noglider 

I just moved to Manhattan, where everyone moves about as if it's the Wild West. I'm thinking of getting a loud horn. The Airzounds is one I'm considering. Anything else?

ItsJustMe

Nothing else that I've seen beats the airzound. The downside is that it generally doesn't work below about 35 degrees F. When I tried to use it that low it messed it up and it wouldn't work after it got warm either.

I took the back off, flattened the diaphragm, flipped it around the other way and it works again now. But still not in the cold. It'd be nice to find a diaphragm material that didn't mind the cold.

Other than that, they're all electronic and effectiveness is up for debate. The reviewers that love them seem to all say "I set this off inside and it was deafening." Yes, but inside and outside are COMPLETELY different things. Also electronic trills do not put fear into a motorist's heart like an air horn does.

The Hornit seems to be about the best.
https://www.amazon.com/dp/B006TDEV20

Or the Megahorn.
https://www.amazon.com/dp/B004IY7IJU

Both have people that like them.

noglider 

Thanks! Clearly, nothing is perfect, but from the reviews, it seems that Airzound is best.

cplager

I have an Airzound and a Hornit. I think the Airzound is slightly louder, but it always seems to need to be recharged (which is only pumping it up). The Hornit has two different sounds you can choose and runs on batteries. I now use the Hornit (it's just always there when I need it).

noglider 

Honestly, the airzound sounds more convenient. I have a pump more often than I have spare batteries, and as a bonus, air is less toxic than the stuff in batteries.

ItsJustMe

I don't know how much I'd have to use an Airzound to use it up very much. I pump mine up about once a year. I probably don't blow it more than 10 seconds a year. Depends on where you live I guess.

Shahmatt

I commute daily and have the airzound. I think it's very effective. I just top up air weekly along with my tyres.

StarDust4Ever

Can't remember the brand but I had an air horn at one time. You pump it up to 80psi. Unfortunately, once the adrenaline gets pumping, with my adult ADHD, I tend to get obnoxious. I kept tooting the horn whilst genrally being a nuisance on the walking paths on my college campus. People jumping up 4 feet in the air, sometimes spilling their books! The air horn did not last long before whimping out. Also the cable eventually got severed and stopped holding air. I still have it somewhere and could easily patch it up again.

Bottom line, if you're the kind of person to get some cool bling like a super loud horn andl want to show it off every chance you get, with ten seconds of air time, it won't last very long.

Also, the bottles were basically made like an 8 ounces or so plastic soda bottle, probably to appease the 'weenies who would likely have no use for such a frivolous device. If the cable could be lengthened and retrofitted onto a larger bottle, like say a longer cable to a 2-liter coke bottle on the back rack, it would last a lot longer. I wonder if a 2 liter bottle could withstand 80psi though.

2_i 

There is is this DX bike horn, working off a manually operated pump. Off the bike it sounds pretty loud, but its mounting hardware is pretty lousy. I've got one but never got around to mount it.

In everyday life I use a DC moped horn powered from 5 rechargeable AA batteries. In my case, the batteries are charged by the hub dynamo but the two do not need to be connected.

ItsJustMe

Yes. 2L bottles burst at around 150 to 180 PSI. Protip: wear hearing protection when testing this, assuming that, like me, you pump up a bottle right next to you with a bike pump. Ow.

noglider 

I wouldn't use a loud horn in a quiet setting. I'm doing battle on the mean streets of Noo Yawk Ciddy. Ya gotta be loud to be hoyd, knowamean? I'd use a bell in situations that aren't super urgent. I already have a bell on every one of my (too many) bikes. The horn is for when someone is cutting me off and will soon kill me if he doesn't stop right now.

I will occasionally use it for pedestrians who blithely saunter in the bike lane, possibly with headphones on. They need to be told off, and this is the best way to do that. I've already yelled at them and had a screaming, roaring tantrum. I wrote of that story some time ago.

StarDust4Ever

The bigger problem is not if the bottle can withstand the pressure, but if I can jury rig something into the bottle cap. The hose is too flimsy IMO and I have no idea if I can make a homemade adapter that will hold up if I attempt to connect it to a larger bottle. Even a small 20oz soda bottle would more than double the range on the horn.

I now use a bell exclusively on my bike for riding the MUPs.

I'll be the first to admit it: I was being a [insert expletive here] that day. I have a theory about why some cyclists (including myself) make irrational decisions while biking: When you excercize, your body releases endorphins which give you a natural high. Taking uncessesary risks increases this euphoric effect. The natrual high is why I feel cycling can get so addictive compared to working out in a home or gym. Secondly, your heart rate goes up as your body releases adrenaline, which is a similar thing that happens when a person feels threatened and initiates a "fight or flight" reaction. This explains the irrational road rage many cyclists exhibit. People are literally riding "high", except it's caused by naturally occurring endorphins and adrenaline rather than foreign substances. Then you cool down and think (or not) about how reckless you were, then you're like "that felt awesome" and get on their bike again. I swear I'm normally a responsible 32 year old adult, but whenever I'm on my bike, I'm a bratty teenager half my age.

noglider 

I think I get where you're coming from. I might have made some similar things when I was your age. I'm 52, and if I had those impulses, they're pretty much gone now. Life does that to us.

ItsJustMe

I think that the Airzound uses a standard bottle cap screwed to the top of their bottle. You should be able to find a matching 2L bottle.

Z R I D E R

I have a Hornit, it's so loud and I've used it with great success many times. It really helps me when drivers are turning into my lane and can't necessarily see me due to obstructions (like parked cars, trees, etc.). I really like that I don't have to worry about pumping anything up (runs on batteries) and it has a trigger that can be placed wherever is most convenient for your finger to push it.

Downside: the louder of the two sounds that it produces is unrecognizable to most people, unlike the airzound which clearly sounds like a horn. The Hornit just sounds like a crazy loud and fast siren, and not everyone will react to it in a way that you want or react to it at all. However, I've had way more successes than failures with it so far.

Z R I D E R

I could be wrong, but this problem has more to do with physics than it does the diaphragm material. As the temperature outside decreases, the temperature of the air inside the bottle will also decrease which decreases the pressure that was built up inside. The atmospheric pressure also plays a role in the problem.

cplager

I agree with this. I like the sound of the AirZound much better, but I like the reliability of the Hornit. I'm using the Hornit now.

PV=nRT for an ideal gas (for which air is not, but..)

P is pressure and T is absolute temperature. 32F is 0 C is 273 Kelvin. 25C is 77F is 298 Kelvin. So this suggests that pressure should drop 10% over this temperature range. But the effect seems a lot worse than that. So I think it is the diaphragm reacting to the cold (or maybe water droplets freezing on the diaphragm???) more than the lack of pressure (particularly since it doesn't seem to have a problem just over freezing, but gets bad quickly).

ItsJustMe

It's not pressure. Even if you pump it back up, it still wont' blow, it just hisses.

demoncyclist

I had an Airzound, but it wasn't a convenient solution for me, and there was no good mounting spot on my wife's bike either. We both have Hornits now- they are mounted side by side with our headlights on Topeak Bar extenders that mount under the handlebar. The button is conveniently tucked just below the brake lever, so it can be reached from tops, drops or hoods.

bikepro

Have a look at this. https://www.amazon.com/Hornit-dB140-C.../dp/B006TDEV20

zebede

I really like the concept of the Airzound and wanted to put one on my commuter bike. Unfortunately it will not fit on drop handle bar diameter. Its designed for Mountain Bike handle bar diameter.

ItsJustMe

The Hornit has already been mentioned several times in this thread, in fact that URL has been posted already on this page.

anthonybkny

the hornit's sounds arent recognized and are generally ignored around here. my buddy has one and people pretty much ignore it, but i do fine with a brass incredibell. if youre worried about cars, yell or bang on the window.

01 CAt Man Do

Coming from someone from NY this doesn't surprise me. Lots of distractions in NY. I doubt everyone ignores the horn though. Speaking for myself if I heard a strange loud noise while driving I think I might glance in the general direction of where I thought the noise was coming from.

For me another important issue in deciding which horn to buy is "foot print". The smaller the better. Unfortunately smaller doesn't usually translate over to "louder". Still all things considered the "Hornit" sounds like it could be a good compromise and be easier to work with. I might buy one just to screw around with but rarely do I find myself needing a horn. Than again if I ever decide to commute by bike to work or do a planned ride through a city environment I would love to have a horn. More added geek factor but I can deal with that.

ItsJustMe

I think that is the problem with things like the Hornit. It makes people "glance in the general direction."

What you want is what the Airzound does, which is to make people reflexively go "OH S41T!" and jam on the brakes, THEN look to see what's going on.