On 2/8/2018 6:52 PM, Frank Krygowski wrote:
On 2/8/2018 3:08 PM, Joerg wrote:
On 2018-02-07 07:01, AMuzi wrote:
On 2/7/2018 12:06 AM, Tosspot wrote:
On 07/02/18 03:56, Frank Krygowski wrote:
On 2/6/2018 1:52 PM, sms wrote:
My wife's Lezyne Deca 1500XXL stopped taking a charge, at
all. Taking it apart, I saw that the batteries were made
in July 2015. Not too good for it to stop working that
soon.

Some of my bikes have dynamos that are 30 years old. They
just keep going and going and going...

I bet the lights don't, as he peers at a collection of
CYOs[1] and a recently defunct Flat-S. Tbf the Flat S is
around 7 years old.

[1] Not one lasted 18 months, they simply aren't waterproof
imho.

My regular glass bulb lamps go 6~8 years between bulb
failure in daily
use. YMMV


Ye olde 2.4W + 0.6W with a dynamo? When riding at a good
clip, meaning north of 15mph, those never lasted much
longer than a month for me. Even if they didn't blow their
filament right away the bulbs turned black inside and
became dimmer than they were already to begin with. When I
was a teenager I started equipping my bikes with what the
automotive industry already understood over 100 years ago,
brighter lights, a battery and charging system. Soon the
German police wanted to give me a ticket for
"non-standard" lighting. Luckily by that time I was a
Dutch resident and they had to let me go.

Those 2.4W bulbs were a joke.

I think you missed about three generations of dynamo
lighting technology.

My first dyno had a vacuum bulb. It was terrible at lighting
the road, but fine as a "be seen" light, better than the
battery lights available at the time. Yes, the bulb
blackened a bit after a while. That meant the bulb needed to
be changed. And yes, it wasn't wonderful overall; but at
that time (early 1970s) I knew of no really good bike light.

My next dyno set came with a krypton bulb. It was
significantly brighter. The optics of the headlamp were also
a tiny bit better. This was better at lighting the road, but
still not great. It was more than fine for a "be seen"
light. (Contrary to modern myth, it takes very little light
to be easily seen and noticed by other road users.)

Incidentally, I don't think I ever burned out a bulb with
either of those lights. But I didn't ride fast with either.

When I eventually told my bike shop friend I wanted to see
better, he sold me a Union lamp with a halogen bulb. This
was my first headlamp that actually focused the light
properly on the road. (It was StVZO compliant.) With that, I
was finally able to see the road well enough for all the
riding I did. And this headlamp had two zener diodes in the
circuit, which pretty much cure the bulb-blowing problem.
(Interestingly, after years of use, one of the zeners
failed. But by then I had other headlamps to choose from as
replacements.)

For a long time that was my setup but I was interested
enough to do various experiments. I played with various
battery lights, both commercial and homebrew, including a
couple with external battery packs. I decided they offered
minimal practical improvement over the dyno lights and were
not worth the inconvenience. I learned that optics were key,
and I learned that some headlamps had better optics than
others. I compared dyno headlamps by mounting two of them,
with a switch that allowed either one or both to be active.
And BTW, those were mostly 2.4 Watt bulbs, although I tried
a 3 Watt for a while. I also learned that some dynos
produced a bit more power than others.

The experimenting ended when I bought my first Cyo. It
became obvious to me that this produced more light than I
needed, so I considered the problem solved. Later versions
were even better. By now, I've had friends with other
battery lights praise my headlight, saying (for example) "I
want to ride next to Frank. His headlight is great!"

The overall point is this: The vacuum bulb headlamp someone
used in Germany in the 1970s has as much relation to current
dyno light technology as a MIFA has to a Trek Madone.

http://www.telegraph.co.uk/men/think...-on-a-50-bike/





Thanks for that, a good read and inspiring too.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971