A 15 degree spot is OK as a helmet light, but not exactly ideal on the bars. At 100 feet, a 15 degree spot is 26 feet wide. At 10 feet its very bright, but only 2.6 feet wide. Not exactly what I'd like to drive behind. Wide beams for close coverage coupled with a spot on the helmet is a better set-up to drive with.
A couple lights will easily put you past the 1,000 lumen mark, but a single 1,000 lumen spot is the least practical format I can imagine.
Last edited by Burton; 10-12-12 at 10:59 PM.