Question: Does anyone have experience with these fork-mounted auxiliary driving lights:

I have a pair of these Bosch lights that fit a K100 but can't locate any drawings. The brackets attach round the front forks and utilize a bolt hole on the triple tree to keep from sliding down.

---

To retrofit the RT some modification is required as the lights move with the front forks. The rubber fork boots have already been removed to increase air flow under the fuel tank, but there remains a boot bracket on the radiator grill that will also have to go.

I am not sure that having them attached to the forks there would be too successful on an RT. One of the guys on the Motobrick forum had a bracket that picked up on the fairing mounts and came out either side just under the fairing with the lights mounted hanging down from the bracket.
I mounted my spotlights up on the fairing where the police mount the red and blue lights, there are a couple of places that are meant to take them with a bit of extra webbing around a thicker area.

They do work very well but it depends on weather or not you are prepared to drill some 3/8 holes and make some brackets to mount them.

It seems the Bosch road lamps were a dealer item. Many German-made cars of the era had Bosch fog lamps (e.g. Mercedes, Porsche, BMW), heck I even had a set of dealer installed Bosch fog lamps on my '87 Nissan Pulsar. So, it's not surprising that Bosch prepared a set of drive lights for the K-series (shown here on the K75), but judging by the lack of response on this form it appears they're a scarce item.

Looking at the brackets (below) they appear to be made-up of three pieces;
1) Lamp Arm
2) Shoulder
3) Tube clamp

As shown here, the arm is braised to the shoulder, while the tube clamp completes the installation.

Now, looking at the original installation (below right) it's clear the bracket mounts to the upper brace of the triple tree. In addition, bolt hole a) also lines-up to mounting point on the upper brace, this is what keeps the bracket aligned and properly orientated.

Notice now that the bracket on the right has an additional clip b) braised just above the alignment hole. Looking at the triple tree itself (above left) it becomes clear that somewhere along the line the bracket was modified to fit the lower brace because the bolt hole b) is higher up on the brace.

I will post some drawings of the brackets in case the reader may desire to fabricate some of their own. Common sheet metal could easily be pounded into a shoulder to fit the brace, while a tube clamp is easy to make. The only bit that needs some detailed attention is the lamp arm itself.

OK, so next step is to acquire road lights.



(above left) These are the lights it came with, note that one is a fog light and the other a road light. Fog lights spread the light out widely, and are not of much use in this installation. Such fog lights are similar to those installed on 80's era Porsche, BMW, Mercedes, etc. and are fairly common. Road lights, on the other hand, are quite scarce. After an intensive search one was located on e-Bay.eu (right), this for a vintage Saab.



Finally, today, the Saab lenz arrived (left), and installed into the lamp holder (right). So, now we are ready to take the next step--to install the brackets.

I do have the same lights on the bike with the sidecar, but they didn't work (chopped wires)
Tomorrow I will be taking the bike out of my basement and will re-assemble it in my driveway.I hope that I will be able to test them during the week.
The way that I wired them is as follow:
fog light is only working with the low beam
Driving light is only working with the high beam.
If needed, I can turn off the auxiliary lights.
The only electrical requirement was 2 relays and one switch.
I believe that I had posted a electrical schematic, but if needed I can send it to you.
I can also send you pictures of the original mounting.



CF

Crazy Frog wrote:I do have the same lights on the bike with the sidecar,
The way that I wired them is as follow:
fog light is only working with the low beam
Driving light is only working with the high beam.

Oh ya, I remember your wiring diagram! The lights look real good against the black faring--but you're mounting them down on the wheel.

What I didn't realize till now is you're using a fog light on the one side and driving light on the other. Most curious.

I'll be going with an OEM style wiring harness, and just waiting for the relay and other parts from Eastern Beaver. I'll post a wiring diagram and form board very soon. I engineered wiring harnesses for Boeing for a number of years, and whether for an aircraft or motorcycle, the design principals are much the same.

(Note: I see many complaints here about the lack of wiring information here and am almost tempted to purchase an old wiring harness on e-Bay just to create some good form board drawings for people to follow.)

OK guys who has a complete wiring harness that AJ can dismember for the benefit of all K kind.

---

(above) The lights themselves draw 9.16 amps, so a 15 amp fuse should suffice. Accordingly, the wiring will be rated for 15 amp service per table at right. The main lighting circuit includes a 40 amp aux relay in conjunction with 14 gauge wire that is also rated at 40 amps. Individual lights will use 16 gauge wire for added flexibility, but this is still OK because 16 gauge wire is rated at 20 amps. Control circuitry will use 18 gauge wire, an existing switch on the dash board, and switched power from the relay box such that the lights can only be activated when the main headlamp is on.

OK, let's get to work on a form board.

First step is to remove the fuel tank as that's where the wire bundle will run.
Next, get some string and run it through the bike where the wiring will go, cutting to length. One piece of string is used to simulate one piece of wire.


(above) Now, lay the string down on a flat piece of cardboard to simulate what the bundle will look like. Set your hardware down also to get a proper perspective. At right are the drive light connectors and at left is the relay and fuse plug. At center is the ground point, while the string running up and to the right simulates the wires to the dashboard switch. Note, the latter wiring is already on the bike and it will terminate at the white connector at center of picture.

Now, cut each piece of wire using the string as a guide, then wrap the entire bunle up with cloth tape. Cloth tape is prefered for flexability and unlike ordinary electrical tape it resists heat cracking.

www.postalpaperantiquities.com/Pages/Temp/FormBoard2.jpg

(Above) When the wire bundle is completed, lay it back down on the form board to check the fit, then draw lines along it's length and mark the wire colors, etc. A relay drawing is used to indicate wiring instructions.

www.postalpaperantiquities.com/Pages/Temp/FormBoard3.jpg

(Above) Now remove the wire bundle and carefully measure the lengths of each branch of the wire bundle.

A completed formboard drawing will be published at the end of this thread.

Next, we install the wire bundle into the bike.

A. Start by feeding the bundle through the front faring and then under the tank.

(Above) Wiring goes under the front lip of the faring and under the faring mounting bracket, and when complete these connectors will be tie-wrapped to the faring mounting bracket.

A. Splices at the back of the main connector covered in cloth tape. These splices help reduce number of wires running through the bike, thus saving weight and reducing complexity.

Now, route the wire bundle under the tank area.

(above) See how small the diameter of the bundle is!

B. The branch of the bundle where switch harness (white connector) and ground points intersect.

Continue routing the bundle back into the relay box.

(above) Note how easily the bundle fit's into existing rubber seal at front of the relay box. It's also not to hard to find a place for the extra relay and fuse plug within the center of the box. Unfortunately, there is no external fuse connection, so servicing will require removing the tank.

C. Main power is obtained from the relay at the back of the box. No need to go all the way back to the battery.

The mounting brackets come next. The tolerances under the faring are fairly close. The rubber boot and boot gasket had to come out, but these are already removed on most bikes to increase air flow under the tank. In addition, the cold air scoops were removed (but if these had done the job as designed there would be no need to remove the boot).

Next the exension tabs were welded onto each of the brackets.

Upon fitting the brackets to the forks it was discovered the tops of the tabs (above) had to be drammeled round (red lines) because they were interfering with the faring bracket.

The rest of the job is fairly routine, just creating the connectors and leads going to the lights themselves. A 16 guage wire was used for flexability, and wrapped with cloth tape. There are tabs on the underside of the bracket for wire mounting, but to avoid pinching the wires I simply tye-wrapped the bundle to the tabs.

And, here is what everyone is waiting for, after a 50 mile road test and rough adjustment this is what the final product looks like:

The road lights are bright, so bright they cannot be photographed head-on. They are 55w each, the same as the head lamp, but in a much smaller package they appear brighter. Vibration is fairly minimal, after they were properly tightened the lights were very stable. The brackets are also very high-up the forks where there is virtually no chance of bottoming out.
This is the first time I believe these lights have been adapted to an RT, and it appears to be a great success. They look very good and don't affect stability at speed. There is at least one other pair on e-Bay right now in case you are wondering.

good onya aj
nice job

Nice!!!