Here's the recipe:
Obtain the following parts, available at HD or Lowes or any Hardware
- 1 aluminum 36" square tube from Home Depot.
(I made 2 lightbars for 2 bikes out of it - a C10 and a Voyager XII)
- 2 beam clamps (electrical section I believe) Less than $2 ea.
- threaded rod to match the beam clamp holes - enough length to reach the bottom bar of fairing stay (see text below).
- 4 regular nuts and 6 washers to fit threaded rod.
- 2 nyloc nuts to fit the threaded rod.
Holes in square tube for threaded rod mounting are 3 3/4" apart measured O.C.
The threaded rods are 4 3/16" to 4 1/4" long. There is some adjustment available in them depending how far up you thread them into the beam clamp and how thick your washers are on the bottom. Measure twice cut once! Run a nut onto the rod BEFORE you cut it with a hacksaw or dremel tool. Then you can lightly dress up the jags of the cut on a grinder, backing the nut back off to straighten any thread boogering.
The bar itself is 19" long. This could vary for you depending on the size of the lights you select.
To get the holes right for the rod, cut the tube to length, measure and marked the exact middle of the tube. (9.5" for mine).
Then I measured half of the 3 3/4" to the left and right of the center mark at 1 7/8" each way.
Use a point punch to make the holes exactly where you want them, centered on the tube.
I used stainless hardware whenever possible due to weather exposure.
Assemble as shown in pic:
http://rides.webshots.com/photo/2324963860089716678OgEjAi?vhost=ridesThe beam clamps fasten the assembly to the bottom front bar of the fairing stay. I believe that part of the fairing stay is the same for all C10's. Measure first so you are sure to get the right length threaded rod. I don't remember if I had to remove the fairing access panel on the bottom for this to fit, its been a while. With ratchet drive extenstions, I was able to get a socket wrench on the beam clamp screws without removing any inner or outer fairing pieces. Just had to turn the handlebars just right to provide a straight shot.
I also went to the trouble of drilling holes and running the wire to the lights inside the square tube to keep it neat. That was the biggest job of the entire project.
Its worked out for over 5 years for me, and it cost about $30 - $35 for each of the 2 bikes including the lights.