Dual Horns on an R1100RS
by Rob Lentini
I finally go off my butt and mounted dual Fiamms on my R1100RS. There is a PERFECT mounting location for them under the left fairing panel. No modifications, no hole drilling, no bending, no kluging is required–just what I like.
1. Dual “snailshell” Fiamms with two terminals each, dual tone, available at discount auto stores for about $9.95 each (or your dealer for much more).
2. One 8 X 50mm socket head bolt with washer.
3. One 8 X 20mm spacer for the above bolt (or you can stack washers–but this is NOT anal!).
4. Wire and spade connectors to extend the stock horn connection to your new location.
5. Plastic tie straps
1. Remove left fairing panel (requires both seats to be removed).
2. Remove stock horn and throw is as far away as you can! :-):-)
3. Remove the 8mm bolt that secures the fairing support to the steering subframe. This bolt is visible near the wiring harness. It is the only bolt of this size in the immediate area.
4. Install your new horns using the provided brackets. Slip your new 50mm bolt and washer through the brackets, install the spacer on the bolt, and screw in the new assembly into the subframe 8mm hole. Align both horns with the snail shells to the left, terminals aiming in, and bellmouths aiming down and slightly forward (for best sound and least moisture ingestion). Looking from the left side at the bike, the rear horn bracket should be at about the 2 o’clock position, and the front at about the 10 o’clock position. In other words, the front horn is forward of the 50mm bolt, and the rear is aft of it. Also align both horns to be about 5mm or so from the bottom of the fuel tank. After you have done all this, check fit the left fairing panel. You should have plenty of clearance like mine did. This location looks stock and the horns really BELLOW from here!
5. Now wire up the horns in parallel using 18 gauge or larger wire. A relay is not required (there is already a horn relay on the bike). Tidy up the wiring with plastic tie straps.
6. Careful now!!! Test the horns. If you got the same model as I did, they will damn near knock you over!
Have fun waking up the snowbirds! Just don’t rely on horns for your total safety.
Horn Installation on R1100RS
by Dave Thompson
I purchased a set of Fiamm clones (“Candlepower Horns”) at Cycle City in Palo Alto. They are practically identical in appearance to the Fiamms I installed on my Paris-Dakar, and come with the same hardware (four mounting straps and a relay).
Installation: (all wiring is 14 gauge, and I soldered all connections)
As with the P-D, the most difficult part was deciding where to mount them. In the end, I decided to mount them inside the fairing, on either side of the headlight. There is not much room inside the fairing, so it was not easy to find a place to mount two rather large horns. I doubled up the mounting straps for strength, then bent them to a 90 degree angle about 1 inch from the end which mounts to the bike. I fastened the strap to the horn. I then removed the bolts which hold on the oil cooler (one at a time!) and placed the mounting strap under the frame attachment point. I bolted the supplied relay to a hole on top of the wiring junction box in the left upper fairing.
To wire them up, I removed the stock horn, and noted that the green/brown wire went to +12 V when the horn button was depressed. I then ran the stock horn wires to the supplied relay. (The bike already has a relay for the horn, but the wiring was simpler if I just had the BMW relay drive my relay. I don’t know how tough the BMW relay is, either.)
I then pulled out the battery and attached a wire to the hot terminal, ran it through a radio shack inline automotive fuse holder with a 15A fuse, and ran that wire alongside the main wiring harness to the new relay.
I believe that one difference between these horns and the Fiamms is that they ground through the mounting strap. On the P-D, I ran a separate wire to ground the horns, since the crash bars were not well grounded. I did not have to do this on the R1100RS, since the mounting point seemed to be well grounded.
That’s all there was to it. It took me a few hours, since I took off the fuel tank. This is NOT necessary, and I strongly recommend against it.
p.s. yes, they are loud!