THESE ARE NO LONGER IN STOCK. IF THERE IS SUFFICIENT INTEREST I WILL MAKE SOME MORE
One of the first mods I did to my Bonnie was to upgrade the horn which like all stock motorcycle horns (except BMW), is pathetic. Years ago I installed a pair of Fiamm horns and a relay on my Ariel in order to deter Volvos, tour buses and sheep from wandering in front of me. I wanted the same attention getting capability for the freeways and blind mountain curves of California. Being cheap, I acquired a random set of "snail" horns on eBay, and ran up some brackets and wired them up. I figured that anything with a megaphone horn profile is going to be most effective if it is pointed at the target without obstruction, so I mounted them up front and facing front. To camouflage all that fugly black and red plastic I covered the inside cover with aluminum tape and carved a reflector to fit the outside.
This bodged together prototype has drawn admiring comments from several other Bonnie owners, so I have tidied up the installation and I am offering this setup as a kit with all the components needed to install on the New Triumph Bonneville and T100.
Kit includes:
Here are some pictures of what the installed horns look like.
|
Side View
Note the horn shaped horn profile and how it echoes the curves of the headlamp ear and indicator. The grille lines up perfectly with the seam of the headlamp shell.
Answers to likely questions:
Q: Why should I upgrade my horn?
A: The whole point of having a horn is to attract the attention of other road users and let them know you are there, in the hope that they are just inattentive and not deliberately trying to kill you. To do this effectively you need a strident tone that will make them instinctively look in the direction of the sound. The standard horn is too weak to do that reliably in many road conditions, particularly if the other road user has the windows rolled up on their Pinto and is head-banging to "Bohemian Rhapsody". Yes, Wayne, I mean you.
Q: I've seen single snail horns advertised as 130dB. How come yours are only 112dB?
A: Short physics lesson. Decibels measure the relative intensity of two sounds. Every bel (ten decibels) represents an increase in sound energy by ten times. In the case of applying this to a thing, such as a horn, the standard measurement is relative to (something really quiet at the verge of human hearing) at a distance of one meter (about 40 inches). These 130dB numbers are measurements taken at four inches, not forty. Due to the inverse square law, if you move your ear ten times closer to the source of a sound, the sound intensity is increased a hundred times. A hundred times is the same as ten times twice, so it gives you and extra twenty on your dB number. In fact all of these snail horns produce about 109dB. If you double the sound intensity by adding another horn you add 3dB, hence the 112dB rating on these horns. Some sellers use the four-inch +20dB number because bigger numbers make them appear louder in their ads. It's pure marketing. I majored in fizzix at Scotland's #1 party university, so you can trust me on this.
Q: What do they sound like?
A:
These sounds were recorded using a laptop at about ten feet. The first sound is
the stock horn, the second is the Alpex horns. They were recorded at the same
time. The only editing was to remove the silence between the honks where I
switched the wiring. In real life the volume difference is even more noticeable.
Q: Why does the kit include a relay? Why not just plug in where the old horn plugs in?
A: The standard horn is rated at 3A. The circuit and horn button are designed around this load. The 10A fuse is shared with the flashers and brake light, which will draw about 4A when they are on at the same time. The Alpex horns are rated at 8A. Wiring these horns directly to the standard horn wiring would potentially blow the fuse on this circuit. Upping the fuse is always a Bad Idea. While it has been said that the resistive heating in the wires caused by overloading the circuit would be insignificant with an intermittent use like the horn, that resistive heating represents voltage drop in the wiring, meaning less volts at the horn, and a less than efficient horn - which defeats the point of upgrading the horns in the first place. Ohms law. Fizzix. Relays are good. Trust me on this.
Q: Why should I buy your kit and not make my own? I can get horns like these for $20 at Pep-Boys.
A: Probably not with the oval chrome grill and chrome covers. Once you factor in the materials for the brackets, the wiring, the loom, the connectors and the reflectors etc, etc, and your own time where you could be riding and you are likely going to end up either out of pocket or with something less in tune with the aesthetics of your Bonnie. But go ahead, I'm not stopping you. These kits are for people who do like to bolt on things designed and build by others rather than those who like to scratch build their own parts and have the wherewithal to do so.
Q: I want to make this kit myself from parts I can get at Pep Boys and Home Depot. What are the exact dimensions of the brackets?
A: Send me $50 and I will mail you a couple.
Q: Does this kit involve me cutting or tapping into any wires on my Bonnie?
A: No. It plugs into the little-used pigtail meant for the auxiliary socket. This is a 10A fused circuit.
Q: What about my auxiliary socket?
A: The harness includes wiring to feed power to the auxiliary socket when the horn is not in use. This wiring is made live by replacing the four pin relay in the kit with a five pin relay. Just unplug one and plug in the other. Power to the auxiliary socket will then be powered except when the horn is used. Your heated butt-warmer will not notice the brief loss of power.
Q: Why don't you supply a five pin relay?
A: The horns come from the manufacturer with a four pin relay. Most people don't need the five pin as they don't have an auxiliary socket. If there is enough demand I will look into getting the relays wholesale so I can supply them as an option and save you paying auto-store prices for it. Most US and European cars use these Bosch style relays, so you can probably pocket one next time you are are at the scrappy.
Q: Why not wire it direct to the battery?
A: It would need longer wires and an inline fuse. This would cost more in time and money to produce, and you'd have another fuse to worry about and carry a spare for.
Q: What about the America, Speedmaster or Thruxton?
A: I don't have one of those, but I know this kit will not fit as the headlamp mountings are all different. If you want to ride over to Livermore, CA sometime and be a guinea pig, we can talk discount.
Q: Why does the kit run grounding wires to the horn mounts when the bracket is metal?
A: Check the wiring on the Bonnie. In no place does Triumph use the motorcycle chassis as an earth return. Even the engine has a grounding wire. None of the electrics are grounded to anything forward of the steering head, as far as I can tell. The chassis is not designed to be a circuit ground, so I'm not going to rely on it to ground 8A back to the battery for me. Coventry/Meriden Triumphs and most other old Britbikes do use the frame and forks for grounding everything. These machines are not famous for reliable electrics!