One of the things I wanted to do to my bikes this winter was to retrofit LED's in place of the wimpy bulb that is there. I wanted to get that hip eyebrow look without doing anything that could not be reversed if it didn't work out.
Because of the diffraction of the lens I wanted the LED's as close to it as possible. I decided to try putting them on some foam put on top of the original reflector. That worked pretty well, but I didn't like the way the strip showed through the lens, so I put a mask over them. Whole job took about an hour and a half once the headlight was out of the fairing.
Total materials was a couple waterproof strips of the brightest white LED's I could find on eBay(50cm 30LED waterproof smd5050 strips), some 1/2" and 1/4" gray foam, wire and connectors, shrink tube, black paint, and 3M Super 77 spray contact adhesive.
I cut two strips of 1/2" foam wide enough to be a friction fit in the reflector. I glued them together to make a piece 1" thick. I stuck them into the reflector after cutting a pocket in the back to take the old bulb.
Next I cut a piece of 1/4" foam a bit wider than the pieces I stuck into the reflector. I laid out the spacing for a number of 3/8" holes to let the LED's shine through. I painted it black with some spray paint and them put Super 77 on the back to stick the mask to the LED's.
While the paint was drying I peeled the backing off the LED's and stuck them to the foam. I drilled a hole in the housing to let the wire out, and soldered the the leads and put the connectors on. A cable tie for a strain relief and some shrink tubing finished the wiring.
With the wiring complete, I put the mask over the LED's and put the lens back on and powered things up. The lights had shifted slightly so I took the lens back off, adjusted them and put it back on. They are BRIGHT! The pictures don't come near showing how good they look.
Assuming you have some scraps of foam and wire available you should be able to do them pretty cheap. I did two bikes for under $10 total.
