njkayaker

Nothing is perfect. That collisions still happen doesn't mean that some of them can't be prevented with a horn.

No driver is really going to notice a tiny camera. It's a worse idea to prevent collisions than a horn is.

Horns are a common noise that is often used to indicate that another driver is getting too close. It often is enough to prevent drivers from getting closer.

A camera is pretty-much useless for preventing collisions. If drivers don't notice the cyclist, they certainly won't notice a camera.

njkayaker

The distance between the horn mounted at the front (a better location) and the button is so short that going wireless adds complication for a minor benefit.

fietsbob

An air compressor, to substitute air for steam , allows a guy in town here to have horns off big ship's stacks,

on his camper shell of his pickup-truck..

angerdan

The next level after Loud Bicycle Loud Classic and Loud Mini is this very compact motorcycle air pressure horn (Screaming Banshee Motorcycle Horn System Version 4).
The ad text already sounds promising: "The Screaming Banshee Shockwave is the loudest and best engineered motorcycle horn you can buy". +130dB for $120:
https://screaming-banshee.com/products/banshee-horn

VegasTriker

It should be relatively simple and cheap to buy an aftermarket horn meant for a motorcycle and power it using a 12v lithium ion battery pack or even a home built one using four li-ion 18650 batteries. If you order one from China they are as cheap as less than $3 for a 110 decibel, 12V DC, 1.5A horn. All you would need is wire, a momentary contact switch, and a battery to complete the package.

HOWEVER before you do this you might want to think twice because you might be damaging your hearing at the same time. It only takes a short exposure to 100+ decibels to begin the process of destroying your hearing. If you were to mount the horn behind you on the bike, it would be even worse. You are never going to be more than a short distance from the horn no matter where you mount it.
"What Counts as Excessive Noise? Frightening fact: Hearing loss can occur after a one-time noise exposure at 120 decibels, such as gunfire, or continuous noise exposure to dangerous levels of 85 decibels or above over a prolonged period of time. (copied from the Huffington Post article on 10 Common Noises That Can Cause Permanent Hearing Loss) I know from experience having ridden a motorcycle for many years and only started using hearing protection when it was too late.

I tried the Airzounds horn (bought two of them) but abandoned using it because the mounting system is pure crap for a device that costs more than $30. I still have it on an older trike that I no longer ride but had to cobble the mounting with a length of cut up bike tube to keep it from falling off. These days I use an electronic bike horn. Slightly less loud compared to the Airzounds but far cheaper and the mounting is far better. The batteries last more than a year and I don't need to fuss with pumping it up.

Milton Keynes

I don't think a car horn is loud enough. You need a horn from a locomotive.

angerdan

You're right, but it's not conveniant for tandems and kid bikes
So if 113dB are not enough, 120dB could fill the gap:
SoundBomb Horns - DENALI Motorcycle Electronics

PdalPowr

Imagine using that bike to sneak up behind people taking a shortcut through a railroad tunnel.
One good blast and a bright light would see another guinness world record broken.

2_i 

I have this 6-12V horn on my bike. The reason I use this particular one is that all my power on the bike runs off 6V and I found that I could not drive horns with nominal 12V voltage at 6V. The particular one I chose can be actually driven even at 5V USB.

The horn does wonders in the streets in alerting drivers to my presence and negotiating the right of the way. The sound is that of a car alarm and the horn toggles over 6 versions or so of these. In the past I banged the cars and yelled. Now I just push the button and wait. Usually I do not need to wait until the second version of the sound.

The only negative I can think of is the lack of any coating on the PCB inside. After a year of riding with the horn and some very heavy rains, the sounds became muffled and erratic. I took the PCB out and coated it and all is good.

MikeyMK

I have a 17in air horn. I recon it'd go along the top tube without getting in the way. I'm just not sure how to power it. I could use pump and battery but the battery would be heavy. I could use a compressed air can. Or i could use a bike pump - it'd take one second to draw and compress, and that'd be enough of a toot.

MikeyMK

PdalPowr

It is neat looking that is for sure.
Too bad it doesn't fit over the front fender.
It would look even cooler.

Good luck with your project.

2_i 

Here is mine

MikeyMK

Well I've got a 48v-12v converter in the post so I'll have endless 12v power for it. It's for the front lamp and only 60w though, so i don't know if it'd power a suitable compressor.

Shorter ones are available, that'd fit on the fender, but I think I'm gonna go for a conventional car horn if i can find one under 60w.

PdalPowr

With the caveat that under the hood car horns are not going to be pretty.
The more recent the model of car,the more likely it is going to be low wattage.
If you don't mind going used a used car parts place or scrapyard will be able
to help you out. A car horn wouldn't go for much as it is rare someone would need one.

MikeyMK

I've got quite a few from my car projects, and i'd wanna use the lower tone one from a pair (and tweak it to just the right note). But those ones are snail-shell style.

I'd like one like this. I could probably find a cover, or make one, for a conventional single-tone open plate. But as you say, these are likely to use a bit more juice - i've seen figures of over 70 watts for this type, but i don't know if that's each, or the 6v version, or...

PdalPowr

Well that is not ugly but is not as pretty as a bicycle.
You know I bet that would fit underneath the seat.
It would be out of the rain,inconspicuous and
as long as the vibration doesn't cause impotence would be darn loud.

You know all you would need is a switch,mercury switch,relay and
it would serve double duty as a crude bike alarm.

Wanderer

A friend of mine has real train horns on his motorcycle.

BIG and HEAVY!

When he hits the horn button, it really gets exciting!

ItsJustMe

One thing that I discovered when hooking up a car horn in a stage prop - car horns are ridiculously electrically noisy. They are basically spark gap transmitters and they shove a huge amount of hash back up the power lines. I measured about 80 volts of noise getting crammed back up the 12V lline when I put my scope on it.

If you just have a separate battery for it and use a switch or relay, you'll probably be fine. You should at least put a diode in parallel with it to clamp the flyback voltage, even with a relay, to keep from frying the relay contacts. But if you use a battery that's also used with electronics, I'd be very careful about the noise, perhaps put the horn or the electronics behind a noise filter.

surak

PdalPowr

"I hear that train a'comin'"

The best part was actually when the compressor kicked in.

u235

You beat me to it. Saw that and immediately thought of this thread.

Milton Keynes

Something like that is going to ruin your hearing.

canklecat

Why settle for a mere car or train horn when you can get the Brown Noise?

PdalPowr

If only it could be so.