Optics for Custom Headlight for Harley Chopper


Newly Enlightened
Apr 21, 2009
Hello all,

I'm working on making a custom Headlight for the chopper I'm building (1978 FXS). The idea I had was to have (12) 10w Cree XML-6 arranged around the inner edge of the headlight firing back into the reflector. 6 to 8 would be on for low beam and all on for high beam. I'm wondering what the optimal reflector design would be or at lease look like and what type of lens should I be looking at for optimal throw? I'm trying to keep the headlight outer diameter under 6 inches and the exit window of the headlight at least 4 inches.

If you need more information to go on, please let me know. I included an picture of the inner emitter ring.



Mar 26, 2004
Sorry, no good. It is not possible to make a homemade headlamp that is safe, effective, or legal (let alone all three). It takes a huge amount of specialized knowledge and equipment to design an acceptable beam pattern; it's not something you can just throw together on your workbench.

There are numerous legitimate LED headlamps you can install on your Chopper. Some of them are quite excellent.

Steve K

Flashlight Enthusiast
Jun 10, 2002
Peoria, IL
For a road vehicle, Virgil's response was expected to those who've been on CPF for a while.

For a any other application.. the idea of having the LEDs hidden is intriguing, but I'm at a loss to imagine how a reflector could be designed that would combine the light from all of those LEDs into a single beam. Is such a thing possible? Are there any examples in production?

I have seen bicycle headlights that have an LED mounted near the top of the light and firing down and to the rear, with a reflector that manages to arrange the light into a very nice beam that complies with industry standards. Doing this with one LED and one reflector seems much more possible than an array of widely spaced LEDs and a single reflector.