Tuesday, January 30, 2007


Last summer I recycled a Sylvania LED light puck and a vintage headlight for my cruiser by taken it apart and jamming it in there. It works great and battery life is truly not an issue. I didn't document it because I figured that the puck at $10 was too expensive and the job was just too complicated. That's apart from the fact that it was a real crappy job and by some miracle it is still working to this day.

Then I came across those white LED keychains for $1. Now that's very affordable and they work off of 2 small 3V batteries cells. Now I'm no electrical engineer and what I'm about to present may not be a good set up, proof of the matter is I almost set this thing on fire while building it! So if any of you have additionnal info regarding resistors and such, please feel free to illuminate our lantern and post a comment about it. The pun was totally intended. :)

So here's how I did it. First, take that keychain light apart and retain the white LED. everything else you can toss away. You can keep those 3V cells for another project.

Second, get yourself a 4 AAA battery holder to get the 6 volts required to run that LED, a small switch and some wires. Don't forget the 4 AAA batteries. Wire it all up and make sure it works.

Third, take the bulbs and side connector of the headlight out. The switch screws right into the empty hole left by the connector on the headlight, no need to drill. Lose whatever wiring is left in there. Keep the brass clamps to hold your battery pack in place later.

Fourth, you'll need to plug the upper bulb hole with something shiny like chromed tape so you don't lose any reflective surface. Make a plug out of cardboard or anything else that will press fit the LED in it and the plug into the main bulb hole. If you need to use glue here, do not use superglue, it will fog up your lens and LED for ever. Use white glue, it has a strong bond when dry and it becomes clear when dry. Test everything again, close it up and install on your bike.

Those batteries should last a very long time. Now all you need is an LED red flashing light in the back and you can go night cruising without worrying about losing power to those vital lights. Remember, your main obejective is to be seen. Those white LED's do not go unnoticed, trust me.

Till next time, ride safe and Godspeed.



Anonymous said...

check http://www.kpsec.freeuk.com/components/led.htm#calculate and you will easily be able to calculate what kind of resistance you need. a 100 ohm would do the job in your case. don't run it without the resistance, because it will destroy the LED pretty quick.

Anonymous said...

Gary, nice tutorial. I just completed my taillights for the RRBBO kinda of using the same technique. Purchased a preassemble battery pack with switch and LED from Radio shack. I then cutoff the led and spliced on 2 more into vintage taillights.

Of course I just look at the link from the above comment and it said "Don't do this" Oh well, live and learn as long as nobody dies.

Gerry Lauzon said...

Thank you very much for this crucial information. Somehow I just knew that someone would lead me to the correct path. Just didn't figure it would be this quick! Cman, as long as we "live" and learn I guess we'll be ok. ;)


Anonymous said...

Here are some more bike light ideas

Anonymous said...


I can just imagine what you could do with a blender motor........

Unknown said...


this is exactly what I planned to do on my Dutch bike.
I'll send you a link when it will be done because I also plan to do it for the rear light.

Gerry Lauzon said...

Hold on to your hats everybody, I've found an even cheaper and easier way of doing this. New post to be added over the weekend after I take some pictures. Total cost of the operation is $1.


Bicycle Light said...

These lights are really good. they provide the rider with a clear visibility during the dark conditions. Such lights are good because they are a forms of reflectors and or a reusable source of light. i like your blog.

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