Bicycle lighting question

Beam pattern is less of a concern in cycling when you have 700+ Lumens of light to play with...unless you are doing some fast descending where a sharper, automotive cutoff allows better illumination without the hazard of blinding oncoming traffic.

With that said, I DO get oncoming traffic flashing me with their brights. I think its more of an attention thing rather than blindness from my single headlight.

Now on the cost of HID lights, the bulb alone is $150 direct from Welch Allen, the manufacturer of most small HIDs. Throw in the ballast and you are well over $200 and this is without the battery, cables and charger. These items cost $40 minimum.

Weisse Luft said:

Beam pattern is less of a concern in cycling when you have 700+ Lumens
of light to play with...

But why pay for huge numbers of lumens - in initial cost, battery life,
lamp expense, etc - if you can do as well or better with far fewer
lumens focused into a properly shaped beam?

There is nothing about a modern bicycle which is so crude as the optics
of an expensive bike light. No other road vehicle puts up with such bad
optics.

--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu]

quote='Frank Krygowski'Weisse Luft said:

Beam pattern is less of a concern in cycling when you have 700+ Lumens
of light to play with...

But why pay for huge numbers of lumens - in initial cost, battery life,
lamp expense, etc - if you can do as well or better with far fewer
lumens focused into a properly shaped beam?

There is nothing about a modern bicycle which is so crude as the optics
of an expensive bike light. No other road vehicle puts up with such bad
optics.

--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu][/QUOTE]

Its all manufacturing costs. Making a precise, linear cutoff reflector in mass requires great engineering and precise machining. For automotive illumination where a desired light is required yet the lumen/wattage is strictly limiited. The cycling market is not large enough to support such expenses without marketing points like HID efficiency so the latter is used in place of engineering. There is one cycling light manufacturer who has a custom made reflector but alas, its NOT of the sharp cutoff variety.

Oh, on a purely subjective matter, the "wasted light" from the conical beam lights still has a good use, that being visibility of the cyclist to motorists.

If you are interested in small HID components, the leading manufacturer is Welch-Allyn, not Welch Allen. They have web presence plus a host of other technical information.

Frank Krygowski said:

The bike lights I've got from the 1960s all at least _try_ to shape
the beam to the task. Those from the 1970s do a very good job of
putting
the light where it's really needed. And that remains true _until_ you
look at the super-expensive NightSun offerings and their MR-11 or
MR-16 kin. Suddenly, the optical technology regresses to the level
of 1900!

I wonder if you've used such lights. My Sunsport, with a 5W MR11 narrow spot,
has a beam pattern practically identical to the much-praised Cateye Micro. The
center spot is the same size and shape, but brighter. The spillover is the same
size (area), but round instead of square. To my eye, the ratio of spillover to
focused light is about the same. So there's no real difference in these two
lights' beam patterns. I know this because I use these lights together all the
time. It's my standard night setup.

BTW, why have I never seen your name on the Bikecurrent mailing list? You seem
so passionate about this issue.

Matt O.

The lack of efficiency in bicycle lights is no where near the lack of efficiency in present day computer code, especially if the code is from a certain company in Redmond, Washington. But the reason for tolerance of both inefficiencies is technology.

Where batteries back in 1900 were heavy, expensive and difficult to handle, modern NiMH or LiPolymer have power densities that make a 4 hour duration under 500 grams possible. And HID/LED further that duration.

Sure, one could make a better reflector for a HID but since the smallest practical HID, that being a 10 Watt, provides plenty of light for all but insane downhill use with the standard parabolic reflector, the cost/benefit ratio is too high.

Lithium secondary cells are the next big step. Unfortunately, there are significant hazards associated with this chemistry. While the weight is 1/2 to 1/3 that of the best NiMH, the secondary packaging must assure a safe pack in the event of damage. They are coming.

Quoted message said:

I wonder if you've used such lights. My Sunsport, with a 5W MR11 narrow spot,
has a beam pattern practically identical to the much-praised Cateye Micro. The
center spot is the same size and shape, but brighter. The spillover is the same
size (area), but round instead of square. To my eye, the ratio of spillover to
focused light is about the same. So there's no real difference in these two
lights' beam patterns. I know this because I use these lights together all the
time. It's my standard night setup.

I sure like mr16 better though. I can get the whole lane lighted with the same
wattage as mr11 with 1/2 or less the beam coverage. I can get away with a 12
degree beam. now when I crank up the power I can use a 17 degree beam and really
light the road. but it drains the batteries pretty quickly.

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.

It's a really interesting point. As I posted above, I found a really fine generator setup (Schmidt dynohub and Schmidt headlamp). While of course it's not even close to the overall power of a NiteRider, what is truly remarkable IMHO is how the designers have CAREFULLY designed a reflector to cast a narrow but remarkably bright beam given that they have only 3W to work with. Just amazing. It's so utterly precisely laid out on the road ahead, and like most generator lights they've designed in some "side windows" of illumination -- i.e. a few points of light down each side. Within the narrow beam, surprising as it may sound, it's just about as bright as the NiteRider, even though the latter is a much much wider beam. My point is, supporting Frank's, if the NiteRider, Cateye, etc. guys would take this much care in designing their reflectors, you'd simply get a whomping amount of light. The Schmidt setup is too narrow for offroad use, so I'm not advocating that they _copy_ the design, just that they take an equivalent amount of care designing a reflector.

quote='Frank Krygowski'Weisse Luft said:

Beam pattern is less of a concern in cycling when you have 700+ Lumens
of light to play with...

But why pay for huge numbers of lumens - in initial cost, battery life,
lamp expense, etc - if you can do as well or better with far fewer
lumens focused into a properly shaped beam?

There is nothing about a modern bicycle which is so crude as the optics
of an expensive bike light. No other road vehicle puts up with such bad
optics.

--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu][/QUOTE]

Quoted message said:

Frank Krygowski said:

It seems odd to me; in every other aspect of cycling, people try for
maximum efficiency, and with good reason! Why is lamp design so
ham-fisted?

Weisse Luft said:

...the cost/benefit ratio is too high.

I think Weisse hit the nail on the head. I was looking at the beam from
my NiteRider last night, and I would guesstimate that 80% of the light
was being used appropriately. So that's 20% of the energy wasted. If I
were to reclaim that 20%, I could do a few things: 1) get 25% more
battery life by keeping the existing battery, 2) reduce my battery
weight by something less than 20% by keeping the battery life constant,
or 3) maybe I could use an 8W bulb rather than 10W. None of these
options is worth a great deal of money to me, so NiteRider is not going
to get a lot of return on investment if they design a better reflector.

If the NiteRider beam was wasting half of its light, I'd say that the
payback would warrant the investment on the part of NiteRider. Doubling
battery life would be very beneficial, and going from 10W to 5W would
enable the use of some generators.

--
Dave
dvt at psu dot edu

Weisse Luft said:

Frank Krygowski said:

But why pay for huge numbers of lumens - in initial cost, battery
life,
lamp expense, etc - if you can do as well or better with far fewer
lumens focused into a properly shaped beam?

There is nothing about a modern bicycle which is so crude as the
optics
of an expensive bike light. No other road vehicle puts up with such
bad
optics.

Its all manufacturing costs. Making a precise, linear cutoff reflector
in mass requires great engineering and precise machining. For
automotive illumination where a desired light is required yet the
lumen/wattage is strictly limiited. The cycling market is not large
enough to support such expenses without marketing points like HID
efficiency so the latter is used in place of engineering.

Absolutely false!

Check out any inexpensive Cateye light from ten years ago - anything
they sell that costs less than $20. You'll find a faceted lens that
shapes the beam into a very efficient rectangle. Some models add
partial-sphere reflectors in front of the bulb, to redirect waste light
and further improve efficiency.

They do this with lights that sell for $11.95. There's no reason it
can't be done with lights that sell for $50 to $500.

There is one

Quoted message said:

cycling light manufacturer who has a custom made reflector but alas, its
NOT of the sharp cutoff variety.

Oh, on a purely subjective matter, the "wasted light" from the conical
beam lights still has a good use, that being visibility of the cyclist
to motorists.

I understand that, but the amount of light necessary to make a cyclist
visible to motorists is easily provided by something consuming less than
3 watts. And even if you feel that's wrong, what's the case for sending
light upward, toward the stars?

Quoted message said:

If you are interested in small HID components, the leading manufacturer
is Welch-Allyn, not Welch Allen. They have web presence plus a host of
other technical information.

Personally, I'm not interested in super-expensive overkill. I _would_
be interested in any data that actually measures cyclist conspicuity.
The only such test data I've been able to find (sorry, it's at my other
computer now) showed motorists recognizing cyclists from hundreds of
feet away, when the cyclists had only a 2-C cell leg light!

--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu]

Matt O'Toole said:

Frank Krygowski said:

The bike lights I've got from the 1960s all at least _try_ to shape
the beam to the task. Those from the 1970s do a very good job of
putting
the light where it's really needed. And that remains true _until_ you
look at the super-expensive NightSun offerings and their MR-11 or
MR-16 kin. Suddenly, the optical technology regresses to the level
of 1900!

I wonder if you've used such lights. My Sunsport, with a 5W MR11 narrow spot,
has a beam pattern practically identical to the much-praised Cateye Micro. The
center spot is the same size and shape, but brighter. The spillover is the same
size (area), but round instead of square. To my eye, the ratio of spillover to
focused light is about the same. So there's no real difference in these two
lights' beam patterns. I know this because I use these lights together all the
time. It's my standard night setup.

I used to have a Cateye Micro, but I gave it away. Personally, I prefer
the optics of the several generator lamps I have. I also preferred the
optics in the older Cateye lights - the low-powered ones that run on two
C cells.

Note, though, that I wasn't satisfied with the total light output of
those Cateye lamps. It was the optics that I liked.

Cateye claimed the Micro was brighter, and it may have been - that is,
the complex "luminux" reflector shape may have "eaten" less light than
the fresnel-like front lens on the other Cateyes. I never got a chance
to run similar bulbs with different optics to do a direct comparison.

Quoted message said:

BTW, why have I never seen your name on the Bikecurrent mailing list? You seem
so passionate about this issue.

:-) Because I already waste too much time in these forums!

Seriously, I was a bikecurrent subscriber some years ago, and
occasionally I browse the archives. But I can't afford the time to stay
.... um, current with that list.

--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu]

Matt O'Toole said:

I wonder if you've used such lights. My Sunsport, with a 5W MR11 narrow spot...

I forgot to mention, I have an MR-11 based light (I forget the wattage
now - I think it was 10 watts) and I've ridden quite a lot with a guy
that uses an MR-11 system, by Vistalight IIRC. I find it very
unimpressive, given its cost and power requirements.

I also have an old 4xx-series Vistalight, 6 watts with a focusable beam.
While I don't like the fact that the beam is a cone (versus rectangle)
it provides more light than I ever seem to need.

I rarely use these rechargeables. I prefer my always-ready generator light.

--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]

Quoted message said:

Seriously, I was a bikecurrent subscriber some years ago, and
occasionally I browse the archives. But I can't afford the time to stay
... um, current with that list.

it's not usually too busy. but most of the info is way past me (G)

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.

On 2004-11-28 15:52:38 -0800, [email hidden] (Chris Zacho "The

Wheelman') said:

(Robert Haston) said:

HID lights require ballast circuits and are
very precise instruments that are hard to
manufacture. Because of this they are
expensive and fragile.

Quoted message said:

LED technology is really taking over. 3
watt emitters which are much more
efficient than halogens cost less than
$15. I bought two 3 watt flashlights from
elektrolumens for $40 each. They have
voltage regulators and run about an hour
on two NiMH AAs, which are easy to
swap out.

How bright are they though? Granted, the six red LED's on my CatEye are
are dazzling. It isn't made for lighting the road. Very few are the
street lamps here in rural South Carolina...

How bright is an HID, compared to an LED?!

You REALLY haven't seen them together, have you? The typical HID light
these days (I use the Lights & Motion HID lights -- I've had excellent
results with them) often get cars to blink their brights at me. And
they ALWAYS wait instead of making a right in front of you... they
think you're a car rather than bike, so the typical "let's just pull
out in front of this slow guy on a bike" mentality doesn't apply.

It's really.. not even close.

As for the price... yes $400 is a lot for a light. I found mine at
SuperGo on sale (20% off of 20% off), back in September... cost about
$280. And it's got a nice NiMH battery along with the ballast and all
the parts. No way I'm willing to spend 10 hours engineering a
self-built light for some janky piece of [censored] 3" diameter light bucket
the home brewers like to beam about.

Bill Lloyd said:

On 2004-11-28 15:52:38 -0800, [email hidden] (Chris Zacho "The

Wheelman') said:

(Robert Haston) said:

HID lights require ballast circuits and are
very precise instruments that are hard to
manufacture. Because of this they are
expensive and fragile.

Quoted message said:

LED technology is really taking over....

How bright is an HID, compared to an LED?!

You REALLY haven't seen them together, have you? The typical HID light
these days (I use the Lights & Motion HID lights -- I've had excellent
results with them) often get cars to blink their brights at me. And
they ALWAYS wait instead of making a right in front of you... they think
you're a car rather than bike, so the typical "let's just pull out in
front of this slow guy on a bike" mentality doesn't apply.

It's really.. not even close.

Not good enough! Not good enough!

I'm saving for a thermonuclear-powered Space Shuttle landing light.
From the ride reports I've read about these things, motorists don't
even have time to blink their brights at you, because they're
instantaneously and totally blinded!

Not to worry, though; tests have shown that the right turning motorists
stop immediately even though they can't see. Seems it's a panic
reaction caused by the blindness and the intense heat. Maybe the paint
fumes boiling off their hood also have an effect - we can't be sure.
Buy hey, it works!!

Only one caution: Be sure to mount this baby far out ahead of your
front wheel (so the stray unfocused light doesn't cook your tire) and do
NOT, repeat: do NOT point it at the ground! Softened asphalt increases
your rolling resistance! You've been warned!

Quoted message said:

As for the price... yes $400 is a lot for a light.

Oh, not a bit! There's no reason to pay less for your headlight than
you did for your bike - and car, and home. Priorities, man!

--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu]

Chris Zacho The Wheelman said:

Back when I was commuting to work daily and riding double centuries
every year, I plopped down the virtual cash on the necessity of an ultra
bright lighting system (NightSun). Even then, the thought of paying
$200+ for a bicycle light was more than slightly irritating. Automobile
headlights don't cost that much (and are much brighter to boot (yeah, I
know thy have access to more power!)). Even the "complete" headlights
(bulb and reflector) are 60% cheaper. So why do bicycle lights cost so
much?

Now we have the HID (arc) lights going for TWICE the price! I love the
idea of getting 30+ watts for 4+ hours run time on one charge, but I
still have to wonder at the price. Just what IS it that makes bike
lights so expensive?

Besides the fact that there isn't any less expensive competition from
Auto-Zone or X-mart, I mean.

Well, that's part of it; it's a specialized niche with lower economy of
scale and smaller market and distribution channels.

For HID, the bulb itself is a large part of the cost. the HID capsule
is fused quartz, which is difficult to work with. The 10W size used in
bike lights has an extremely small capsule and due to this and the small
number of units, are blown by hand. Blowing a millimeter-sized capsule
out of molten quartz is an uncommon skill. It really is pushing the
limits of the technology compared to automotive HID, which is expensive
enough itself.

Despite the cost I give a big thumbs up to my Light & Motion HID. I do
not consider it overkill. While lower power lights with tighter beams
are sufficient to see the road, I have noticed a real and dramatic
difference in the response of motorists. It's one thing to say that a
light is visible from 1 or 2 miles (hell, a candle is visible from a
mile) and quite another for a motorist to actually recognize it and be
concerned about right of way. The HID gets their attention in a way
that other lights simply do not. Not that it is unfairly or blindingly
bright. I have used it for hundreds of hours and do not have cars
flashing their highbeams at me. I have also encountered other riders
with similar lights while cycling as well as driving. They are not
rudely bright. But bright enough. And, this is in measure due to the
significant sidespill light which others refer to as wasteful. I do not
consider it to be so as I am convinced that it is the key to the
visibility I now have with motorists. I have used 10watt halogen
systems which just did not get these results. The other benefit to the
more expensive systems is the use of smart chargers and better battery
chemistries which allow a far greater useful life for the battery packs
than the old wall-wart chargers that would fry the batteries unless
scrupulously tended. But bottom line, I feel the price is worth it for
the added safety of fewer dangerous encounters with motor vehicles. For
someone who must ride in darkness in busy areas, this is a value that
should be carefully considered.

Bike generator systems do have advantages, and I may end up building a
wheel around a generator hub, using it to power a taillight and a
standby headlamp in case the HID goes out or I outride the batteries.

LED technology promises to overtake HID for this task at some point
though not quite there yet. The only complaint I have with HID other
than cost is that the output spectrum is heavily skewed and not quite as
useful as you'd expect given the intensity. Colors are washed out and
road glass does not sparkle. I'm hoping that LEDs will be able to
provide both the quantity and quality of light as they improve, along
with less fragility although from what I've seen, pushing the technology
hard enough to get the light output at this point results in emitter
life that is no better than MTBF for the 10w HID at this point --
several hundred hours. Also, the blue intensity of HID is probably also
a factor in its "noticeability", so.... Anyway, I'm rambling.

Nubo said:

LED technology promises to overtake HID for this task at some point
though not quite there yet.

I agree, this is where the next improvement will come. And I'm betting
it will be soon.

.... from what I've seen, pushing the technology

Quoted message said:

hard enough to get the light output at this point results in emitter
life that is no better than MTBF for the 10w HID at this point --
several hundred hours.

Are you saying a HID bulb is good for only several hundred hours? I
wasn't aware of that. If true, that's certainly a downside!

Also, the blue intensity of HID is probably also

Quoted message said:

a factor in its "noticeability",

If the color is a sufficient benefit, it can be achieved in many ways.

--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]

Nubo said:

LED technology promises to overtake HID for this task at some point
though not quite there yet.

If you know anything about semiconductor physics, you'll understand why
this is not likely to happen for a long time, if ever. High power LEDs
have the same issues as over-voltaging conventional lamps, the excessive
heat results in a short life. However a conventional lamp is cheap, a 5W
LED is very expensive.

The best hope for LEDs is an array of lower power LEDs, but they don't
lend themselves well to focusing into a coherent beam.

The HID technology is sound, you get better efficiency with lower
current and higher voltage.

LEDs are great for "being seen" lights, where it isn't necessary to
create a focused beam.

Frank Krygowski said:

Are you saying a HID bulb is good for only several hundred hours? I
wasn't aware of that. If true, that's certainly a downside!

The rated life of the bulb in the L&M HID light is 700 hours, iirc. I
understand that the various manufacturers of HID bike lights all source
their bulbs from Welch Allyn, so they are probably comparable.

700 hours is not quite as bad as it sounds. The over-voltaged halogen
bulbs typical in halogen bike-light applications have lifetimes that are
closer to only 200 hours. And whereas a filament bulb can die early
from shock or vibration, the HID is more tolerant and more likely to run
to its rated life.

Steven M. Scharf said:

If you know anything about semiconductor physics, you'll understand
why this is not likely to happen for a long time, if ever. High power
LEDs have the same issues as over-voltaging conventional lamps, the
excessive heat results in a short life. However a conventional lamp is
cheap, a 5W LED is very expensive.

The best hope for LEDs is an array of lower power LEDs, but they don't
lend themselves well to focusing into a coherent beam.

I've seen an example of a homebrew bicycle light using three 3W LED
emitters, with collimating optics for each. This was pretty close to
what I'd consider a worthy competitor to the HID I'm using now, judging
from photos. The light seemed bright enough and color rendition
appeared good, though again based only on a photograph. The other nice
thing would be the redundancy of 3 emitters, where sudden failure of one
does not put you in the dark.

Nubo said:

Frank Krygowski wrote:

Quoted message said:

Quoted message said:

Are you saying a HID bulb is good for only several hundred hours? I
wasn't aware of that. If true, that's certainly a downside!

The rated life of the bulb in the L&M HID light is 700 hours, iirc. I
understand that the various manufacturers of HID bike lights all
source their bulbs from Welch Allyn, so they are probably comparable.

700 hours is not quite as bad as it sounds.

Well, you can do the math for yourself -- how often will you be replacing lamps,
how much will this cost, and is it acceptable *to you.*

Quoted message said:

The over-voltaged halogen
bulbs typical in halogen bike-light applications have lifetimes that
are closer to only 200 hours.

It depends. Overdriven halogens have a shorter life, but are more prone to
premature failure too. Filaments can break from shock loads, and the hotter
they are, the weaker. This is why Nightsun stuck to rated voltage with their
original systems. Their customers were doing overnight rides in the CA deserts,
where reliability is paramount.

Second, bulb life varies a lot. There's no telling just how overdriven these
bulbs are. Each bike light manufacturer makes its own call about bulb life vs.
brightness. Even generic MR lamps vary from 2-4000 hours at their rated
voltage, and that's before reducing their life by a factor of 10 by overdriving
them 10-20%. There are significant quality differences too.

Quoted message said:

And whereas a filament bulb can die
early from shock or vibration, the HID is more tolerant and more
likely to run to its rated life.

Probably. However, a 4000 hour halogen lamp at its rated voltage is quite shock
resistant.

Here's an illustrative design dilemma. For a "high beam" in a typical two lamp
offroad system, you could use a 35W lamp, or an overdriven 20W one. Both give
about the same amount of light, with the overdriven lamp being more efficient.
But -- do you want to risk losing your high beam during a rough, high speed
downhill? And since it's only being used, say, 10% of the time (on the high
speed sections), does it really matter if it's less efficient? Might it be
better to use the less efficient, but more reliable lamp?

Matt O.