My NiteRider light was off getting fixed at the factory and I needed something for my daily commute. I have used it in a 45 minute pouring rain commute on the way in to work and it worked like a champ.
Step 1: Parts
18 Leds (white 25000mcd)
Reflector w/ bracket
9v snap connector
Old Bay Tin
PNP Transistor (3906)
NPN Transistor (2222)
2 x molex KK connectors
Step 2: Solder the lights in
So I soldered 3 white Leds in series to drop the voltage to each led to 4v and be plenty bright.
Make 6 rows of these.
I started on the right side of the breadboard so I could use the left to mount to the reflector bracket.
Step 4: Done for now
You are done if you just want to make a headlight.
I'd say its brighter than my niterider light a 10w but not as bright as it at 15w.
And I gotta be honest, this is a good point to stop. For $6 you can buy a nice Red LED VistaLite blinky. Might as well use one of those, and use this light for the headlight..