I recently purchased a 2009 Suzuki DRZ400S, a street legal dirt bike motorcycle, but I was thoroughly disappointed with the factory headlight. Both the low and high beams were very dim. I have experimented with several inexpensive LED light bars from Amazon with good success so I purchased a 7-inch wide, single row 18W LED from Nilight. I picked up 2 of these LED light bars for $15 and the quality seems pretty good.
I did not want to drill holes in my factory fender or fairing to mount the LED light bar so searched the web for some type of mount. I found exactly what I needed with a mount manufactured and sold by JNS Engineering. JNS sells the mount for approx $40, which is a fair price, but since I enjoy the DIY approach I set off to make my own.
Step 1: Removing the Front Fender and Factory Reflector Bracket.
Using the JNS mount design as my inspiration, I removed the 4 bolts from the bottom side of the front fended, which holds the fender to the triple-tree. With these 4 bolts removed, I dropped the front fender and let it rest on the front wheel. Then I was able to remove the thin metal bracket that holds reflectors to each side of the front fender.
Step 2: Tracing the Mount.
I have a good selection of tools, but I did not have a way to cleanly cut sheet metal so this led me to look for some other material for my DIY mount. I've had some experience using starboard to repair boat hatches, which led me to look for some type of poly material. I did a quick web search for poly boards and found a black cutting board at Target for $14.
Once I had the black poly cutting board, I then used the factory reflector bracket as a template and a silver Sharpie to trace a pattern onto the poly cutting board. I took extra care to leave an additional 1-inch of poly board at the bottom of my design to serve as the perch for the LED light.
In one of the photos, you can see where I used the width of the ruler to add the 1-inch of space where the LED light would be mounted. In hind sight, this was not too much additional space so 1 1/2 to 2 inches maybe suitable...depending on the size of the LED light bar you may be using.
Step 3: Cutting and Drilling the Mount.
Once I had the pattern for the LED mount traced onto the black ploy cutting board, I used my handheld grinder and a cutting wheel to make the cuts. If you have a ban saw, tabletop scroll saw, or maybe a jig saw (preferably with fine tooth blades), these might also lwork.
I've had good success cutting plexi-glass or acrylic sheets using the grinder so this was my tool of choice. It is important to note that the grinder and cutting wheel will cause some melting of the poly board. If you happen to get any of this molten plastic on you, its not fun. The melted plastic sticks like glue while its leaving a lovely burn mark. I used a sturdy knife to trim the edges once my cuts were complete and plastic had cooled.
Then I used a standard drill to make the 4 bolt holes in the new LED mount.
When I was checking the fit of the new mount against the bracket with the reflectors attached, I had a bit of clearance issue, as noted in one of the photos. I used the silver Sharpie to mark these spots on both sides of the mount and then notched out these spots with the grinder. Then she fit like a glove.
Step 4: Installing the Mount and Front Fender With Longer Bolts.
Since the poly board has a depth of approx. 1/2 inch, the 4 factory bolts from the front fender were now too short. As noted in the attached photos, the factory bolts were just long enough to extend past the new mount and reflector bracket. I found a longer set bolts at Home Depot. Of course these bolts were metric and the specs on the package were noted as M6-1.0 x 30MM.
Using the longer bolts, I test fit the new LED light mount, reflector bracket and front fender. Everything worked like a champ.
Step 5: Assembling and Mounting the LED Light Bar.
As noted in the attached photos, once installed between the reflector bracket and the front fender, the new mount was not perfectly horizontal. The new mount had a slight incline due to the rake of the front forks.
Fortunately, the mounting bracket and hardware that came with the 18W LED light from Nilight helped with this geometry issue. As detailed in one of the attached photos, the mounting bracket was asymmetrical and notched deeper on one side. I installed the bracket with the deeper notch closest to LED light. This allowed the bracket to pivot slightly more than 90 degrees and allowed the LED light to angle slightly downward, which offset the slight incline of the new mount.
I test fit everything on the bike, marked the location for the LED light bracket, and drilled a hole.
Step 6: Wiring the LED Light Bar.
I chose to wire the new LED light bar to the existing low/high beam switch on my DRZ. As noted in the attached diagram, the back of the factory headlight has 3 prongs. The prong on the left (driver's side) is the negative, the prong on top is the low-beam positive, and prong on the right (passenger's side) is the high-beam positive.
I first remove the plug from the back of the factory headlight. Then, I ran the negative wire from the LED light to the negative prong on the factory light and the positive wire from the LED light to the high-beam positive prong.
Each prong on the back of the factory head light had a small hole so I simply fed the bare wires from the LED light through these holes. Then I reinstalled the factory wiring plug. Now the LED light bar only turns on when I switch on the high beam.
The additional light makes a world of difference.