put our Heads Together
Join Date: Jun 2003
Location: southeast pennsylvania
Bikes: a mountain bike with a cargo box on the back and aero bars on the front. an old well-worn dahon folding bike
i'd recommend against the ones you can buy at canadian tire/kmart/similar stores. The one I got was usable, but not really worth the $10 USD i paid for it. It had an overheating problem. (would shut off until cooled off, if i rode faster than ~ 12mph for more than a couple minutes) The incandescent bulbs burned out fairly quickly too.
I switched to cateye LED lights that I use on blinking mode, and I rarely have to worry about batteries-- i recharge 'em every 4 months or so.
You may have already known this, but from what I hear any sidewall generator is a poor choice in the rain. The one I had was hopeless in the rain, in any case.