best red LEDs for home made bicycle lighting ??

[brugnospamsia]

Dear group

I've just made myself a 9 watt fluorescent front light for my bike from a
decapitated mains CFL and a camping light invertor. It replaces a 12 volt 21
watt "reversing light" (early days yet - it remains to be seen how it'll
cope with cold, damp and vibration).
It's designed to be seen by others rather than to see by. (I plan to add a
20 or 50 watt dichroic spot for doggy doodo and broken glass avoidance.)

http://uk.geocities.com/gentlegreengiant/cyclelight.JPG

While I remain unconvinced about LEDs for the front light, I now have a
notion to replace the effective but inefficient12/21 tail-light with LEDs,
(if only someone would make a 9 watt "D" CFL with red phosphor ! ) ....but
I'm overwhelmed by the vast range of superbright red LEDs on the market.

I wonder if anyone here has worked out the most cost-effective device
specification for this purpose - would a shed-load of lower intensity
devices be more effective than a few ultra-bright narrow angle ones for
instance?

Jeremy,

UK

 

[Michael]

Dear group

I've just made myself a 9 watt fluorescent front light for my bike from a
decapitated mains CFL and a camping light invertor. It replaces a 12 volt 21
watt "reversing light" (early days yet - it remains to be seen how it'll
cope with cold, damp and vibration).
It's designed to be seen by others rather than to see by. (I plan to add a
20 or 50 watt dichroic spot for doggy doodo and broken glass avoidance.)

http://uk.geocities.com/gentlegreengiant/cyclelight.JPG

While I remain unconvinced about LEDs for the front light, I now have a
notion to replace the effective but inefficient12/21 tail-light with LEDs,
(if only someone would make a 9 watt "D" CFL with red phosphor ! ) ....but
I'm overwhelmed by the vast range of superbright red LEDs on the market.

I wonder if anyone here has worked out the most cost-effective device
specification for this purpose - would a shed-load of lower intensity
devices be more effective than a few ultra-bright narrow angle ones for
instance?

Jeremy,

UK

The ultra-brights, because of the geometry of their packaging, are
"point sources" and also very directional. They're much more noticable
when used in groups, spaced apart from each other by a bit. On my bike
I use 6 ultra-brights within a 2.25" diameter housing. Might be a bit
of overkill but the idea is to be seen.

I'm curious to know if the CFL is rugged enough to last. I considered
building a CFL front light (again, to *be* seen; not to see) but nixed
the idea because of pretty strong shock and vibe (I ride 1.25", 100 PSI
tires on poor pavement).

Michael

 

[brugnospamsia]

The ultra-brights, because of the geometry of their packaging, are
"point sources" and also very directional. They're much more noticable
when used in groups, spaced apart from each other by a bit. On my bike
I use 6 ultra-brights within a 2.25" diameter housing. Might be a bit
of overkill but the idea is to be seen.

I'm curious to know if the CFL is rugged enough to last. I considered
building a CFL front light (again, to *be* seen; not to see) but nixed
the idea because of pretty strong shock and vibe (I ride 1.25", 100 PSI
tires on poor pavement).

You're clearly hardier and / or younger than me.
I use a mountain bike with front suspension and gel saddle for my twice 4
mile daily commutes on fairly good roads . (my weight is stubbornly the
wrong side of 200lbs and I break wheels) I had to add a suspension seatpost
when I ditched the knobblies.

At the moment the lamp is only loosely attached by zip cable ties and
bouncing on the brake cables as was the previous one. .
The interesting thing will be windchill, but we no longer have proper
winters in the UK and even a CFL should generate enough heat to compensate.
I'll probably put in some silica gel sachets for the damp.

I'll try to remember to update my website with the success .... or otherwise
;-).

Jeremy

 

[Spehro Pefhany]

I wonder if anyone here has worked out the most cost-effective device
specification for this purpose - would a shed-load of lower intensity
devices be more effective than a few ultra-bright narrow angle ones for
instance?

For a rear light, I don't think there's any question that it should
blink at a visible rate and with high intensity. Unless that's illegal
where you are.


Best regards,
Spehro Pefhany

 

[brugnospamsia]

For a rear light, I don't think there's any question that it should
blink at a visible rate and with high intensity. Unless that's illegal
where you are.

It's a constant source of amazement to me how many fellow cyclists take to
the roads in the UK "undertaking" cars with no lights at all. One would
think they'd never sat behind the windscreen of a car at night .... Having
driven a van with no side windows I know better ....

In 17 years of cycling on Bristol's roads lit up like a Christmas tree I
appear not to have convinced a solitary cyclist to do the same.

I believe flashing lights are still strictly speaking illegal here unless
attached to the rider.
I am amazed that useless 1.5 watt lamps are deemed OK and "kite marked".

My lighting has evolved over time. I gradually increased the front lamp
from 5 to 10, then 21 watts - at which point cars stopped pulling out from
side roads in front of me quite so often.

I have to say I personally find flashing LEDs irritating which is why I
currently have a single 21watt car lamp on the back - probably more light
than the four 5 watt tail lights my car has. "Touch wood" I get noticed on
the road

Jeremy

 

[Rich Grise]

My lighting has evolved over time. I gradually increased the front lamp
from 5 to 10, then 21 watts - at which point cars stopped pulling out from
side roads in front of me quite so often.

I have to say I personally find flashing LEDs irritating which is why I
currently have a single 21watt car lamp on the back - probably more light
than the four 5 watt tail lights my car has. "Touch wood" I get noticed on
the road

You might not want it blindingly bright - you don't want to create a
different hazard!

Good Luck!
Rich

 

[Dave Garnett]

For a rear light, I don't think there's any question that it should
blink at a visible rate and with high intensity. Unless that's illegal
where you are.

I'm not convinced about flashing, because of the 'moth' effect - driver
fixates on it and steers towards it ! There is a lot to be said for just
making it bright. I used to use a 20w halogen bulb in my rear light - so
bright that drivers didn't know what it was and approached carefully (well,
most of them).

Dave

 

[brugnospamsia]

I'm not convinced about flashing, because of the 'moth' effect - driver
fixates on it and steers towards it ! There is a lot to be said for just
making it bright. I used to use a 20w halogen bulb in my rear light - so
bright that drivers didn't know what it was and approached carefully (well,
most of them).

I reckon mine are similarly effective.

One evening on the way home I cycled the wrong way up the one-way street in
which I live (as has been my wont for 17 years) and a paramedic ambulance
followed me ... the driver got out and followed me right to my door ..

Fortunately the casualty was next door plus 1.

Jeremy

 

[Ken Smith]

brugnospamsia wrote: [...]
I'm curious to know if the CFL is rugged enough to last. I considered
building a CFL front light (again, to *be* seen; not to see) but nixed
the idea because of pretty strong shock and vibe (I ride 1.25", 100 PSI
tires on poor pavement).

If the temperatures are moderate, you should look at the products from
E.A.R. I've used the gromets from them to mount a PCB in something that
gets dropped and dragged over the ground on a daily basis. The PCB has so
far shown a failure rate of nil. The materal is mechanically very lossy.
It means that the mechanical resonances Qs are very low.

 

[Michael]

You're clearly hardier and / or younger than me.

Probably neither. I'm closer to 60 than 50 and passed 200 lb. years
ago. The 10-speed has a conventional saddle and no suspension, of
course. So, in rough going I keep my weight mostly on the BB, with some
on the drops. In really rough going I slow down, avoid trenches and
sinkholes and stay prepared to STOP.

I use a mountain bike with front suspension and gel saddle for my twice 4
mile daily commutes on fairly good roads . (my weight is stubbornly the
wrong side of 200lbs and I break wheels) I had to add a suspension seatpost
when I ditched the knobblies.

Avoid pot holes. Don't jump curbs. Your wheels will thank you. We
abused our fix-wheels when we were kids, but those bikes were very tough
and so were we. We and today's bikes are not up to taking on potholes
and curbs.

At the moment the lamp is only loosely attached by zip cable ties and
bouncing on the brake cables as was the previous one.

That should really decrease shock and vibe for you. You might get away
with CF.

(snip)

 

[Martin]

Hi,

I have meailed you (hopefully) via your website regarding your LED
dilemma.
Basically I am in the process of making and converting Motorcylcl tail
lamps to LED operation and as such I have numerous PCB created that
contain from 15 - nearly 100 RED leds. The smaller PCB's can easily
accomodate while LED's instead so one of these could be placed into
your smaller original front lamp.
Let me know if you are interested. I am not trying to creat a huge
commercial enterprise, just doing this as a hobby and to cover my
costs and make a couple of quid as well.

Regards,

Martin

Email me ledsforbikes at yahoo dot com

 

[Daniel Haude]

On Fri, 25 Feb 2005 13:30:27 +0000,

I have meailed you (hopefully) via your website regarding your LED
dilemma.

No you haven't. --D.