Do you guys commute in the winter? - Page 4 - Cycling Mob: Road Cycling, Mountain Biking and More

11-08-2003, 03:47 PM

On 8 Nov 2003 14:35:23 -0800, [Only registered and activated users can see links. ] (Steven Scharf) wrote:

>This may be already available. The problem is that it will take a lot
>of LEDs to equal the same light output of a halogen. Already you see
>multi-LED flashlights. The problem then becomes that it is not possible
>to focus multiple LEDs like it is a single halogen bulb.

no a single one was as bright. and it put out the same amount of light so it
could be used as a headlight. I don't have access to my regular computer to look
it what they are called. but these fellows have been playing with them and are
getting good results.

11-09-2003, 09:32 AM

Steven Scharf wrote:

> I suggest that you check out the very excellent bicycle
> lighting web site (my site)...

:-) Could you give us a self-review of your singing, too?

--
Frank Krygowski

11-09-2003, 09:38 AM

Steven Scharf wrote:

> While
> driving I've had a hard time seeing bicycles with dual blinkies
> if they were the cheap ones made with the non-high brightness
> LEDs, and lacked a reflector behind the LEDs.

The line about "reflectors behind the LEDs" puzzles me. With the LEDs
I've examined (including high brightness ones), the light that comes out
the back is relatively dim and diffuse. I see no practical way to
reflect that light and focus it forward. The light that comes out the
front is already focused adequately (for a taillight, that is) and would
not benefit from a reflector.

What do these reflectors of yours look like??

--
Frank Krygowski

11-09-2003, 03:35 PM

In article <[Only registered and activated users can see links. ].edu>,
"frkrygowHALTSPAM" <"frkrygowHALTSPAM"@cc.ysu.edu> writes:
> Steven Scharf wrote:
>
> > While
>> driving I've had a hard time seeing bicycles with dual blinkies
>> if they were the cheap ones made with the non-high brightness
>> LEDs, and lacked a reflector behind the LEDs.
>
> The line about "reflectors behind the LEDs" puzzles me. With the LEDs
> I've examined (including high brightness ones), the light that comes out
> the back is relatively dim and diffuse. I see no practical way to
> reflect that light and focus it forward. The light that comes out the
> front is already focused adequately (for a taillight, that is) and would
> not benefit from a reflector.

I've noticed a significant improvement in blinkies with reflectors.

It's my guess that the reflector captures, not so much "rearward",
direct light from the LEDs themselves, but re-reflects light that's
been reflected backward from the back (the "inside") of the lens --
sort of re-cycles it, and gives it a second chance to go outward,
where it's supposed to go.

> What do these reflectors of yours look like??

A cross section like a wide, shallow \__/ with holes for the
individual LEDs to poke through. The top & bottom are upswept,
but the left & right aren't. They're usually removable
(sometimes they stick & hide inside the lens when you take it
off, and make you wonder where your reflector went), so it's
an easy experiment to compare brightness with the reflector
installed, against with the reflector removed. I just tried
it now. It's a good way to see spots for awhile :-)

Anyhow, I figure if a blinky comes with a reflector -- might as
well leave it in.

cheers,
Tom

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11-09-2003, 06:02 PM

"Slider2699" <[Only registered and activated users can see links. ]> wrote in message news:<GHEqb.114544$[Only registered and activated users can see links. ].c om>...
> I live in Florida, so winter weather isn't a problem, but it gets dark at 6
> PM or earlier during the winter. I work a 9 to 5 so it's dark when I get
> home. I have a 20 mile commute, and I'm wondering if anyone is brave enough
> to commute 20 miles in the pitch black. Am I being a wuss or am I being
> sensible by not riding in the dark? I have a dual beam Vistalite and a bunch
> of blinkies but I'm not sure that's enough.

Let's assume that your lighting and reflectorization is adequate. The
other question is how much you trust the drivers in your area at
night.

Earlier this year I commuted 26 miles round trip by bike most of the
time. I was working an 8:30 am to 4:30 pm shift. Sometimes I would
have to come in early, at 4:30 a.m., and I liked riding in the
pre-dawn dark. There were few drivers on the road, and I figured most
of the drunks were sleeping it off by then.

Now I work 4:30 p.m to 12:30 a.m. It's still possible to ride my
bike, but I'd rather not be riding back after midnight. Granted, the
traffic is not too heavy, but the way I see people still driving at
that hour, I don't trust in visibility to safeguard me. I could be
wrong of course. It may actually be more dangerous during the 4:30
p.m rush hour, but I have to go with what seems reasonable to me.

Besides, now that I'm on night shift, I can enjoy riding during the
daylight hours. Here in Southern New England we haven't had snow yet.
I'll ride with the temperature in the teens and twenties, Fahrenheit.
Once the snow starts piling up, though, it's time to break out the
stationary trainer. Our roads are already pretty narrow. When enough
snow gets pushed over to the side, they're too narrow to share safely
with cars, IMHO.

11-10-2003, 11:01 AM

[Only registered and activated users can see links. ] (Tom Keats) wrote in
news:h0jmob.pvg.ln@bud.garden.local:

>
> A cross section like a wide, shallow \__/ with holes for the
> individual LEDs to poke through.

I just line the inside back of the thing with alu foil.

11-10-2003, 03:40 PM

[Only registered and activated users can see links. ] (Steven Scharf) wrote:

> though a better option is one of the Lightman bicycle
> Xenon strobes, also designed for bicycles:

My newest toy is an amber Lightman xenon strobe. When I received it I
immediately turned it on and was stunned by its brightness.

I did a conspicuity test Friday night. I have two Vistalite "Super
Nebula" 5 LED lights mounted side by side on the back of my rear rack,
and I mounted the Lightman strobe between and a little above the two
LED lights so that all three lights form a triangle configuration. I
leaned my bike up in the sidewalk in front of my house then drove down
the street and back, turning various lights on and off and changing
the angle of my bike between tests.

From very close up (i.e. less than 6 feet away and outside of my
vehicle), the xenon is almost blindingly bright compared to the red
LEDs. As I moved further from the back of the bike, however, the
difference became much less apparent. I don't know if it's the inverse
cube law kicking in or what, but the LEDs seemed in my subjective
judgement to be just as attention getting as the strobe, especially
from several car lengths away.

I'm glad I have the xenon and it's staying on my bike and it certainly
has its advantages and uses (e.g. fog conditions, better side
viewing). Furthermore, my test is somewhat unfair in that I'm
comparing a single xenon bulb to ten LED bulbs, but I really don't
think it's time to count LEDs out for nighttime "be seen" lighting.

RFM

11-10-2003, 04:27 PM

10 Nov 2003 15:40:57 -0800,
<[Only registered and activated users can see links. ] >, [Only registered and activated users can see links. ]
(Fritz M) wrote:

>Furthermore, my test is somewhat unfair in that I'm
>comparing a single xenon bulb to ten LED bulbs, but I really don't
>think it's time to count LEDs out for nighttime "be seen" lighting.

Especially when factoring in relative battery life and the danger
posed by falling Sea King helicopters.
--
zk

11-10-2003, 09:57 PM

Fritz M wrote:

>I really don't
> think it's time to count LEDs out for nighttime "be seen" lighting.
>

I've done lots of night riding with friends, but never seen a person
using a strobe taillight. Seems to me it would be _most_ annoying to
have such a person directly in front of you! Would you have any night
vision at all?

--
Frank Krygowski

11-12-2003, 07:52 AM

"frkrygowHALTSPAM" <"frkrygowHALTSPAM"@cc.ysu.edu> wrote in message news:<[Only registered and activated users can see links. ].edu>...
> Steven Scharf wrote:
>
> > While
> > driving I've had a hard time seeing bicycles with dual blinkies
> > if they were the cheap ones made with the non-high brightness
> > LEDs, and lacked a reflector behind the LEDs.
>
> The line about "reflectors behind the LEDs" puzzles me. With the LEDs
> I've examined (including high brightness ones), the light that comes out
> the back is relatively dim and diffuse. I see no practical way to
> reflect that light and focus it forward. The light that comes out the
> front is already focused adequately (for a taillight, that is) and would
> not benefit from a reflector.
>
> What do these reflectors of yours look like??

The reflector behind the LEDs is not to reflect the light
from the LED, it's to serve as a regular reflector of car
headlights.

Often the regular bicycle reflector is blocked completely by
the rear rack or by luggage, and in any case the reflector
that comes with the bicycle is too small to be effective.