My previous bike light used a Luxeon III LED,
http://www.ghostgum.com.au/misc/BikeLightV1.htm
and was based on Suzy's design
http://www.littlefishbicycles.com/bikelight/index.html

Since then, Cree released the XR-E LED with twice the efficiency of the older Luxeon LED. It was
time for a simple upgrade by replacing the LED and optics.

The results can be seen at
http://www.ghostgum.com.au/misc/BikeLightV1_5.htm

Old light was 80 lumens, new light is 170 lumens. The new beam has a bright spot in the middle, 4
times as bright as the old beam. I confirmed the improvement - I can see the spot on the road under
street lights.

Another method suggested for a bike light is to strap one of the Fenix torches (L1D CE or L2D CE) to
the handlebar or helmet.
http://www.torchworld.com.au/catalog...ducts _id=371
http://www.torchworld.com.au/catalog...ducts _id=370
These give 90 - 135 lumens on turbo power setting using one or two NiMH AA cells.