thebulls

The light pattern from virtually all dyno lights is useful and does not piss drivers (and fellow randonneurs) off by blinding them. The light pattern from virtually all battery lights is symmetrical and pisses drivers and fellow randonneurs off when it blinds them. And if you tilt it down enough that it doesn't blind people, then you have an intense white spot that is too close to you and blinds you from being able to see long distance. An exception is the B&M Ixon IQ, but that is pretty heavy with 4 AA batteries and barely makes it through the night.

And I suggest you go re-read Peter's site. He's not great about updating reviews so there's a lot of stuff about how wonderful the beam pattern is on an E6. Other reviews of old technology LED's have also not been updated. But the photos of beam patterns tell the whole story ... look for the B&M Cyo Premium, B&M Luxos, and Edeluxe II, all of which use B&M's latest lens and LED technology. I have a Luxos-U and the beam pattern is so far superior that I doubt I'll use my old Cyo's except for commuting. The Luxos puts a beam all the way across the road so you can see well when you're going around corners on a mountain descent at 40mph.

Dyno power losses when the lights are switched off are negligible. Power losses when the lights are switched on are minimal. Over the last 8 years of riding with dyno hubs, I have ridden hundreds of miles in the daytime with my lights switched on because I forgot to switch them off and didn't notice they are on. With a Schmidt hub, and a modern LED light, the power loss is more like 4 or 5 watts than the 7 that you are using. For a randonneur, the premium is on being able to have reliable light that lights up the road usefully and properly at high speeds, night after night. If that costs a little bit of power at night, so be it. That said, like Homeyba when I'm on a steep climb and at the end of my rope, I'll sometimes turn my dynamo light off, mainly because of the psychology of having something that creates any additional drag (while not being necessary at 3mph).

My suggestion: If you are still puzzled about all of this, train yourself up for and then ride a 1200km. In the process, you'll be doing enough serious night-time riding with riders using all sorts of different lighting systems that direct observation will eliminate any puzzlement. And you'll have a lot of fun doing it.

Nick Bull

PS, The beam pattern on an E6 was really good, and with a dual E6 system you get pretty good light across the road. But it's still a bit like running a marathon at night while holding a candle lantern.