Light works

Ian Field wrote:


"Phil W Lee" wrote in message
...
Joerg considered Thu, 28 Aug 2014
12:33:45 -0700 the perfect time to write:

wrote:
not so.....night riders in the park are seen with midlevel systems
both on bike and helmet....good enough for 25 mph on pavement.


25mph on pavement ... yawn

What I meant is something that also holds up at 25mph on a bone-rattling
trail. Like it does on cars. No super-expensive boutiques stuff, regular
affordable gear, just like on cars or motorcycles.

Thing is, the energy budget is far higher on those, as they literally
throw the stuff away (via cooling systems).
On a bicycle, you either have to carry the energy with you in the form
of batteries, or generate it using your own muscle power, so the
energy available is much lower.

There's not much point in carrying batteries big enough for car
lighting on a bicycle in order to be safe at 25mph, if the weight of
the batteries slows you down to 15mph.

Lithium batteries are about as light as batteries get.


They pack a punch. A couple of 18650 Li-Ion cells are small and light
weight yet can easily power a 10W set of LEDs for over an hour. That
would rival the illumination of a serious truck head lamp.

http://www.amazon.com/3000mAh-Rechar.../dp/B004LHFU62

One does not need that much power all the time, for most of the ride
2-3W will be fine. But it sure helps to switch to full power high beam
during a gnarly section of trail for just a few minutes. Or when a car
driver is about to screw up right in front of you.


But unless you *REALLY* know your electronics - its advisable to buy
manufactured charging equipment!


Oh yeah, and once a Li-Ion has gone exotherm you may not be able to get
the fire put out. It is very tricky to safely charge them when they are
in series for a higher voltage.

--
Regards, Joerg

http://www.analogconsultants.com/

James wrote:
On 31/08/14 03:07, Joerg wrote:
James wrote:
On 30/08/14 02:06, Joerg wrote:
James wrote:


This then.. http://www.starbike.com/en/son-edelux-2-led-front-lamp/


Seems to come without bracket. They need to offer with bracket. The
light is super expensive as it is (would be over US$200) and then I'd
expect not to have to build any missing stuff myself. Also, I hope that
black ring in back ain't plastic or it won't survive.


You didn't look very far. There's a metal bracket to attach it to your
bars. All nice and smooth so you don't cut for knee as you fly over the
bars, etc.


Got a link?


I don't know why I bother. It was on display on the link above.

http://www.starbike.com/en/son-schmi...dlight-holder/


I saw that but it looks a bit weak. What I meant is something more
serious, like this:

http://www.aliexpress.com/item/Bike-...FVGTfgodr74ABQ

But one where the light can be mounted without the wiry stilts.

--
Regards, Joerg

http://www.analogconsultants.com/

Phil W Lee wrote:
Joerg considered Sat, 30 Aug 2014
10:10:16 -0700 the perfect time to write:

James wrote:
On 30/08/14 02:20, Joerg wrote:
Lou Holtman wrote:
You have to realize that your commute route is far from usual.

Not in the Netherlands but in some parts of the world that is usual :-)

Even in your area it can be. I lived in your country for six years, in
Zuid Limburg. I rode over into Belgium a lot and over there we had lots
of remote and rugged mountainous paths that people used as shortcuts.
Many times I almost cussed my dynamo-driven lights because uphill they
produced so little light that I had to hop off the bike and walk it,
mostly to avoid doing an endo in a pothole that I didn't see.

Was that with a modern LED headlight?

No, bulbs. Regular and halogen. But with LED it's not much better unless
you have a battery because the super-caps only power most lights for 5
mins or so (when the dynamo is out of juice).

In the same situation an incandescent light is even worse though.
LEDs are easily the most efficient light source for bicycle use, so
will always give more light or last longer (or some balance between
the two) for any given power input.
And the cycle generator and LED are a very good match for each other,
because both are nearly perfect constant current devices.
Incandescent lights drop off in output much more as the generator
output or battery voltage falls than LEDs do.


Sure. Still, you need to have something that can supply the electricity
when the dynamo doesn't due to low rpm. And ideally one needs more
anyhow, my goal is 5-10W front and 2W back.

LEDs are very efficient but at the same time their spectral distribution
is such that visibility is poorer for the same lumens from an
incandescent. There is no question that bicycle lighting has to be LED
because technologies such as HID will never make it to bicycles.

--
Regards, Joerg

http://www.analogconsultants.com/

James wrote:
On 31/08/14 03:10, Joerg wrote:
James wrote:
On 30/08/14 02:20, Joerg wrote:
Lou Holtman wrote:


You have to realize that your commute route is far from usual.


Not in the Netherlands but in some parts of the world that is usual :-)

Even in your area it can be. I lived in your country for six years, in
Zuid Limburg. I rode over into Belgium a lot and over there we had lots
of remote and rugged mountainous paths that people used as shortcuts.
Many times I almost cussed my dynamo-driven lights because uphill they
produced so little light that I had to hop off the bike and walk it,
mostly to avoid doing an endo in a pothole that I didn't see.


Was that with a modern LED headlight?


No, bulbs. Regular and halogen. But with LED it's not much better unless
you have a battery because the super-caps only power most lights for 5
mins or so (when the dynamo is out of juice).


Actually it is much better with LED lights. They produce good light at
lower speed, due to the efficacy of the LED compared to halogen. Lumens
per watt for LEDs is many times better.

https://www.led-lighthouse.co.uk/how...-are-led-bulbs


Yes, but LED lumens and incandescent lumens are two very different
things due to spectral distribution. For example, with incandescent I
can somewhat see the sheen of poison oak while I can't with LED light.
And woe to those who pedal through that stuff, very few hours later the
fun begins, with one massive itch.

--
Regards, Joerg

http://www.analogconsultants.com/

Phil W Lee wrote:
Joerg considered Sat, 30 Aug 2014
10:13:04 -0700 the perfect time to write:

wrote:
AMAZING

each new visit to an old search question brings an AVALANCHE of material as here

https://www.google.com/#q=EFFECT+OF+...BICYCLE+WHEELS

I am not concerned about rotating mass but more about suspension
behavior. That becomes less than ideal if the non-suspended side gets
heavier. Goes for pretty much aany kind of vehicle.

If it were that big an issue on a bicycle we wouldn't have disc brakes
though, would we?


Try some of the trails I ride without disc brakes :-)


The vital thing isn't absolute mass but the ratio between sprung and
unsprung mass.
Given that the rider accounts for such an overwhelming majority of the
mass, a few grams added to the hub in return for decent and reliable
lights is generally regarded as a very worthwhile trade-off.
And of course, LEDs are far more resistant to shock and vibration than
filaments.


The rider is suspended mass. I would not mind a hub dynamo and would
tolerate the weight. But it's a lot of cost and effort, well north of
$100 for the part, then it has to be spoked up and of course the old
spokes won't fit. Then you have to get the cable up the fork and past
the stanchions. Ok, one can use the front caliper brake line for that,
maybe. But then you are still stuck with realistically 4-5W max which
won't be enough to supply my dream lights. And if I go through all this
effort to mod and experiment and build in a light system I want 8-10W up
front (with high-beam feature) and 2W in back.

--
Regards, Joerg

http://www.analogconsultants.com/

Phil W Lee wrote:
"Ian Field" considered Sun, 31 Aug
2014 17:06:13 +0100 the perfect time to write:


"Phil W Lee" wrote in message
...
Joerg considered Thu, 28 Aug 2014
12:33:45 -0700 the perfect time to write:

wrote:
not so.....night riders in the park are seen with midlevel systems
both on bike and helmet....good enough for 25 mph on pavement.

25mph on pavement ... yawn

What I meant is something that also holds up at 25mph on a bone-rattling
trail. Like it does on cars. No super-expensive boutiques stuff, regular
affordable gear, just like on cars or motorcycles.
Thing is, the energy budget is far higher on those, as they literally
throw the stuff away (via cooling systems).
On a bicycle, you either have to carry the energy with you in the form
of batteries, or generate it using your own muscle power, so the
energy available is much lower.

There's not much point in carrying batteries big enough for car
lighting on a bicycle in order to be safe at 25mph, if the weight of
the batteries slows you down to 15mph.
Lithium batteries are about as light as batteries get.

But unless you *REALLY* know your electronics - its advisable to buy
manufactured charging equipment!

Even that is not a guarantee of safe charging, as the manufacturers of
everything from cellphones through laptops to aircraft have discovered
to their cost.
And expensive batteries are no guarantee either - does anyone
seriously believe that Boeing used budget class batteries or charging
systems in the 787?
Lithium types of battery pose a hazard due to the nature of the
materials involved, and the safety measures necessary in a harsh
environment almost completely negate the power density advantage.

The brutally harsh environment described by Joerg would not be
conducive to anything delicate or on the bleeding edge.


I have an 18650 Li-Ion cell in my front light right now. Of course I
modded the light a wee bit so the battery does not shake and vibrate any
longer. Works for almost two months now, the longest any light has ever
held up. The only gripe I have is that the switch on the light isn't
robust enough. And I am looking for more lumens than the 200-300 this
light puts out. 1000 lumens would be nice but it has to be almost mil-spec.

--
Regards, Joerg

http://www.analogconsultants.com/

On 01/09/14 02:02, jbeattie wrote:


The deal is that I have never ridden for ten hours in the dark, so
selling me on a super long-lasting light is like selling ice to
Eskimos, who, by the way, would most benefit from dynamos during
winter north of the Arctic Circle.

I've never ridden for that long in the dark either. Never the less, as
I said, on numerous occasions I've been asked to chauffeur a mate home
who's rechargeable battery light has died. Several mates now have up to
three (3) flashing lights on their tail - for redundancy only - as they
can't keep them charged for a 2 hour evening riding.

I have always considered putting a dynamo on my commuter bike, and I
still might do it, but I look at cost and convenience, and I lose
momentum. The cost to get me equivalent brightness (I have a 1400
lumen battery light -- usually run at about 800 lumen) means a
SuperNova E3. I would probably get a SP hub rather than Schmidt
because of the price. Rims, spokes, another disc rotor, my time
building . . . boiled linseed oil (which I need to use up, so that's
not a problem). I suppose I could buy a packaged wheel, but I don't
want the usual junk.

http://www.stkildacycles.com.au/inde...00-hybrid.html

Who knows, I might do it anyway. Then I have to
strip it off when I go CX racing or riding with my CX friends.

For a race, sure, but just for a CX ride, why? It's not like you'd notice.

What
I wold gain is modest for my application -- no nights when I forget
to charge my battery.

But you make 1400 lumens sound so indispensable. How could you consider
not needing to think about recharging as only a modest gain?

I also assume that there is no downside to
dynamo lights, like they don't work in pouring rain (I heard that
complaint about one of the major brand dyno lights).

*Any* electronics such as that used to regulate the current through a
high power LED may be affected by water ingress - regardless of the
power source.

I also assume
fixing a front flat isn't much more complicated (i.e. an easily
removed wire connection).

Correct. The plug/socket arrangement on the hub makes wheel removal
only a couple of seconds longer than normal. Barely measurable.

When it is dark, cold and raining, and my
hands barely work, the less effort the better when I have to fix a
flat.

So little effort, you won't notice.


Don't dis my CAAD 9! Conti 4Seasons and my SKS full length clip-on
fenders . . . it's a fast rain bike. It has good clearance for larger
tires, although nothing like my CX bike, of course. Made in the USA,
and warrantied for life! In fact, it is a warranty replacement, so
it's also a "free" frame (if you ignore the fact that I bought the
original frame in 1989-90).


A mate has one. The paint has failed on the top tube and let salty
sweat in. The aluminium has corrosion under the paint, and the paint
has bubbled, but Cannondale won't replace it because the tube hasn't yet
failed.

--
JS

On 8/31/2014 5:32 PM, Joerg wrote:

The rider is suspended mass. I would not mind a hub dynamo and would
tolerate the weight. But it's a lot of cost and effort, well north of
$100 for the part, then it has to be spoked up and of course the old
spokes won't fit. Then you have to get the cable up the fork and past
the stanchions. Ok, one can use the front caliper brake line for that,
maybe. But then you are still stuck with realistically 4-5W max which
won't be enough to supply my dream lights. And if I go through all this
effort to mod and experiment and build in a light system I want 8-10W up
front (with high-beam feature) and 2W in back.

I notice you consistently state your desires in terms of Watts, not in
terms of lumens, lux, candela, footcandles, visibility distances, beam
quality, etc. I think that's a sign of a potential problem. Watts are
_far_ from the most important measurement standard.

--
- Frank Krygowski

On Sunday, August 31, 2014 3:40:05 PM UTC-7, James wrote:
On 01/09/14 02:02, jbeattie wrote:





The deal is that I have never ridden for ten hours in the dark, so

selling me on a super long-lasting light is like selling ice to

Eskimos, who, by the way, would most benefit from dynamos during

winter north of the Arctic Circle.



I've never ridden for that long in the dark either. Never the less, as

I said, on numerous occasions I've been asked to chauffeur a mate home

who's rechargeable battery light has died. Several mates now have up to

three (3) flashing lights on their tail - for redundancy only - as they

can't keep them charged for a 2 hour evening riding.



I have always considered putting a dynamo on my commuter bike, and I

still might do it, but I look at cost and convenience, and I lose

momentum. The cost to get me equivalent brightness (I have a 1400

lumen battery light -- usually run at about 800 lumen) means a

SuperNova E3. I would probably get a SP hub rather than Schmidt

because of the price. Rims, spokes, another disc rotor, my time

building . . . boiled linseed oil (which I need to use up, so that's

not a problem). I suppose I could buy a packaged wheel, but I don't

want the usual junk.



http://www.stkildacycles.com.au/inde...00-hybrid.html



Who knows, I might do it anyway. Then I have to

strip it off when I go CX racing or riding with my CX friends.



For a race, sure, but just for a CX ride, why? It's not like you'd notice.



What

I wold gain is modest for my application -- no nights when I forget

to charge my battery.



But you make 1400 lumens sound so indispensable. How could you consider

not needing to think about recharging as only a modest gain?



I also assume that there is no downside to

dynamo lights, like they don't work in pouring rain (I heard that

complaint about one of the major brand dyno lights).



*Any* electronics such as that used to regulate the current through a

high power LED may be affected by water ingress - regardless of the

power source.



I also assume

fixing a front flat isn't much more complicated (i.e. an easily

removed wire connection).



Correct. The plug/socket arrangement on the hub makes wheel removal

only a couple of seconds longer than normal. Barely measurable.



When it is dark, cold and raining, and my

hands barely work, the less effort the better when I have to fix a

flat.



So little effort, you won't notice.





Don't dis my CAAD 9! Conti 4Seasons and my SKS full length clip-on

fenders . . . it's a fast rain bike. It has good clearance for larger

tires, although nothing like my CX bike, of course. Made in the USA,

and warrantied for life! In fact, it is a warranty replacement, so

it's also a "free" frame (if you ignore the fact that I bought the

original frame in 1989-90).





A mate has one. The paint has failed on the top tube and let salty

sweat in. The aluminium has corrosion under the paint, and the paint

has bubbled, but Cannondale won't replace it because the tube hasn't yet

failed.

First point last -- maybe the local rep is being stingy. If the paint "failed," that's a warranty issue. I've never had the paint fail on a Cannondale. My only failed paint jobs were custom Imron on steel frames and a powder paint respray on a steel frame which was done by a very reputable company that did OEM for Specialized.

Anyway, I almost bought a SP hub on sale over at Western ($131 USD disc model) which I would build on a Velocity A23 or a DT450, which is cheaper, but I want to try the A23. Go to Danscomp and get spokes for maybe $30, so I'm at about $200 - $200, not too bad. So, I go look at lights (at Universal, because they're within riding distance and cheap): http://www.universalcycles.com/search.php?q=supernova Crap, man . . . $240 USD for an 800 lumen light. The little brother for $195 puts out 305 lumen with a five minute stand time (probably good enough). The deal is my current battery light will do 350 lumens for 10 hours, and I already own it.

More light shopping would be needed. And yes, I do blast my light on my commute because it involves unlighted trail at least 3-4 nights a week, and in pouring rain, 800-1400 lumens doesn't seem that bright. As for charging, sure it would be nice to skip it (and recycling batteries, etc.), but it's not onerous. I've been doing it for a few decades (I've been commuting to the same part of town for 29 years -- 23 to the same building. It's become pretty mechanical). Again, though, I'll look in to it some more.


-- Jay Beattie.

On Sun, 31 Aug 2014 07:48:15 -0700, Jeff Liebermann
wrote:

On Sun, 31 Aug 2014 18:08:39 +0700, John B. Slocomb
wrote:

On Sat, 30 Aug 2014 14:46:03 -0700, Jeff Liebermann
wrote:

On Sat, 30 Aug 2014 10:04:18 -0700, Joerg
wrote:

Head lamps are outright hazardous where I ride. Gets you tangled into a
tree branch in a jiffy and then there's probably going to be a rescue
effort followed by an obituary.

Drivel: I get mildly irritated when some calls the front light a
"head" light, and the rear light a "tail" light. We inherited those
terms from the horse and buggy era. They apply nicely to horses,
donkeys, mules, and other beasts of burden, but not motor or human
powered vehicles. Unless you plan to have your bicycle pulled by one
of these, please use a more appropriate term.

It's also not a "lamp", which implies that something burning is
producing the light. Unless you use fire to illuminate your path,
please use the term "light" instead.

Hmmm... My dictionary translates "Lamp" as "an artificial source of
visible illumination"...

Your definition is somewhat truncated:
https://www.google.com/#q=origin+of+the+word+lamp
a device for giving light, either one consisting of an
electric bulb together with its holder and shade or cover,
or one burning gas or a liquid fuel and consisting of a
wick or mantle and a glass shade.
Do your front or rear lights burn gas or liquid fuel or have a glass
shade?

Yes, truncated as I was addressing only the definition implying the
use of liquid fuel.

However, I can understand the mystery as the word 'or" that you use
above apparently caused the problem. My "American" dictionary
interprets it as:

"OR ~ noun
1. a state in northwestern United States on the Pacific
2. a room in a hospital equipped for the performance of surgical
operations"

--
Cheers,

John B.