Cycling & bikes - Jan Heine on headlights

The current issue of Bicycle Quarterly
http://www.bikequarterly.com/current_issue.html
has a road test of a Calfee carbon fiber randonneuring bike. The road test is very unusual. Rather than the spin-around-the-block and "gee whiz" reports you get from Buycycling magazine, this one is a report on a 383 mile, essentially non-stop ride in the mountains of Washington State, with 37,200 feet of climbing, riding day and night, often on unpaved roads. And the guy is fast. IIRC, he still holds the tandem record for Paris-Brest-Paris.

Jan liked the bike, even though he's been less than impressed by carbon fiber in the past. But let me quote him about the headlight:

"Darkness comes quickly... The Exposure Revo Mk1 light is powered by an SP-Dynamo PD-8 generator hub. The light uses four LEDs to project a beam that is impressively bright and wide. Road signs far in the distance are illuminated. As it gets darker, I become less pleased with the headlight's performance. The simple, round beam pattern puts a lot of light in the near field, so my eyes adjust to the bright light. Yet further ahead, there is too little light, because the beam hits the road at a shallower angle. So while the near field is too bright and road signs are illuminated half a mile away, potholes and curves that are 30 m (100 ft) away look "washed out", as little light reaches the road there. The headlights I usually use feature sophisticated optics that put most of the light near the top of a well-defined beam, so the road further away from the bike is illuminated as brightly as the closer range..."

[Note: I'm pretty sure he normally uses Edelux lights. You know - German standard, and all that.]

"... People are heading out to the many camping spots... The round beam of my headlight is illuminating the tree tops as much as the road surface, and I can see that it also blinds the drivers of oncoming cars...

"... I am thinking of covering part of the lens with dark tape to prevent blinding oncoming traffic. This makes me realize how much of the light output is wasted to illuminate the tree tops rather than the road."

"... The quick releases for both head- and taillights mean that I have to take both with me whenever I park the bike, lest they be stolen."

It's almost like he's been reading these discussions.

Please note, his riding with either this or with his usual Edelux is _not_ just in well-lit cities or on cycletracks!

- Frank Krygowski