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Old September 12th 17, 08:39 PM posted to rec.bicycles.tech
Frank Krygowski[_2_]
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Posts: 7,511
Default Is there an updated Dynotest somewhere?

On Tuesday, September 12, 2017 at 6:50:39 AM UTC-4, sms wrote:
On 9/11/2017 11:59 PM, Sepp Ruf wrote:

snip

For Rob who might experience mental drag uphill from just having to see a
big, heavy, non-laminated hub slowly revolving in the front wheel, the
smallish Shimano DH-T780-1N, 1.5W 250mA class, might suffice[1] once he
grows sick of the Soubitez. Best price I see is 96 euros a pair from CNC
Hamburg on ebay, no overseas shipping available, though.
http://www.ebay.com/itm/253093811841

[1]
DRL does not require more than 100 lumens if you get the optics right.


True, but if you want a dynamo light for more than just a DRL then that
won't do.

I have an SP dynamo (relabeled as "Joule") on a 20" wheel on a Dahon.
It's coupled to a European dynamo light with about the best optics
available, but at a claimed 200 lumens it's still really only useful as
a DRL, plus it does not have a flash function.


... Even at perfect efficiency you;re not going to be able to run even a
mid-range 1000 lumen light, let alone the 2500+ lumen lights that bicycle
commuters require.


Good grief. The "Danger! Danger!" crew is insanely into the lumen wars. After
many decades of millions of commuters doing perfectly well with 80 lumen
halogen bulbs, how is it suddenly "required" to have 2500 lumens?

BTW, I saw a new phenomenon yesterday. Driving along a two lane highway, I
saw a very bright flashing white light from about a mile back. I wondered
what sort of emergency vehicle or road work it might be.

Over a minute later, I passed a bike rider. She had an insanely bright bike
headlight mounted on the back of her bike, pointed back at traffic. As I
changed lanes to pass (which I would have done anyway) the thing was so
bright that it literally hurt my eyes.

It's illegal for a white light to be pointed rearward like that. But I'm sure
the rider felt that it was so dangerous to ride a bike that she should
violate that law, and also blind or inconvenience any other road users.

- Frank Krygowski

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