A few weeks ago I noticed a thread regarding led upgrades for bolt tail lights. I became interested in led technology and did a little research. During this research, I found that there plugin led replacements for some of the older type incandescent bulbs. However,it appeared that these replacement leds only matched the lumens output of the original incandescent bulbs. Then I discovered that there are plugin replacement incandescent bulbs for my 1157 type which offer significant increase in brightness. I bought a couple of the 2357 bulbs for $2.15 just to try. I was so impressed with the performance I decided to forgo building led replacements for the time being although it would be an interesting project. The web site offering information on these bulbs is
www.ibmwr.org/ktech/taillite.shtml For those of you interested in doing an led upgrade, I will mention some low cost leds my son obtained to build a light bar headlamp. He mounted it on his safety helmet when he rides his mountain bike offroad at night.
He purchased components manufactured specifically for the mag flashlight manufacturing industry. He mounted three of the fairly high power leds on a horizontal bar/heat sink. On the center led he attached a conical reflector providing a 10 deg beam. On the two end leds he attached reflectors focusing to a 30 deg beam.
The leds were wired in series, and powered by a 12v battery fed through a resistor to limit the supply such that each led had the necessary 3.5v. The battery (I don't remeber the type) weighed about a half pound and will power the three lamps for approximately 4 1/2 hours. A single led of this type is so bright it can't be viewed directly by an unprotected eye.
Each led cost about $6.00, and the lens were about a buck each. If I decide to procede bulding a led setup at a later date, these will be what I use.
The tail light function can be provided by three leds driven as I have described, but at a reduced brightness obtained by using a series resistor and a blocking diode. A brightness increase for stop light function can be obtained by applying 12v through another path consisting of a blocking diode and perhaps a smaller value resistor. By removing the existing incandescent bulb socket and fabricating a mounting bracket/heat sink for the leds the housing can be converted for leds with a small dose of ingenuity. If any of you bolters are interested, I can provide the web site from which product information and specs can be viewed, and from which parts can be ordered.
meansam