Commuting - Yet another question on dynamo-based lights

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Juha
09-07-04, 02:31 AM
For those of you who use dynohubs or bottle dynamos with 3w headlights: have you had problems with bulb life? Are the zener protection systems in lights good enough to actually protect the bulb?

I just read a post from a fellow commuter in another web site, and he said he got so fed up with fried bulbs that he finally installed a 8V bulb for the 6V system. That bulb has apparently lasted for several years now. Previously he had also tried adding a suitable resistor to the circuit, but that design got stolen before he had really chance to see how long it would last. Because of this experiment I think it is safe to assume he was not going through 2,4w bulbs in a 3w system.

So, what kind of bulb life do you consider acceptable?

--J

PaulH
09-07-04, 07:32 AM
I use a Shimano hub dynamo and a Lumotec headlight. Bulbs normally last a year or more.

I have had problems with the 6V .6W tail light bulbs, however -- they burn out frequently (monthly, I recall) and it is difficult to find exact replacements here in the US. I switched to a B&M Standlight (an LED tail light), two years ago, and it has been great.

Paul
randya
09-07-04, 12:39 PM
Reflectalite has inexpensive dynamo regulators to prevent this from happening in unprotected systems (like the older Union dynos); I've never had a problem with any of my newer B&M systems, they all still have the original bulbs.

http://www.reflectalite.com/regulater.html

Rowan
09-07-04, 05:46 PM
It is important to NOT touch the glass surface of the halogen bulb for the Lumotechs (or any other system, I suppose), as the oils transferred from the fingers to the bulb will etch in and shorten the life of the bulb.

A friend and I who converted to dynamo systems about two years ago (we both now run SONs with Lumotech Ovalpluses) have found our bulb life has extended greatly by rinsing the bulbs in alcohol (methylated spirits for us, rubbing alcohol for North America) prior to fitting. This removes any oils and other dust, grime, etc.

I ride a lot at night, and have been using the same bulb since before the beginning of the year.
randya
09-07-04, 06:05 PM
Reflectalite *claims* that their bulbs are unaffected by dirt and oil. From their website:

"Our Halogen bulbs are not damaged by being touched as they are made from hard glass, not quartz."

http://www.reflectalite.com/halogenpage.html