I bought a 1973 Schwinn Continental a few days ago and since it came with a dynamo-powered head lamp and tail light, I decided to retrofit them with LEDs and hook them up to a battery pack.

The most elegant solution for the lights is to use LEDs that have an E10 (miniature screw) base like the TLE-1S, which is a replacement for a flashlight.

http://www.batteryjunction.com/tle-1s.html

Now the questions: Is 50 lumens going to be enough for me? Are there other places to look for similar (stronger) LEDs that have a base like that? Should I just abandon this approach altogether and use a different type of LED?