Trail Tech ( I think ) makes a self-contained HID race light/battery pack combo that clamps on the forks in minutes and will run the light for about 4 hours on a charge. EXPENSIVE, though. Something smaller/lighter/cheaper can be had just as a trail light to deal with getting back late. I have the trail tech set up and at night I can ride as fast at night as I dare ride during the day in open desert. Tighter single track I can ride fast but not full speed. The amount of light put out by the light is truly amazing it's just light does not bend so some times in the single track stuff it's hard to see how deep holes are.