On Fri, 28 Nov 2003 22:38:57 -0600, Tom Sherman <
[email protected]> wrote:
>
>Tim McNamara wrote:
>>
>> Tom Sherman <
[email protected]> writes:
>>
>> > Benjamin Lewis wrote:
>> >>
>> >> Tom Sherman wrote: ...
>> >> > By high speed I was referring to speeds in the 40+ mph (70+ kph) range, which are easily
>> >> > attainable on a moderate hill.
>> >>
>> >> ... and a decent generator such as the SON can easily cope with this speed, from what I've
>> >> heard.
>> >
>> > To clarify: my concern is having enough light to see the road, not burning out the hub from
>> > excessive speed.
>>
>> Well, then, to follow up on my previous post. I have plenty of light descending at 35-40 mph on
>> twisty rural roads with my Schmidt SON and Lumotec Oval headlamp. I've ridden literally dusk to
>> dawn with it on several occasions as well as using it for those rides when daylight just doesn't
>> last long enough to get in a decent ride.
>>
>> At PBP this year, I was amazed at the poor coverage of many battery powered lights, even those
>> with 10-15-30 watts of output. My 3 watts lit the road better than those lights, which tended to
>> have a very bright pool of light right in front of the wheel, so bright that it worsened people's
>> night vision. I had people turn off their lights and follow me at night- partly to conserve
>> batteries but also commenting that they could see better with my system than theirs.
>>
>> A good lighting system is not about turning night to day, as too many people seem not to
>> understand. It's about making the things you need to be able to see clearly visible. If your beam
>> is too intense and lights close objects too brightly, then you'll actually have *more* trouble
>> seeing the road in an effective manner because your eyes do not dark-adapt.
>>
>> The Lumotec Oval and the Bisy lamps for the SON hub provide an effective beam distribution- broad
>> enough to see an entire two lane road from edge to edge, and brighter at the top to make distant
>> objects visible. Most high-power battery systems use a lamp designed for movie and slide
>> projectors, with an even circular field and a rather sharp drop-off outside of the cone of light.
>> Such lamps should be mounted very low- e.g., near the hub- and aimed nearly horizontal to be of
>> best use; unfortunately they are normally mounted on the handlebars.
>
>Well, I got spoiled by driving a car with 4 110-W Hella lamps up front, so I understand the night
>into day concept.
>
>The real reason I want a really bright light has to do with the behavior of motor vehicle
>operators. On issue is that many of them will not dim their high-beams for an oncoming cyclist. A
>quick flash of an 80-W high beam would solve this problem (except for the idiots who never dim
>their lights). The second is that many motor vehicle operators assume that all bikes move at
>10-mph or less, so they deliberately cut off cyclists when turning at or crossing intersections.
>Ir they think it is a motorcycle approaching, they will assume it is moving at a typical motor
>vehicle speed.
>
Let me tell you, i have never been cut off or anything at night with my 55 watt light. It only lasts
a bit over an hour though.
>Tom Sherman - Planet Earth
