As an aside, many of the LED bike headlamps I have seen (just like LED car headlamps and most LED hiking/camping lights) are unpleasant and a safety hazard. They are very bright in the blue part of the spectrum, which means they cause severely distracting/blinding glare for anyone else on the road, and knock out people's night vision. Personally I think they should be heavily regulated and forced to be less bright and maybe larger or more diffuse, with a more night-appropriate spectral power distribution.