best red LEDs for home made bicycle lighting ??

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.)

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

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

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

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

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(well,

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

[...]

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.

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kensmith@rahul.net   forging knowledge

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.

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.

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

(snip)

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Michael

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

On Fri, 25 Feb 2005 13:30:27 +0000, Martin wrote in Msg.

No you haven't. --D.