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/
--
- Frank Krygowski