LED headlight conversion
Posted: Wed Sep 13, 2023 4:12 pm
I was less than pleased with the headlight performance on my 1979 Honda CBX motorcycle. It wasn’t very bright and it was a little bit warm (yellow). I decided to investigate converting to an LED. I was unable to find an already made kit for the conversion so I did a little search for an LED that would easily fit. I searched forums for info but found that many suggested options were no longer available. Although there may be many other other options (and maybe even better ones), I settled on part number H4-HLV5 from Superbrightleds.com. As of 8/23 they were priced at $69.99 for a pair which means they are $35 each. Of course the CBX only needs one but I thought I could use the second one for another bike. They also had the H4-HLV4 for $59.99 and the H4-HLV8 for $39.99. As I wanted white light (not blueish 7200K), I passed on the H4-HLV4. The H4-HLV8 looked like it would do the job but it also looked a little larger in the heat sink area so that’s why I picked the H4-HLV5. Whatever you get, make sure it has an H4 base. BTW the stock incandescent lamp is a Phillips 12593. The conversion was simple.
Before I converted, I took a picture of what my original incandescent headlight looked like from the rider position. LowHi
There was a noticeable but not big difference between low and high beam. The following is what the LED headlight looked like in the same place and time. LowHi
Installation was easier than I expected. Note that my headlight bucket is a chrome metal one. It my be a bit different from the original but I don’t know. I was curious about power consumption numbers for both types of lamps so I made the following measurements. Going with LED certainly saves power which should make the expensive alternator happy especially considering the daylight running headlight. If you use the H4-HLV5 LED, you will need to do a little extra work to fit the wire bail that holds the lamp in place. As can be seen in the following picture, the bail will not fit over the LED heat sink. This problem can be solved by moving the heat sink away from the base by removing the hex set screw as shown below. The bail can then be placed over the lamp base. The white grease is heat transfer compound. Don’t wipe it off and don’t worry if you get it on you. It’s just zinc oxide in a silicone base. The lamp has a simple facility for adjusting the beam angle. Simply grasp the silver lamp base and rotate the black heat sink in the desired direction. The detent ball will pop into the desired hole. I found mine to need no adjustment. The original incandescent H4 base lamp looks like the following: I have been very happy with the result of this modification. The light is brighter and whiter and I can see farther down the road.
BTW - If you get the idea of wiring the bike so that both beams come on together, either when selecting hi or continuous, that’s a good idea but not wise. The heat sink will not be able to handle the extra heat and the LEDs will eventually fail.
Before I converted, I took a picture of what my original incandescent headlight looked like from the rider position. LowHi
There was a noticeable but not big difference between low and high beam. The following is what the LED headlight looked like in the same place and time. LowHi
Installation was easier than I expected. Note that my headlight bucket is a chrome metal one. It my be a bit different from the original but I don’t know. I was curious about power consumption numbers for both types of lamps so I made the following measurements. Going with LED certainly saves power which should make the expensive alternator happy especially considering the daylight running headlight. If you use the H4-HLV5 LED, you will need to do a little extra work to fit the wire bail that holds the lamp in place. As can be seen in the following picture, the bail will not fit over the LED heat sink. This problem can be solved by moving the heat sink away from the base by removing the hex set screw as shown below. The bail can then be placed over the lamp base. The white grease is heat transfer compound. Don’t wipe it off and don’t worry if you get it on you. It’s just zinc oxide in a silicone base. The lamp has a simple facility for adjusting the beam angle. Simply grasp the silver lamp base and rotate the black heat sink in the desired direction. The detent ball will pop into the desired hole. I found mine to need no adjustment. The original incandescent H4 base lamp looks like the following: I have been very happy with the result of this modification. The light is brighter and whiter and I can see farther down the road.
BTW - If you get the idea of wiring the bike so that both beams come on together, either when selecting hi or continuous, that’s a good idea but not wise. The heat sink will not be able to handle the extra heat and the LEDs will eventually fail.