Cycling Equipment · Public discussion

LED headlights?

Started by David L. Johnso · · Last activity · 127 posts · 16,355 views

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Cycling Equipment
Published
11 January 2004
Last activity
21 January 2004
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David L. Johnso
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  1. I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the moment
    I use a 15W Nightrider, but am interested in something that would last longer and still have
    enough light.

    Are there LED lights that really do the job? How many watts would it take?

    --

    David L. Johnson

    __o | This is my religion. There is no need for temples; no need for _`\(,_ | complicated
    philosophy. Our own brain, our own heart is our (_)/ (_) | temple. The philosophy is kindness.
    --The Dalai Lama

  2. David L. Johnson said:


    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the moment
    I use a 15W Nightrider, but am interested in something that would last longer and still have
    enough light.

    Are there LED lights that really do the job? How many watts would it take?

    That would be nearly enough light if it's not generating heat; but the LED reputation for lasting
    a long time comes from its not drawing much current, which until now has meant not much light
    either. So waiting for LEDs to throw out more light so as to get a longer runtime is doomed to
    failure from the start, except for some constant factor from LED efficiency, say two, from not
    generating heat as well.

    Nearly enough light if like you are, like me, satisfied with 3w halogen from two Cateye HL-
    1500's, that is.
    --
    Ron Hardin [email hidden]

    On the internet, nobody knows you're a jerk.

  3. David L. Johnson said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the moment
    I use a 15W Nightrider, but am interested in something that would last longer and still have
    enough light.

    Are there LED lights that really do the job?

    I don't have direct experience with riding with LED headlights. I use a Schmidt generator hub and a
    Lumotec Oval lamp and find that perfectly adequate for riding all night long.

    At PBP this year I saw many people using LED lights, most of which cast a very bright and very
    narrow beam. Many people also had *no* clue about how to mount and aim a headlight, putting it above
    the bars and pointing it at the ground right in front of the wheel. The light appeared adequate in
    brightness but too narrow in focus for my tastes.

    A to B Magazine did some comparison tests with night photos comparing beam patterns; you can
    check their Web site although I don't think the article itself is posted. You could get it as a
    back issue.

    atob.org.ukatob.org.uk

    There's another Web site with night photos that you can compare lights.

    fa-technik.adfc.devergleich.htm

    Peter White's Web site also has some comparisons between lights.

    peterwhitecycles.comlightingsystems.htm

  4. David L. Johnson said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the moment
    I use a 15W Nightrider, but am interested in something that would last longer and still have
    enough light.

    Are there LED lights that really do the job? How many watts would it take?

    The Cateye EL-300 passes British Standards for front lights and is wildly popular over here.
    Personally I don't think it throws a real beam, so I'll stick with my dynamo for now.

  5. "David L. Johnson" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the moment
    I use a 15W Nightrider, but am interested in something that would last longer and still have
    enough light.

    Are there LED lights that really do the job? How many watts would it


    take?

    Quoted message said:


    --

    David L. Johnson

    I may have been that guy. The light is the Planet Bike Super Spot
    (planetbike.comfeature.html) at ~$35. Performance was selling it for ~$30 as an intro
    price. A call to Planet Bike confirmed that they use the Lumileds Luxeon Star 1W part. They say
    price is the only thing keeping them from using the higher output Luxeon Star parts. One of the
    frustrating things about the rating of bike lights is that everyone seems to quote watts as the
    yardstick. Watts tells you how much power the unit consumes, it doesn't tell you how much light (in
    lumens) is output. I believe that LED lights have higher efficiency as they produce more lumens/watt
    than your standard halogen type bulb so using watts isn't a good unit of comparison. For the future,
    Lumileds propaganda talks about output going from about 20 lumens/watt to around 50 lumens/watt in a
    couple of years so the future of LED lighting for bicycles might be promising. The other challenge
    in LED light design seems to be the optics; standard halogen reflectors don't seem to be optimal. I
    currently have a 1W LED flashlight which is pretty amazing, but I don't believe it has enough light
    for cycling at any significant speed. I have one of these Planet Bike units on order, and plan to
    modify it using the 3W Luxeon Star if possible ($13 from www.elekrolumens.com). If it works out,
    I'll post my findings.

  6. Tim McNamara said:

    At PBP this year I saw many people using LED lights, most of which cast a very bright and very
    narrow beam. Many people also had *no* clue about how to mount and aim a headlight, putting it
    above the bars and pointing it at the ground right in front of the wheel. The light

    So where is one supposed to put it? As low as possible?

    --

    QUIPd 1.02: (120 of 679) -> One thing a computer can do that most humans can't is be sealed -> up in
    a cardboard box and sit in a warehouse. --Jack Handey
    ##4619 #'Mandrake Linux.'

  7. David L. Johnson said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the moment
    I use a 15W Nightrider, but am interested in something that would last longer and still have
    enough light.

    Are there LED lights that really do the job? How many watts would it take?

    The 1W LED mentioned was almost certainly the Lumileds Luxeon, the uncontested heavy hitter in LEDs
    for illumination at this time. Luxeon LEDs come in 3W and 5W variants as well, though the 5W white
    version is extremely short-lived.

    lumileds.comlumileds.com

    The power efficiency of LEDs themselves is not all that impressive; maybe twice as high as
    incandescent and improving steadily. There are other advantages to LED illumination, though. Light
    color and beam quality are usually superior to incandescents, and LEDs maintain the same color
    output as they diminish in brightness from tired batteries.

    Also, since LEDs are rather particular about supply voltage, they are often paired with voltage-
    regulating electronics. These electronics can deliver the side benefit of sucking every available
    drop of juice from the batteries, which in effect is the same as delivering higher power efficiency.

    Furthermore, the rated life of most LEDs is on the order of hundreds of times that of small
    incandescent bulbs, and they are for practical purposes shock- and vibration-proof.

    With LEDs, colored light is just as efficient to make as white light, if not more so. This
    characteristic has already been exploited to cyclists' benefit by the provision of red blinky lights
    that can be left on for days or weeks between battery changes. But red and amber LEDs could easily
    be included in an array of mostly white ones, for the express purpose of selectively lighting up red
    and amber reflective markers with a "white" headlight. High intensity true green, blue, and
    violet/blacklight LEDs are also available, and some systems "build" white light by mixing 3 or more
    pure colors.

    The LED Museum has lots of information about LED lighting and available products:
    ledmuseum.home.att.netledmuseum.home.att.net

    Candlepower Forums gives a unique look into the esoteric ways of flashlight geeks:
    candlepowerforums.compostlist.php

    Chalo Colina

  8. David L. Johnson wrote ...

    Quoted message said:


    Are there LED lights that really do the job? How many watts would it


    take?

    The 3 LED types by Cateye or Smart in flash mode are excellent to allert cars and other riders -
    reports back are that they are extraordinarily attention getting - rather akin to a camera flash
    attracting attention.

    When they are in constant mode the light is softer but more widespread (not unlike a flourosecent
    light) than the typical 4x AA cell lights with 2 to 3 w halogen bulb - good enough to use in a bunch
    on roads where there are ok street lights.

    The great thing about the small LEDs is that they take up no room, have no cables, 2 x AA batteries
    last for months (a whole winter for me) and they can stay on the bars constantly for the occasion
    you get caught out and feel the need for a front light (tunnels are an example).

    For a dark road of any length, serious wattage is required (10 to 15w) and current LED's will not
    enable you to see the things on the road you really do need to see - but I think the high wattage,
    high weight solution is a need for particular routes.

    There are also single white LED's in a small plastic case about the size of 10c piece with elastic
    straps that folk put on the front forks in flash mode - very little benefit IMHO - but they are
    great on a key ring and pretty effectively replace the need for a convenience torch when walking.

    I also have the impression that development of LEDs if far from finished.

    best, Andrew

    Quoted message said:


    --

    David L. Johnson

    __o | This is my religion. There is no need for temples; no need for _`\(,_ | complicated
    philosophy. Our own brain, our own heart is our (_)/ (_) | temple. The philosophy is kindness.
    --The Dalai Lama

  9. I would say that for routes you are familiar with, the EL300 is fine, especially if they are lit at
    all or if there's moonlight about. It won't cut it for dark, unfamiliar routes in the dead of night.
    It does last a long time on NiMH recharageable AAs. I recharge my batteries after about 15 hours of
    use an notice no deteioration of the beam by then. From what I understand it can go a while longer
    that that.

    I'm waiting for is a good LED light designed to work with dynamos. That would be cool.

    -Bruce-

    "Zog The Undeniable" <[email hidden]> wrote in message "]news:[email hidden]...

    Quoted message said:
    David L. Johnson said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or


    so).

    Quoted message said:
    Quoted message said:

    Now, 1 watt does not seem like much. At the moment I use a 15W Nightrider, but am interested in
    something that would last longer and still have enough light.

    Are there LED lights that really do the job? How many watts would it


    take?

    Quoted message said:


    The Cateye EL-300 passes British Standards for front lights and is wildly popular over here.
    Personally I don't think it throws a real beam, so I'll stick with my dynamo for now.

  10. rosco' reverse-the-following'ocsor_g'@hotmail.com said:

    I have one of these Planet Bike units on order, and plan to modify it using the 3W Luxeon Star if
    possible ($13 from www.elekrolumens.com). If it works out, I'll post my findings.

    You'll have to boost the voltage, either by using a higher-voltage battery string, or by using a step-
    up DC-DC converter. Lithium ion rechargeable cells deliver a voltage compatible with direct drive
    for most 3W Luxeons.

    Chalo Colina

  11. "rosco" <reverse-the-following"ocsor_g"@hotmail.com> wrote in message news:<[email hidden]>...

    Quoted message said:

    "David L. Johnson" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the
    moment I use a 15W Nightrider, but am interested in something that would last longer and still
    have enough light.

    Are there LED lights that really do the job? How many watts would it


    take?

    Quoted message said:


    --

    David L. Johnson

    I may have been that guy. The light is the Planet Bike Super Spot
    (planetbike.comfeature.html) at ~$35. Performance was selling it for ~$30 as an intro
    price. A call to Planet Bike confirmed that they use the Lumileds Luxeon Star 1W part. They say
    price is the only thing keeping them from using the higher output Luxeon Star parts. One of the
    frustrating things about the rating of bike lights is that everyone seems to quote watts as the
    yardstick. Watts tells you how much power the unit consumes, it doesn't tell you how much light
    (in lumens) is output. I believe that LED lights have higher efficiency as they produce more
    lumens/watt than your standard halogen type bulb so using watts isn't a good unit of comparison.
    For the future, Lumileds propaganda talks about output going from about 20 lumens/watt to around
    50 lumens/watt in a couple of years so the future of LED lighting for bicycles might be promising.
    The other challenge in LED light design seems to be the optics; standard halogen reflectors don't
    seem to be optimal. I currently have a 1W LED flashlight which is pretty amazing, but I don't
    believe it has enough light for cycling at any significant speed. I have one of these Planet Bike
    units on order, and plan to modify it using the 3W Luxeon Star if possible ($13 from
    www.elekrolumens.com). If it works out, I'll post my findings.

    One final point a standard LED has a beem pattern of 8 to 12 degrees this is about perfect for a
    headlight, not a be seen light. In order to make a be seen light the beem pattern needs to be wider.
    In a colored LED they add a pigment to the epoxy lens. This does not work in a white LED they have
    to add glass beads to the epoxy lens this adds two dollars to each LED. Is any manufactuers listing?

  12. "rosco" <reverse-the-following"ocsor_g"@hotmail.com> wrote in message news:<[email hidden]>...

    Quoted message said:

    "David L. Johnson" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the
    moment I use a 15W Nightrider, but am interested in something that would last longer and still
    have enough light.

    Are there LED lights that really do the job? How many watts would it


    take?

    Quoted message said:


    --

    David L. Johnson

    I may have been that guy. The light is the Planet Bike Super Spot
    (planetbike.comfeature.html) at ~$35. Performance was selling it for ~$30 as an intro
    price. A call to Planet Bike confirmed that they use the Lumileds Luxeon Star 1W part. They say
    price is the only thing keeping them from using the higher output Luxeon Star parts. One of the
    frustrating things about the rating of bike lights is that everyone seems to quote watts as the
    yardstick. Watts tells you how much power the unit consumes, it doesn't tell you how much light
    (in lumens) is output. I

    Bless you! i was so tired of reading the this watts vs that watts by the "expert" in the other evil
    mindless lighting thread.

    Quoted message said:

    believe that LED lights have higher efficiency as they produce more lumens/watt than your standard
    halogen type bulb so using watts isn't a good unit of comparison. For the future, Lumileds
    propaganda talks about output going from about 20 lumens/watt to around 50 lumens/watt in a couple
    of years so the future of LED lighting for bicycles might be promising. The other challenge in LED
    light design seems to be the optics; standard halogen reflectors don't seem to be optimal. I
    currently have a 1W LED flashlight which is pretty amazing, but I don't believe it has enough
    light for cycling at any significant speed. I have one of these Planet Bike units on order, and
    plan to modify it using the 3W Luxeon Star if possible ($13 from www.elekrolumens.com). If it
    works out, I'll post my findings.

    (if ya don't know) heat is the killer. here is Willie Hunt's solution for the 5-W Luxeon Star (i
    hope it goes under the HBs): <cs.indiana.eduDSCN4177.JPG

  13. "rosco" <reverse-the-following"ocsor_g"@hotmail.com> wrote in message news:<[email hidden]>...

    Quoted message said:

    "David L. Johnson" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the
    moment I use a 15W Nightrider, but am interested in something that would last longer and still
    have enough light.

    Are there LED lights that really do the job? How many watts would it


    take?

    Quoted message said:


    --

    David L. Johnson

    I may have been that guy. The light is the Planet Bike Super Spot
    (planetbike.comfeature.html) at ~$35. Performance was selling it for ~$30 as an intro
    price. A call to Planet Bike confirmed that they use the Lumileds Luxeon Star 1W part. They say
    price is the only thing keeping them from using the higher output Luxeon Star parts. One of the
    frustrating things about the rating of bike lights is that everyone seems to quote watts as the
    yardstick. Watts tells you how much power the unit consumes, it doesn't tell you how much light
    (in lumens) is output. I believe that LED lights have higher efficiency as they produce more
    lumens/watt than your standard halogen type bulb so using watts isn't a good unit of comparison.
    For the future, Lumileds propaganda talks about output going from about 20 lumens/watt to around
    50 lumens/watt in a couple of years so the future of LED lighting for bicycles might be promising.
    The other challenge in LED light design seems to be the optics; standard halogen reflectors don't
    seem to be optimal. I currently have a 1W LED flashlight which is pretty amazing, but I don't
    believe it has enough light for cycling at any significant speed. I have one of these Planet Bike
    units on order, and plan to modify it using the 3W Luxeon Star if possible ($13 from
    www.elekrolumens.com). If it works out, I'll post my findings.


    The car at this link autoextremist.comMEFour
    TwelveShow.jpg This Chrysler protype car at the current Detroit auto show uses LED for headlight and
    tail lights. I have a 30 LED unit that I adapted for my bicycle that is bright enough for me as a
    low beam, right side facing in the picture below. Also in the picture is a 10 watt Halgon used for a
    high beam. billcotton.com1156%20light%20complete%202.jpg Of course I have a machine shop
    at home. The technogy is moving faster that manufacturer can respond. LED are here to stay for
    lighting. Already being used in traffic lights and auto taillight. So wait a while and they will be
    here. I have gotten 6 hours from a battery pack before my voltage indicator shows less than 12
    volts. the the LED are still on but dimmer.

  14. Ron Hardin <[email hidden]> wrote in message news:<[email hidden]>...

    Quoted message said:
    David L. Johnson said:


    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the
    moment I use a 15W Nightrider, but am interested in something that would last longer and still
    have enough light.

    Are there LED lights that really do the job? How many watts would it take?

    That would be nearly enough light if it's not generating heat; but the LED reputation for
    lasting a long time comes from its not drawing much current, which until now has meant not much
    light either.

    Not so. The LED reputation for lasting a long time comes from LEDs being solid state electronic
    devices, not high-temperature bits of super-thin tungsten wire.

    White-hot tungsten filaments gradually lose their thickness until they break - that is, burn out.
    LEDs are entirely different. They last very close to forever.

    Quoted message said:

    So waiting for LEDs to throw out more light so as to get a longer runtime is doomed to failure
    from the start, except for some constant factor from LED efficiency, say two, from not generating
    heat as well.

    Regarding efficiency: The last time I checked, the efficiency (i.e. lumens per watt) of white LEDs
    was no better than that of a decent halogen bulb, assuming the bulb was at the optimum voltage or
    current. However, LED technology seems to be advancing _very_ rapidly, so I suppose I should check
    around again.

    But a subtle benefit to LEDs is that their efficiency is much less effected by variations in voltage
    (or current, if you prefer). If you decrease an incandescent bulb's voltage by a small amount (say
    10%) you get _way_ less lumens per watt. You get much longer life, but that's not usually what we
    cyclists need.

    OTOH, if you decrease an LED's voltage (say, by a battery beginning to die) the LED still does a
    good job of pumping out light. For that reason, it gets more light out of a given battery.

    - Frank Krygowski

  15. I found your post here very interesting, Rosco, thanks.

    Here is the corrected link for Elektrolumens www.elektrolumens.com as I could not get the link in
    your message to open.

    --
    Lewis.

    .........................

    *******************************

    "rosco" <reverse-the-following"ocsor_g"@hotmail.com> wrote in message
    "]news:[email hidden]...

    Quoted message said:


    "David L. Johnson" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or


    so).

    Quoted message said:
    Quoted message said:

    Now, 1 watt does not seem like much. At the moment I use a 15W Nightrider, but am interested in
    something that would last longer and still have enough light.

    Are there LED lights that really do the job? How many watts would it


    take?

    Quoted message said:


    --

    David L. Johnson

    I may have been that guy. The light is the Planet Bike Super Spot
    (planetbike.comfeature.html) at ~$35. Performance was selling it for ~$30 as an intro
    price. A call to Planet Bike confirmed that they use the Lumileds Luxeon Star 1W part. They say
    price is the only thing keeping them from using the higher output Luxeon Star parts. One of the
    frustrating things about the rating of bike lights is that everyone seems


    to

    Quoted message said:

    quote watts as the yardstick. Watts tells you how much power the unit consumes, it doesn't tell
    you how much light (in lumens) is output. I believe that LED lights have higher efficiency as they
    produce more lumens/watt than your standard halogen type bulb so using watts isn't a


    good

    Quoted message said:

    unit of comparison. For the future, Lumileds propaganda talks about


    output

    Quoted message said:

    going from about 20 lumens/watt to around 50 lumens/watt in a couple of years so the future of LED
    lighting for bicycles might be promising. The other challenge in LED light design seems to be the
    optics; standard


    halogen

    Quoted message said:

    reflectors don't seem to be optimal. I currently have a 1W LED flashlight which is pretty amazing,
    but I don't believe it has enough light for


    cycling

    Quoted message said:

    at any significant speed. I have one of these Planet Bike units on order, and plan to modify it
    using the 3W Luxeon Star if possible ($13 from www.elekrolumens.com). If it works out, I'll post
    my findings.

  16. Chalo said:

    There are other advantages to LED illumination, though. Light color and beam quality are usually
    superior to incandescents

    Is that "superior" as in "looks a bit like a Mercedes with xenon headlamps"? ;-)

  17. "Lewis Campbell" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I found your post here very interesting, Rosco, thanks.

    Here is the corrected link for Elektrolumens www.elektrolumens.com as I could not get the link in
    your message to open.

    --
    Lewis.

    Thank you for the correction. Sorry about the typing error.

  18. Today's LED headlights will not compare to your NR. They have three major
    hurdles to overcome:

    1) Efficiency (lumens/watt)
    2) Output above a few watts
    3) Reliability (at said output levels)

    If you're looking for something to last longer buy or, better yet, build yourself a larger battery.
    It will be some time, if ever, that LED technology improves to the point of being a serious
    alternative to the your high power (>10W) light.

    "David L. Johnson" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the moment
    I use a 15W Nightrider, but am interested in something that would last longer and still have
    enough light.

    Are there LED lights that really do the job? How many watts would it


    take?

    Quoted message said:


    --

    David L. Johnson

    __o | This is my religion. There is no need for temples; no need for _`\(,_ | complicated
    philosophy. Our own brain, our own heart is our (_)/ (_) | temple. The philosophy is kindness.
    --The Dalai Lama

  19. "rosco" <reverse-the-following"ocsor_g"@hotmail.com> wrote in message
    "]news:[email hidden]...

    Quoted message said:


    "David L. Johnson" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or


    so).

    Quoted message said:
    Quoted message said:

    Now, 1 watt does not seem like much. At the moment I use a 15W Nightrider, but am interested in
    something that would last longer and still have enough light.

    Are there LED lights that really do the job? How many watts would it


    take?

    Quoted message said:


    --

    David L. Johnson

    I may have been that guy. The light is the Planet Bike Super Spot
    (planetbike.comfeature.html) at ~$35. Performance was selling it for ~$30 as an intro
    price. A call to Planet Bike confirmed that they use the Lumileds Luxeon Star 1W part. They say
    price is the only thing keeping them from using the higher output Luxeon Star parts. One of the
    frustrating things about the rating of bike lights is that everyone seems


    to

    Quoted message said:

    quote watts as the yardstick. Watts tells you how much power the unit consumes, it doesn't tell
    you how much light (in lumens) is output. I believe that LED lights have higher efficiency as they
    produce more lumens/watt than your standard halogen type bulb so using watts isn't a


    good

    Quoted message said:

    unit of comparison. For the future, Lumileds propaganda talks about


    output

    Quoted message said:

    going from about 20 lumens/watt to around 50 lumens/watt in a couple of years so the future of LED
    lighting for bicycles might be promising. The other challenge in LED light design seems to be the
    optics; standard


    halogen

    Quoted message said:

    reflectors don't seem to be optimal. I currently have a 1W LED flashlight which is pretty amazing,
    but I don't believe it has enough light for


    cycling

    Quoted message said:

    at any significant speed. I have one of these Planet Bike units on order, and plan to modify it
    using the 3W Luxeon Star if possible ($13 from www.elekrolumens.com). If it works out, I'll post
    my findings.

    Halogens are about 70 lumens/Watt. As the junction temperature of the diode increases things get
    worse in a hurry. Reliability at high output/junction temperatures is also going to be a big issue.

  20. David L. Johnson" <[email hidden]> wrote in message news:<[email hidden]>...

    Quoted message said:

    I've been curious, from following a couple of sort-of related threads. One guy pointed to a site
    that had a 1W single LED light (for $35 or so). Now, 1 watt does not seem like much. At the moment
    I use a 15W Nightrider, but am interested in something that would last longer and still have
    enough light.

    Are there LED lights that really do the job? How many watts would it take?

    I have a Cateye EL-300 (5-LED headlight). Does it do the job? That depends what the job is.

    It is a good backup to my halogen lights with enough light to see by on familiar routes (or if
    travelling cautiously). Runs for ages on 4AA's, so you don't have to worry about running out of
    light after an hour or two.

    Also fine away from other lights in open country (once your eyes become dark-adjusted you really
    don't need that much light to see by, a full moon gives quite enough - bright lights just throw what
    is beyond their range into total blackness by contrast - of course, light polluted areas or dark
    woods are a different matter).

    I use it in conjunction with a strobe flasher as it is focussed quite tightly and I'm not convinced
    that it gets me seen very well.

    A final point. Power is relevant to run-time, but not directly to brightness (particularly between
    different technologies such as filaments and LEDs). Light output can be equally misleading as how
    tightly the beam is focussed will have a dramatic impact on what you can see. You really have to try
    a light in your particular sutuation to see if a light is suitable, there isn't a "one size fits
    all" solution in the compromise between run-time, light output and beam dimension.

    Andrew Webster

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