500 Lumen, 3C, Adjustable Beam, 3 Mode Cree LED Flashlight 2 for$24.99 at Costco

On 2/27/2013 7:13 AM, Jay Beattie wrote:

That would not be practical for me since I would be switching between
disc and caliper brake bikes -- and riding my commute wheel on a
racing bike wouldn't be much fun anyway.

The bottom line is that you really need a dynamo hub wheel for each
bicycle, but moving the headlight from bike to bike could be made easy
with appropriate connectors and clamps. It's not just different types of
700C wheels for commute bikes and racing bikes, it's 26" or 29er wheels
or even 20" or 16" wheels (for folders).

But once you have a dynamo wheel for each bike, if you're reasonably
mechanically inclined you can have a very good LED dynamo light for each
bicycle at a cost of about $12 per light (no strobe function though).

That doesn't address the issue of the relative low light output of
dynamo lights versus battery powered lights of course.

I like being able to grab a light, snap it onto a holder on the
handlebars, and go, not starting to unbolt and bolt things and move
wheels around. Sure you can get could at the swapping and get it down to
5 minutes or so, but grabbing a battery powered light and putting it on
the bike takes only seconds.

On Feb 27, 4:33*pm, James wrote:
On 27/02/13 15:47, Frank Krygowski wrote:









On Feb 26, 3:57 pm, *wrote:

It takes me all of a couple (2) minutes to undo one bolt, remove my
dynamo, the wire and light from my bicycle. *It would take a few (3)
minutes more to put it on to another bicycle.

If you had a dynamo front hub I suspect it would be a similar time, or
possibly less. *It would depend on the type of light mount I guess.

I haven't bothered to make my current headlights or dynamos easily
removable or switchable from bike to bike, but it can certainly be
done. *I've done similar things with older headlights, fenders, bike
bags, etc. *It generally requires some mechanical cleverness, plus
investing the time to fabricate mounts or do other minor
customization. *You have to want to do it badly enough that you'll
invest the time, hoping to eventually save time during repeated
installations& *removals.

Time saving was not really the issue. *Jay said:

I also like lights that can be switched from bike to bike -- and
mostly retired after daylight savings time, which kind of disqualifies
dynamo lights, although I could keep a dynamo on a dedicated commuter.

I was giving him an idea that using a dynamo and light does not mean a
dedicated bike for night riding, that you _can_ swap from bike to bike
if you want, and it's not all that difficult.

I understand. My point was: for those interested, spending time to
make the change easier can save time down the road. It's much like
(say) spending money on insulation to save heating bills.

I tend to fix little things that irritate me on my bike, even if it
requires some customization. For example, back when I used to remove
fenders for club rides and time trials, I spent some time making sure
they could be taken off or installed in just a couple minutes. Other
folks might not mind spending fifteen minutes or more on that task.





For me, I leave the dynamo and light on my bike 99% of the time. *I
remove before a race, and reinstall after. *It costs me 5-6 minutes.

But by removing generators and lamps, you run the risk of being out
later than you thought, and realizing that you didn't reinstall it
this day, or on this bike. *I greatly prefer having a light on each
bike. *(Well, except one, right now.) The bikes are ready to go, day
or night.

You see, that doesn't affect me. *How does it go? *Oh yes, I remember,
something like, "Yet another negligible problem in bicycling." *;-)

I like that. Can I use it?

- Frank Krygowski

On Feb 27, 10:13*am, Jay Beattie wrote:
On Feb 26, 8:47*pm, Frank Krygowski wrote:









On Feb 26, 3:57*pm, James wrote:

It takes me all of a couple (2) minutes to undo one bolt, remove my
dynamo, the wire and light from my bicycle. *It would take a few (3)
minutes more to put it on to another bicycle.

If you had a dynamo front hub I suspect it would be a similar time, or
possibly less. *It would depend on the type of light mount I guess.

I haven't bothered to make my current headlights or dynamos easily
removable or switchable from bike to bike, but it can certainly be
done. *I've done similar things with older headlights, fenders, bike
bags, etc. *It generally requires some mechanical cleverness, plus
investing the time to fabricate mounts or do other minor
customization. *You have to want to do it badly enough that you'll
invest the time, hoping to eventually save time during repeated
installations & removals.

That would not be practical for me since I would be switching between
disc and caliper brake bikes -- and riding my commute wheel on a
racing bike wouldn't be much fun anyway.

Well, once again, hub generators are not the only game in town,
despite the claims of some. Most of my bikes use other generator
types, either bottle or roller. If they didn't work well, I wouldn't
use them.


As for providing enough light, I "need" as much light as I can get. My
night vision isn't what it used to be, and my current 750 lumen
Niterider is just O.K. -- and it is a well made light, although some
could argue that it has unnecessary upward light spew, but that
actually comes in handy in some places.

I'll repeat my recommendation that you check out a modern, road-
designed LED headlamp. There must be _someone_ in Portland using one!

As I've described befo Back in the lead-acid halogen days, my best
cycling friend got a good buy on what was supposed to be a fairly high
power (10 Watt? 15 Watt? I forget) rechargeable battery light. We
compared it, side by side, with my 2.4 Watt generator-powered light.
No contest - my light gave much better _usable_ light. His gave a
useless fog. I saw the same thing with another club mate's dual
rechargeable setup. And the Scharfian idea that a focused light is
invisible to others is just false, as shown by every car headlamp.

I know you can get a bright LED/dyno set-up if you pay enough, which I
might be willing to do at some point, but I typically lose interest
after daylight savings comes. *Unless something earth shattering hits
the market, I'll probably just stick with my battery set up -- which
sits on the back counter for a significant portion of the year.

I understand. I'm quite happily typing this on a minimal Linux
netbook, rather than a fancy tablet. Sometimes good enough is just
fine.

And yes, some tasks really are better served with battery lights.
Your off-road excursions may qualify, if they're beyond "stand light"
range.

But I do hate myths being used by some to claim generators are always
super-expensive and inadequate. There are millions of counterexamples
proving otherwise.

- Frank Krygowski

On Feb 27, 12:03*pm, SMS wrote:

A lot depends on your velocity. For the types of commutes in my area,
and my night vision, 750 lumens is certainly adequate. The spousal unit
complained when I put a slightly smaller light on her bike that was only
500 lumens...

I bet she too has never tried a modern, German-standard LED headlamp.
Right?


The light mentioned in the subject above might work for her because the
beam is adjustable. I tried it last night (walking) and it seemed about
as good as her present light.

Based on your posts here, the amount you've spent on Chinese-made
discount flashlights could have bought B&M LED lights for your entire
family!



The Super-Nova E3 Triple looks like it might do the job for a dynamo
light at 800 lumens, but it's $300, just for the light. By the time you
get a new wheel with a hub dynamo, you're at a price that not many
people will pay for lighting. Also, Peter White warns against turning on
this headlight if you're in motion, as there can be a surge that
destroys the light. Wonderful, a $300 light with no protection against
something that a rider is often likely to do! However the E3 triple
finally brings a sensible beam to dynamo lights.

I expect that the 800 lumens is only achieved at quite a high speed,
since the generally accepted maximum lumens per watt is 100, and a 6V
dynamo is rated at 3 watts.

Dynamo Watt ratings are not maximums. They are based on use of a 12
Ohm resistive load, equivalent to a 3 Watt halogen bulb. If the
dynamo sees a 24 Ohm resistive load, it will produce 6 Watts. It's a
common trick. In practice, almost all bike dynamos operate as
(approximately) constant current devices, putting out between 0.5 and
0.6 Amps, except at very low speeds.


Not sure where to find actual power ratings of dynamos. There's an
amusing article at http://www.bikequarterly.com/VBQgenerator.pdf where
they have a graph of power measured in volts, LOL. Clearly the authors
have no engineering background.

:-) Yes, that was a mistake, one which (IIRC) they apologized for in
a subsequent issue.

OTOH, a certain web-based "world's greatest expert on bicycle lights"
still has a table showing that increasing reflector size increases the
lumen output of a bulb. LOL indeed!

(For the non-engineers: "lumens" measures total light output in all
directions. Larger reflectors don't change a bulb's lumen output;
they just direct more of the lumens forward.)



There's a test at
http://www.myra-simon.com/bike/dynotest.html where the author
understands that power is measured in watts, and the highest power they
get is about 4.7W at 40km/h, but he hasn't tested any of the newer,
higher-efficiency, hub dynamos. I seem to remember seeing something that
6W was possible on some 6V dynamos at high speed.

When I was using halogen headlights, I was getting 12 volts, 6 Watts
out of an ancient Soubitez roller dynamo (_not_ a hub dynamo) at about
13 mph. It doesn't require a hub unit, and it doesn't require high
speed.

There are also 12V/6W
tire driven dynamos available, but AFAIK, no company has made a 12V/6W
hub dynamo.

Wrong. Almost all of them will do that. The only reason a bottle
dynamo won't do it is that it's small roller diameter requires too
much torque at that power output, and thus tends to slip.

- Frank Krygowski

On 2/27/2013 1:33 PM, James wrote:

snip

I was giving him an idea that using a dynamo and light does not mean a
dedicated bike for night riding, that you _can_ swap from bike to bike
if you want, and it's not all that difficult.

Most cyclists with multiple bikes have different types of wheels and
tires on each bike so it's much more involved than just swapping wheels.
At a minimum it would likely be swapping wheels and changing the front
tire, assuming the same diameter wheel, and assuming the width of the
rim could accommodate the larger or smaller width tire.

Swapping the headlight could be done rather quickly with the right
set-up (perhaps thumb screws and/or wing nuts), but the real expense is
in the hub dynamo wheel. For a dynamo headlight, things have gotten much
better with the advent of 12V, 4-5W, MR16 LED lamps that work directly
from a dynamo with no additional circuitry needed, and have a near ideal
beam pattern (it's rather amusing that the $300 Super-Nova E3 is getting
rave reviews because of the new beam that isn't just illuminating the
patch of road directly ahead, but is also illuminating off to the sides,
something that many of us have been patiently trying to explain the
benefits of for many years).

At least, due to the increasing efficiency of LEDs, decent dynamo
powered headlights like the E3 are now available at all. For years
(decades actually) dynamo headlights were essentially a joke with very
narrow focused beams a necessity because of the need to focus the very
limited light output directly ahead of the bicycle. Maybe okay for the
Netherlands or Germany, but not a good choice for riding on unlit roads.

I'm glad that dynamo light makers did not just decide to meet the
minimum legal standards. Jeff is right about the danger of setting
standards, but the problem with the German standard is that it wasn't
set based on what is actually sufficient for night riding, it was set
based on what was a reasonable amount of power that could be generated
from a dynamo. If they had set the standard based on a reasonable amount
of illumination the bicycle manufacturers would have went non-linear and
complained that it was too expensive or impossible. You see this sort of
complaining by automakers every time a new safety feature or fuel
economy standard is mandated by the government.

SMS wrote:
On 2/27/2013 1:33 PM, James wrote:

snip

I was giving him an idea that using a dynamo and light does not mean a
dedicated bike for night riding, that you _can_ swap from bike to bike
if you want, and it's not all that difficult.

Most cyclists with multiple bikes have different types of wheels and
tires on each bike so it's much more involved than just swapping wheels.
At a minimum it would likely be swapping wheels and changing the front
tire, assuming the same diameter wheel, and assuming the width of the rim
could accommodate the larger or smaller width tire.

??? I have 10 bikes. 3 of them are equipped with a dynahub light system.
When it is dark or getting dark I take one of those three bikes. Why do I
want to ride my crossbike in the dark or my roadbikes? Let alone with other
tires every other day?
Well, everyone has an excuse not to use dynohub lightning.

--
Lou

On 2/28/2013 10:17 AM, Lou Holtman wrote:
SMS wrote:
On 2/27/2013 1:33 PM, James wrote:

snip

I was giving him an idea that using a dynamo and light does not mean a
dedicated bike for night riding, that you _can_ swap from bike to bike
if you want, and it's not all that difficult.

Most cyclists with multiple bikes have different types of wheels and
tires on each bike so it's much more involved than just swapping wheels.
At a minimum it would likely be swapping wheels and changing the front
tire, assuming the same diameter wheel, and assuming the width of the rim
could accommodate the larger or smaller width tire.

??? I have 10 bikes. 3 of them are equipped with a dynahub light system.
When it is dark or getting dark I take one of those three bikes. Why do I
want to ride my crossbike in the dark or my roadbikes? Let alone with other
tires every other day?
Well, everyone has an excuse not to use dynohub lightning.

Not me. We have five bikes in the fleet with dynamo lighting, with very
good LED headlights. But that doesn't blind me to the reality that in
some situations the dynamo lighting isn't sufficient.

On Feb 27, 5:44*pm, Frank Krygowski wrote:
On Feb 27, 4:33*pm, James wrote:









On 27/02/13 15:47, Frank Krygowski wrote:

On Feb 26, 3:57 pm, *wrote:

It takes me all of a couple (2) minutes to undo one bolt, remove my
dynamo, the wire and light from my bicycle. *It would take a few (3)
minutes more to put it on to another bicycle.

If you had a dynamo front hub I suspect it would be a similar time, or
possibly less. *It would depend on the type of light mount I guess..

I haven't bothered to make my current headlights or dynamos easily
removable or switchable from bike to bike, but it can certainly be
done. *I've done similar things with older headlights, fenders, bike
bags, etc. *It generally requires some mechanical cleverness, plus
investing the time to fabricate mounts or do other minor
customization. *You have to want to do it badly enough that you'll
invest the time, hoping to eventually save time during repeated
installations& *removals.

Time saving was not really the issue. *Jay said:

I also like lights that can be switched from bike to bike -- and
mostly retired after daylight savings time, which kind of disqualifies
dynamo lights, although I could keep a dynamo on a dedicated commuter.

On 2013-02-28 18:34:41 +0000, SMS said:

On 2/28/2013 10:17 AM, Lou Holtman wrote:
SMS wrote:
On 2/27/2013 1:33 PM, James wrote:

snip

I was giving him an idea that using a dynamo and light does not mean a
dedicated bike for night riding, that you _can_ swap from bike to bike
if you want, and it's not all that difficult.

Most cyclists with multiple bikes have different types of wheels and
tires on each bike so it's much more involved than just swapping wheels.
At a minimum it would likely be swapping wheels and changing the front
tire, assuming the same diameter wheel, and assuming the width of the rim
could accommodate the larger or smaller width tire.

??? I have 10 bikes. 3 of them are equipped with a dynahub light system.
When it is dark or getting dark I take one of those three bikes. Why do I
want to ride my crossbike in the dark or my roadbikes? Let alone with other
tires every other day?
Well, everyone has an excuse not to use dynohub lightning.

Not me. We have five bikes in the fleet with dynamo lighting, with very
good LED headlights. But that doesn't blind me to the reality that in
some situations the dynamo lighting isn't sufficient.

I know of no battery powered lights that give me the same amount of
light than 2 of my dynohub frontlights for 3 hours without changing or
recharging the batteries. So the only option for rides longer than 2
hours for me are my two dynohub frontlights.
--

Lou

On 2/28/2013 11:27 AM, Lou Holtman wrote:

I know of no battery powered lights that give me the same amount of
light than 2 of my dynohub frontlights for 3 hours without changing or
recharging the batteries. So the only option for rides longer than 2
hours for me are my two dynohub frontlights.

Just because you don't know of any doesn't mean that there aren't any.
It's the only option for you solely because of your lack of knowledge,
not because there are no other options.