Horn/relay article

[jsf14469]

Lost January issue of ON with horn/relay article. Looking for that article and advice about mounting a loud horn for 1971 R75/5. Would like to retain stock mount.

[20774]

The article dealt mostly with wiring, especially including relays. My guess is that loud horns will require a relay so that you don't fry the smaller wiring and components in the current switches. An article on relays is here:

http://www.airheads.org/content/view/159/98/

The other thing the article mentioned was mounting the horn with some kind of flexible mounting. This lets the horn vibrate and resonate. The Fiamm horns typically come with a stand-off bracket that is compressed of numerous flat pieces of metal, almost like the thicker blades in a set of feeler gages. Each end of the bracket is held together so the whole thing doesn't fall apart.

The bracket would be mounted somewhere towards the front near the downtubes. Most pictures of the /5 show it mounted directly in the middle of the bike between the downtubes.

[kwb210]

I have Fiamm horns mounted on my 77 r100, bike is new to me so I do not know about any relays being included in wiring. I appreciate your bringing this up as I am making a list (and checking it twice) for some wintertime maintainance. This will now be on the list. I do wonder what the impact of a short horn burst would be on the wiring. Depends on ones usage of the horn! While traveling in India EVERYONE uses their horn, its a friendly motion, hey here I am, notice me. Most would just honk honk every so often (quite often actually) but some drivers would use their horn the entire time they wre driving, it was never or rarely a negative motion like here in America.
Kurt
new to me 1977 R100/7

[jsf14469]

Gentlemen:

Thanks for the replies, especially relay article. Will see if I can digest all that info.
Will installing relay to get more current to the horn make that horn louder or burn it out? Another car pulled out in front of me on commute to work. Do not know if current horn even wakes these drivers up.

[sumran]

A properly functioning set of Fiamms will get plenty of attention. You need a heavy circuit (12 or 10 gauge), preferably wired directly from the battery. I fused mine to protect the wiring. Some view the horn circuit as an emegency item and therfore, do not fuse them. They won't blow the fuse unless the horn is stuck or there is a short in the wiring, so I went with the fuse.

The relay is nothing more than a switch for the circuit, activated by the horn switch. The horn switch can't handle the amount of current the horns draw. The horns will not be damaged by this. As long as they are receiving the correct voltage, they will be fine. It is a resistive load so the current flow is self regulating.

[shire2000]

My 1981 R100RT came with dual Fiamm horns from the factory. I rewired the system, installing a good relay and 12 gauge wire direct from the battery with an in line fuse. They got much louder. Was well worth the $15 and 20 minutes work to do it. I was originally thinking of installing a set of air horns, but once I did this, I don't feel I need anything louder.