I can't imagine riding at night without a handlebar light and helmet light. The handlebar light is big and throws the light I need for safety. The helmet lets me look at my computer, whose internal light is insufficient for my old eyes and it lets me work on something when I'm off the bike. Last night I needed my helmet light as I took off one layer and stuffed it in my rear bag and worked the snaps and such. My helmet light is a Petzl RXP (if I have the letters right) and I attach it with zip ties. Very effective.