the optics are
improved to focus the light on the road and not in driver's eyes. If
you really want to improve the utility of your existing dynamos, just
upgrade the lights. My Schmidt eDelux is excellent and there are some
more refined lights that have come out since.