Have they seen the light?

[Jonathan Larmou]

Geraint Jones <[email protected]> enlightened us with:
> [LEDs] flashing at a higher frequency should ease the problem of making it difficult to judge
> distances - something which is severly limited when the flashing rate is significant at the speeds
> which eyes jump about.

You wonder why manufacturers don't make lights with a mode that has a single steady LED with the
rest flashing.

Jifl
--
--[ "You can complain because roses have thorns, or you ]-- --[ can rejoice because thorns have
roses." -Lincoln ]-- Opinions==mine

 

[Geraint Jones]

"Pete Biggs" <[email protected]> wrote: ( However, I sometimes switch to steady mode
on darker narrow lanes where I ) do think a flashing light could be too dazzling to drivers as just
about ( the only thing they may see is the light (and perhaps reflectors).

Have you ever cycled any distance behind another cyclist with a flashing red light? I used to have a
commute which (usually in winter) ended with a long uphill in traffic in the dark, and being a
notoriously urgent uphiller trapped behind a slower bike with a hypnotically flashing rear light
used to drive me ever so mildly bonkers. I think I can still see the flashing light years later.

 

[Pete Biggs]

chris French wrote:
> I certainly don't like flashing LEDS and no other light showing. Not because I think it is
> distracting, but I think that it can be confusing esp. in a busy road environment. Mostly I think
> the problem is that although you may spot the light the flashing intermittent nature of the light
> makes it hard to place and to be sure of distance.

That's not altogether a bad thing if it makes motorists slow down and give more room - although this
is not what I'm trying to do exactly with mine. I use a flashing light simply to get noticed, as
well as saving batteries.

I don't want to use a large heavy rear light (or more than one rear light) so use a small LED job. I
tend to leave it on flashing mode because I'm sure it's not noticeable enough on steady in busy lit
urban environments - where there's so many other things around to distract the driver's attention.
The cyclist is just one of many objects in the wide field of view (and may be towards the edge of
the driver's vision). A small flashing light must better than a steady small LED light which may
never get noticed, or nothing, on these kind of roads.

However, I sometimes switch to steady mode on darker narrow lanes where I do think a flashing light
could be too dazzling to drivers as just about the only thing they may see is the light (and perhaps
reflectors). This is where they need all the help they can get to get a "fix" on the cyclist's
position, and, hopefully, even a relatively low powered steady light should contrast well against
the blackness here to get the driver's attention in the first place.

But driving at safe speeds on better lit and slower roads, motorists should not need to rely on the
cyclist's light to judge where they are as they follow or pass. And common flashing rear LEDS are
not bright or dazzling enough to be dangerous on typical urban roads, imo.

Regarding LED's on clothing: Doesn't seem to work well with the cyclists I see. The lights usually
end up pointing in stupid directions. The point about the legaility might be part of the answer why
they don't bother mounting the flashing lights to bike.

~PB

 

[David Gillbe]

You are all missing a key point, the fact that (as quoted on a LED light I just bought recently) "Do
not use in flashing mode when attached to your cycle as this is in contravention of the road vehicle
and lighting regulations"

Thus, since we like to tell other motorists about how they should follow the highway code, perhaps
we should as well and leave our LED lights on constant mode Dave

 

[Just Zis Guy]

On 20 Jan 2003 16:01:40 -0000, [email protected] (Geraint Jones) wrote:

>trapped behind a slower bike with a hypnotically flashing rear light used to drive me ever so
>mildly bonkers. I think I can still see the flashing light years later.

Maybe I should rig up an emergency stop on my new RealLITE

Guy
===
** WARNING ** This posting may contain traces of irony. http://www.chapmancentral.com (BT ADSL and
dynamic DNS permitting)
NOTE: BT Openworld have now blocked port 25 (without notice), so old mail addresses may no longer
work. Apologies.

 

[Peter Clinch]

Pete Biggs wrote:

> I don't want to use a large heavy rear light (or more than one rear light) so use a small LED job.

Especially with a seatpost mount, I don't really see that two wee LED units will exactly rank as
troublesome... One constant, one flashing.

> I tend to leave it on flashing mode because I'm sure it's not noticeable enough on steady in busy
> lit urban environments -

There are LED back lights and LED back lights. I use a Cat AU-100, and I'm happy about its
visibility on lit urban roads. The (rather expensive) B&M dynamo rear on the 'bent is a single LED,
but being well designed and executed it seems to stand out quite well. OTOH I've seen (more by
chance than anything else) plenty that really are pretty hopeless.

> However, I sometimes switch to steady mode on darker narrow lanes where I do think a flashing
> light could be too dazzling to drivers as just about the only thing they may see is the light (and
> perhaps reflectors).

I switch the AU-100 to flashing in lower light levels, something like a drab day or as the light is
starting to fail. When it's dark I keep it on constant. Friends approaching me from behind in cars
(on rural and urban roads) have commented that they saw my reflectors well before the main light
was clear. Good reflectors make a *lot* of difference, even just the triangles on a couple of
panniers (now got the back of the 'bent seat coated with enough Scotchlite to start a shop!) or
piping on a jacket.

> Regarding LED's on clothing: Doesn't seem to work well with the cyclists I see. The lights usually
> end up pointing in stupid directions. The point about the legaility might be part of the answer
> why they don't bother mounting the flashing lights to bike.

Agreed about the usefulness (limited, at best, and it often isn't "at best"), though I think just
not having an attachment bracket on the bike, but one on a pack or jacket, is usually more to do
with it than the legality issue.

Pete.
--
Peter Clinch University of Dundee Tel 44 1382 660111 ext. 33637 Medical Physics, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK net [email protected]
http://www.dundee.ac.uk/~pjclinch/

 

[Tony W]

"Pete Biggs" <pLime{remove_fruit}@biggs.tc> wrote in message
news:[email protected]...
>
> That's not altogether a bad thing if it makes motorists slow down and give more room - although
> this is not what I'm trying to do exactly with mine. I use a flashing light simply to get noticed,
> as well as saving batteries.
>
> I don't want to use a large heavy rear light (or more than one rear light) so use a small LED job.
> I tend to leave it on flashing mode because I'm sure it's not noticeable enough on steady in busy
> lit urban environments - where there's so many other things around to distract the driver's
> attention. The cyclist is just one of many objects in the wide field of view (and may be towards
> the edge of the driver's vision). A small flashing light must better than a steady small LED light
> which may never get noticed, or nothing, on these kind of roads.
>
> However, I sometimes switch to steady mode on darker narrow lanes where I do think a flashing
> light could be too dazzling to drivers as just about the only thing they may see is the light (and
> perhaps reflectors). This is where they need all the help they can get to get a "fix" on the
> cyclist's position, and, hopefully, even a relatively low powered steady light should contrast
> well against the blackness here to get the driver's attention in the first place.
>
> But driving at safe speeds on better lit and slower roads, motorists should not need to rely on
> the cyclist's light to judge where they are as they follow or pass. And common flashing rear LEDS
> are not bright or dazzling enough to be dangerous on typical urban roads, imo.
>
> Regarding LED's on clothing: Doesn't seem to work well with the cyclists I see. The lights usually
> end up pointing in stupid directions. The point about the legaility might be part of the answer
> why they don't bother mounting the flashing lights to bike.

The read LED's I use weigh less than 50g so weight is hardly a consideration. I think it is worth
having a couple -- if for no other reason their is some redundancy if one fails.

Your logic on which mode to use is pretty faultless -- though with 2 lights I have one steady and
one flashing.

LED lights are VERY directional (another reason to have more than one!!). This means it is generally
a waste of time,e fitting one to yourself -- and even a loop designed for the purpose on a seat
wedge or bag can sag fairly quickly. Solid mounting is best.

T

 

[Eddie Dubourg]

"Tony W" <[email protected]> wrote in message news:b0h637$otkp9
>
> The read LED's I use weigh less than 50g so weight is hardly a consideration. I think it is worth
> having a couple -- if for no other reason their is some redundancy if one fails.
>
> Your logic on which mode to use is pretty faultless -- though with 2
lights
> I have one steady and one flashing.
>
> LED lights are VERY directional (another reason to have more than one!!). This means it is
> generally a waste of time,e fitting one to yourself --
and
> even a loop designed for the purpose on a seat wedge or bag can sag fairly quickly. Solid mounting
> is best.

I find that with flashing rear lights, I sometimes have problems working out whether it's someone
close to me with a flashing light, or someone a distance away behind a hedge or similar.

I have one of the tiny Cateye triple LED rears ziplocked to my helmet which seems very stable (and a
couple, one of which is BSwhatever compliant, on my seatpost).

I think Harris Cyclery sell a self-levelling rear light for head mounting.

What will they think of next?

E

 

[James Annan]

Chris Malcolm wrote:

>
> What chance has Britain of ever creating a well-regulated market place to encourage scientific
> research and technological development when we make such a comprehensive mess of legislating
> bicycle lamps?

Perhaps they are merely trying to learn from the Japanese approach...

James

 

[Geraint Jones]

"David Gillbe" <[email protected]> wrote:
> You ...

Who? And on what evidence?

 

[Just Zis Guy]

On Tue, 21 Jan 2003 08:33:51 +0000, Colin Blackburn <[email protected]> wrote:

>Except you now have the issue or carrying a spare bulb! ;-)

No worries. I have three, plus a micro maglite for changing them, the whole lot fits in the micro
maglite's plastic box and tips the scales at about 60g.

Guy
===
** WARNING ** This posting may contain traces of irony. http://www.chapmancentral.com (BT ADSL and
dynamic DNS permitting)
NOTE: BT Openworld have now blocked port 25 (without notice), so old mail addresses may no longer
work. Apologies.