By now I've tested my Supernova E-3 tripple and shimano dynamo hub combo on a few trail rides and I can say that this thing is great! More than enough light power for single track. In combination with a helmet mounted light its all anyone would need IMO. It's not cheap, about 450$ but you don't need to mess with batteries, for me its worth it. There's no noticeable drag from the dyno hub. At slow speeds, like going uphill or going around a tight switchback you loose a little bit of light, cause it drops down to one led but its still enough to see well. At low speeds it still out shines my Tikka XP.
Happy trails!
Phil
Now that is a good looking light! 550 lumens from a dynamo - that's a lot of light. Plus, a dynamo is a lot cheaper than all the rechargable batteries I've invested in...
It drops down to one LED at/below 8mph. While I like the concept of more light at speed, I'm not so sure the light would offer sufficient light at low speeds in the techy stuff. Any comments on that aspect?