Here's a little something for those 4-5 hour epic backcountry rides with 40mph downhill sections. My goal with this light was to develop a light that's very efficient with long runtime at ~700 lumen and also provide 1500+ lumen when needed.
This light has 10 Q5 WG emitters and I included 3 red emitters to improve color rendering. Next time I think I'll use 3 amber emmiters instead, this one is a little too rosy for my taste. Driving everything at 600mA it should be putting out ~1800 lumen and consuming around 25W. The housing is 2.5" OD and 2" long and weighs about 250g complete. I made the wall thickness pretty thick on the housing and the optics are behind 1/4" Lexan, so this light should be indestructable!
Beamshots will be coming soon. The light is with a friend of mine at the Icycle race (link: http://jandwevents.com/info.html ) in Fontana, NC right now for some night DH racing action. When he comes back I'll do some shots comparing the effects of the red emmiters with amber ones.