Dynamos - obsolete?

The Rev Gaston wrote:
I have just bought a "commuting bike" - tradiional Dutch town bike,
complete with hub brakes, sturdy pannier rack, bell, etc etc.

It also has a dynamo front light, which, when I bought it, seemed
like a plus. But now I'm not so sure, and I wonder if the new bright
LED's with long run-times per battery have rendered the dynamo light
obsolete.

My dynamo light is:
heavier than an LED
gives a less bright light
is more expensive
is more difficult to pedal

So why do people swear by them? Of course they avoid using batteries,
so are more eco-friendly, and they're more difficult to steal, but
apart from that?

For my part, I use a bottle dynamo on my station bike because
- its bright enough for use on unlit lanes (B&M 2.4w front lamp).
- its always there, just turn it on
- the "stand light" facility gives enough protection light when
slow/stationary.
- no batteries to remember to charge
- no batteries to purchase and replace (even rechargeables die eventually).


But to analyse it more carefully, cut the problem into two parts - power
source and bulb technology.


For power you have Battery vs. Dynamo.

Good hub dynamos have negligible drag when off, and not much when on.
They don't need careful battery management (many rechargeables need that).
They produce enough power for road use.


For light you have bulb vs LED.

Either can be driven by either power source.
LED is improving very rapidly, to the extent that possibly the best dynamo
lamp may be the Solidlights LED twin unit (at a mere £130), and there are
various LED dynamo lamps at lower prices.




- Nigel


--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/