rear lights

[Dmitri Colebatc]

motivated by the thread of hi beams, I have a query about rear lights. I'm continually amazed that you can get lights that look the same as a motorbike from in front in terms of brightness, but when it comes to rear lights, we all ride around with flashing LEDs. I for one (justified or not) am much more concerned about a car behind me hitting me, rather than one I can see. If I can see a car, chances are I can avoid the driver's stupidity/ignorance, but if I dont see it coming, then what chance
do I have. For this reason, I've always wanted to (never have, yet) get a big headlight, with a red tint as a rear light.

anyone else got any thoughts on this?

cheers dim

 

[Mike]

Dmitri Colebatch wrote:
> but when it comes to rear lights, we all ride around with flashing LEDs.

Thats because a _good_ flashing LED lamp is incredibly visible. Add reflectors on
heels, wheel rims, etc for bonus safety. And LEDs are far more efficient for
coloured light than incandescents.

 

[Ray Peace]

Greetings, The primary constraint on bike rear lights is
available power. I still have an ancient dynamo system, and
they allocate a mere .5 watt to the tail light and 2.4 watts
to the head-light, which is why I have an LED light as a back-
up at the rear. If you want a more powerful tail-light, you
will pay for it in either needing a 6 watt system, or more
(and heavier) batteries, as well as moolah. The advent of
LED lights is some improvement over the absolutely pathetic
output of many previous tail-lights, but we are still not as
visible as cars because we don't have a 12 volt, heavy duty
battery system. As I don't do a lot of night riding at the
present it doesn't bother me unduly, but I'm certainly aware
of the problem, and also of some of the work that has been
done on it. Regards, Ray.

Dmitri Colebatch wrote:

>motivated by the thread of hi beams, I have a query about
>rear lights. I'm continually amazed that you can get lights
>that look the same as a motorbike from in front in terms of
>brightness, but when it comes to rear lights, we all ride
>around with flashing LEDs. I for one (justified or not) am
>much more concerned about a car behind me hitting me,
>rather than one I can see. If I can see a car, chances are
>I can avoid the driver's stupidity/ignorance, but if I dont
>see it coming, then what chance do I have. For this reason,
>I've always wanted to (never have, yet) get a big
>headlight, with a red tint as a rear light.
>
>anyone else got any thoughts on this?
>
>cheers dim

 

[Laurence Dodd]

In reply to your post about bright rear bike lights (as a
recommendation).

I bought a Daylight Bright Bicycle light for $123 which
includes postage and its works very well. The following is
some information from me about my experience with the light.

The light is fairly visible in bright daylight. It is very
visible under street lights at night. I even once had a
passing passenger call out: "Your bike light's on fire!".
That is what it must have looked like to him.

The light unit is made and supplied by one man as far
as I know.

I don't have any pictures (no digital camera here, but you
can see it in a review in Australian Cyclist magazine from
2003 (see their website)). It weighs about 100g. Read on for
the dimensions.

The backing plate on mine extends up along the longer
dimension, so it is wider than the seat. When mounted on the
seatpost it touches the back of my legs, which is why I
mounted mine under the seat via the seat rails. The light is
not aethestically beautiful, but it is functional.

I recommend this light for cyclists, but under the above
disclaimers that it is not perfectly designed. I am happy to
have spent the money, but anyone else does so at their own
risk of dissatisfaction. Perhaps get the manufacturer to
send you some pictures.

Kind Regards,

Laurence Dodd.

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

The following is information from the manufacturer.

Thank you for your enquiry re the world's brightest bicycle
tail light!

For seat post mounting, the mounting plate comes with a U-
bolt to suit a 25mm seat post and is $8 extra. Please advise
your seat post diameter if not 25mm.

The long dimension would normally be horizontal but people
have mounted these lights vertically with a specially
designed mounting plate.

The light is designed to be charged on-bike. You would need
a specially designed mounting to allow easy removal if you
wished to remove the light for charging. For most cyclists
recharging would only be required once a week. One option
for a commuter cyclist might be to charge the light at work
during the day.

I make the lights myself here in Sydney and ride to work in
the city using one.

Postage is $8. The lights are not sold through shops.

Regards, Bill Holliday, WMH Electronics P/L

...........................................................-
..............

Daylight Bright Bicycle Tail Light

Cyclists can be put in the direct path of overtaking motor
traffic by

chicanes, traffic islands, speed humps and the S-lane's
disappearing

left hand lane.

In such situations cyclists are effectively denied on-road
access unless

they are able to enter and occupy a lane when necessary.
To do this,

cyclists need to be very visible from behind, both day
and night.

The Daylight Bright tail light focuses the attention of
approaching

traffic on the presence of the cyclist and identifies the
cyclist as such.

Daylight Saving causes many commuter cyclists to travel
at sunset. A

bright tail light makes cyclists more visible against the
setting sun.

The Daylight Bright bicycle tail light stands out from a sea
of

headlights, trafficators and other tail lights because of
its brightness

and characteristic flash rate.

FEATURES:

Mega-bright:

Has by far the highest flash intensity of any bicycle tail
light. Twenty

four high-power LEDS provide more than 600,000 mcd - as
bright as a

traffic light. Easily visible at night at 1 km (on-axis).

Internal Rechargeable Batteries

Five internal 650mAh AAA rechargeable NiMH batteries
operate the light

for 6 hours in full flash mode or 12 hours in alternating
flash mode.

Built-in recharging Circuit:

Any 9 to 24 volt plugpack will power the internal constant-
current

recharging circuit to recharge the batteries overnight.
A suitable

plugpack is available separately. The light is designed to
be recharged

in situ - it is not necessary to remove it from the bike.

A green recharging indicator LED shows when recharging is
taking place. Water resistant design: The light uses a
waterproof case with neoprene sealing gasket between the
transparent lid and the tough ABS body. The batteries are
soldered in place - no contacts to corrode and prevent the
light from operating.

Mounting:

The light should be firmly mounted on the bicycle to
point directly

backwards. The case dimensions are 115x65x40 mm with two
4mm mounting

holes located outside the sealed volume.

Mounting requirements vary widely depending where the
light is to be

attached. A dual-purpose mounting kit, for seat post
or backstay

mounting, is available from the manufacturer.

MANUFACTURED BY:

WMH Electronics Pty Ltd

ABN 19 101 848 435

Ph/Fax: 9569-4956 (H)

Email: wmh@ ieee.org

 

[Drs]

Mike <[email protected]> wrote in message
[email protected]
> Dmitri Colebatch wrote:
>> but when it comes to rear lights, we all ride around with
>> flashing LEDs.
>
> Thats because a _good_ flashing LED lamp is incredibly
> visible.

As long as it can be seen. I bought a Topeak "wedge" saddle
bag on Saturday. When I fitted it I found I couldn't have it
and my rear light mounted at the same time. So, in order to
have a rear light and the saddle bag I either have to buy a
new rear light which mounts on the saddle bag itself:

http://www.topeak.com/global/redlite.php

or I have to buy a "seat pack fixer":

http://www.topeak.com/global/fixers.php

Grrrrr.

--

A: Top-posters.
B: What is the most annoying thing on Usenet?

 

[Mike]

DRS wrote:

> As long as it can be seen. I bought a Topeak "wedge"
> saddle bag on Saturday. When I fitted it I found I
> couldn't have it and my rear light mounted at the same
> time. So, in order to have a rear light and the saddle bag
> I either have to buy a new rear light which mounts on the
> saddle bag

You have a mounting strap onto the back of the saddle bag? I
thought most LEDs had a clip for that. Just be sure it stays
at the right angle. Otherwise, you could just screw it on to
the saddle bag, with a backplate inside.

I suppose getting a rear rack is out of the question?

>
> http://www.topeak.com/global/redlite.php

 

[Drs]

Mike <[email protected]> wrote in message
[email protected]
> DRS wrote:
>
>> As long as it can be seen. I bought a Topeak "wedge"
>> saddle bag on Saturday. When I fitted it I found I
>> couldn't have it and my rear light mounted at the same
>> time. So, in order to have a rear light and the saddle
>> bag I either have to buy a new rear light which mounts on
>> the saddle bag
>
> You have a mounting strap onto the back of the saddle bag?

Yes. Didn't you look at the links?

> I thought most LEDs had a clip for that. Just be sure it
> stays at the right angle. Otherwise, you could just screw
> it on to the saddle bag, with a backplate inside.

I looked at my current one but I don't see how it
would clip on.

> I suppose getting a rear rack is out of the question?

Just what I need, more weight on the bike.

--

"I'm proud that I live in a country where witnessing two
hours of bloody, barbarous torture in gloating detail is
considered indicia of religious piety, whereas a mere second
gazing upon a woman's breast is cause for outraged
apoplexy." Betty Bowers,
http://www.bettybowers.com/melgibsonpassion.html

 

[Joel Mayes]

In article <[email protected]>, Dmitri Colebatch wrote:
> motivated by the thread of hi beams, I have a query about
> rear lights. I'm continually amazed that you can get
> lights that look the same as a motorbike from in front in
> terms of brightness, but when it comes to rear lights, we
> all ride around with flashing LEDs. I for one (justified
> or not) am much more concerned about a car behind me
> hitting me, rather than one I can see. If I can see a car,
> chances are I can avoid the driver's stupidity/ignorance,
> but if I dont see it coming, then what chance do I have.
> For this reason, I've always wanted to (never have, yet)
> get a big headlight, with a red tint as a rear light.
>
> anyone else got any thoughts on this?
>
> cheers dim

Red LED read lights are extremly visable at night, if there
mounted on the seat post or rear rake of a bike, wearing
them on a helmet is not as effective.

You can post these flashing things from several blocks away,
its all I have on the rear of my bike and I'm quite
confident in it.

--
| Joel Mayes | /~\ ASCII Ribbon campaign Accordionist | \_/
| stop HTML mail and news Musician | / \ Music Teacher |

 

[Mike]

Joel Mayes wrote:
> wearing them on a helmet is not as effective.

Why is that? I have one of those swivel-mounted ones, so it
always shines horizontally. Makes a nice eye-level backup
for the rack-mounted lights. Anyone sell them in Oz?

http://www.mec.ca/Products/product_detail.jsp?PRODUCT%3C%3E-
prd_id=15909

 

[Joel Mayes]

In article <[email protected]>, Mike wrote:
> Joel Mayes wrote:
>> wearing them on a helmet is not as effective.
>
> Why is that? I have one of those swivel-mounted ones,
> so it always shines horizontally. Makes a nice eye-
> level backup for the rack-mounted lights. Anyone sell
> them in Oz?
>
> http://www.mec.ca/Products/product_detail.jsp?PRODUCT%3C%-
> 3Eprd_id=15909

I've seen many riders with collars or bags which partially
obscure the light, probably not a valid issue if you are
careful about how you dress, and how you mount the light.

--
| Joel Mayes | /~\ ASCII Ribbon campaign Accordionist | \_/
| stop HTML mail and news Musician | / \ Music Teacher |

 

[John Retchford]

Originally posted by Mike
Joel Mayes wrote:
> wearing them on a helmet is not as effective.

Why is that? I have one of those swivel-mounted ones, so it
always shines horizontally. Makes a nice eye-level backup
for the rack-mounted lights. Anyone sell them in Oz?

http://www.mec.ca/Products/product_detail.jsp?PRODUCT%3C%3E-
prd_id=15909

Many of the LEDs used in bicycle tail lights are pretty directional, some particularly so, making it important to mount the thing in the right direction. I think this is most reliably accomplished by mounting it on the bicycle. Your swivelling light attached to your helmet will only be correctly positioned if you always hold your head in a particular way, which does not seem practical to me.

This morning I came up behind another rider on what appeared to be a totally unlit bicycle. Only as I passed her did I see a flashing light attached to the retention strap at the rear of her helmet. She was sitting upright on a fairly upright bicycle and the light was shining down and invisible from behind. Presumable it would have been visible had she ridden in a more normal posture, but most riders move around - riding on the tops, the hoods and the drops.

John Retchford

 

[Mike]

John Retchford wrote:
> Your swivelling light attached to your helmet will only be
> correctly positioned if you always hold your head in a
> particular way, which does not seem practical to me.

By "swivelling", I mean it is self levelling, by gravity, so
the head tilt doesnt matter.

> the light was shining down and invisible from behind.

A common problem.