Originally Posted by
ItsJustMe
You realize that the lumens rating on those lights is theoretical, right? In reality they probably put out half that. They rate them at the theoretical maximum light output as stated by the manufacturer of the LED emitter, assuming that you get the best of the best, top bin select LEDs from the batch and drive them with a perfect driver circuit with a large, efficient heat sink. This is never the case.
That first one is more like 1500 lumens (mine is the 1200 lumen version). The heatsinking has gotten a lot better. You folks should really check out
http://forums.mtbr.com/lights-night-riding/, way more info on lights.