Originally Posted by
tjspiel
Thanks for the information. Specifically I want something bright enough to be able to judge the contours of ice and snow covered streets. In the summer I can get by with less light.
Are you recommending using a battery powered lamp in addition to the dyno powered one? If so in my mind that kind of defeats the purpose.
In today's world of good LED lights with long run-time and even better rechargeable batteries, LED battery lights really trump dyno lights. I do like dyno lights because they are always there - ready to go whether you forgot and left your light on and burned out the batteries, or you are hopping on the bike after letting it sit for months or years. The dyno is always ready. There are shortcomings of dyno lights of course, such as difficult maintenance, unit expense, no lights when stopped, etc.
However, if you are a regular commuter, you will be dialed in to your lights/battery needs, maintenance, and replacement timing.
If you do use a dyno, it is STILL a good idea to have some kind of battery light in addition so that you have some light when you stop. With an additional battery light, you can also have two focus zones on the road.