This article is from the Misc Bicycles FAQs, by various authors.
From: email@example.com (H.Verhaar.)
Here in Holland, with over ten (I think it was) million bikes for 14
million people we use generators all the time; practically no
battery-powered lights available. I can highly recommend the Sanyo
generators, they produce a behind- the-bracket mounted type that rolls
on the tread of the wheel, and a rim type. The rim-type generator is
especially good and it comes with its own, tiny but adequate,
headlight. If you have the special fenders with electricity wire
molded into them (made a.o. by ESGE) installation of a total lighting
system is dead easy, otherwise you'll have to mess with wires. I don't
know if Sanyo generators are available in the US, but if not, maybe we
can work something out.
From: firstname.lastname@example.org (Robert M. Grove)
I use a Royce/Union generator which is about 10 years old. I know its
been used at the very least 500 miles at night. It is a "block-type"
generator where the headlight and the generator are a single unit
which mounts in front. I drive a small taillight with it (.5W) and I
have a quick connect on the tail light wire so that I can hook up the
trailer light when towing the Equinox at night. Other than a few
bulbs, it has worked and held up well.
The light is not easy to adjust since the headlight is part of the
generator, and it doesn't work when stopped. It is also inadequate for
moderate speeds unless you are sure there are no rocks, old muffler
pieces, tire treads, etc. in your path.
I used to have 2 generators mounted, one front and one rear. The rear
was a cheap off-brand made-in-Tiawan generator that did not last very
long before the generator bearings went. I have a new Sanyo that I
have never mounted so, I can't tell you how well they hold up, but the
Union has held up very well.
Sanyo generators are available in the US. The under BB mounted ones
even come with an (optional) voltage regulator for those who ride fast
and/or use halogen bulbs (they 'fry' with too much voltage).