These days our family cycles a lot for commuting. It’s really easy to observe that people in vehicles treat us far better if we look like humans, wearing normal street clothes, rather than wearing high-viz or, far worse, cycling gear.
The bike bell is for polite notice, not alarming. The best alarm system you have is your voice, which is variable volume and tone. For ultimate effect slap the panels of cars, as it is very loud inside the vehicle.
Most of them were extremely apologetic or even shocked (as if I appeared from thin air). None of them were angry for scratching their door. Some people are just lost in thought it seems...
A unexpected loud noise recently caused me to get tinnitus and hyperacusis, and trust me, you don't want either of them!
You know a diagnose is bad when Wikipedia lists suicidal thoughts as a common side effect....
People have used drills+pumps to drive similar hand-held horns at football games so it is doable.
[1] - https://www.youtube.com/watch?v=NOKgg5iCw_c
[2] - https://www.youtube.com/watch?v=enF0m6J7g2w [Tiny car with train horn]
https://www.tacomaworld.com/threads/are-you-tired-of-your-wi...
https://www.hpvelotechnik.com/en/recumbent-trikes-bikes/acce...
It is loud.
Having personally blown up beverage bottles by overpressurizing them (be very very careful doing this!), when they go, they go violently.
*We had a valve on the air line so we could be at a safe distance when pressurizing. Be very careful. It's unpredictable exactly at which point they'll blow. Sometimes they hold full pressure for a couple seconds and then go.*
IIRC these came out in the early-mid 90s; a bike messenger trick at the time was to fasten the horn to your handlebars with velcro, so you could take it off and hold it near a car window when triggering it.
That's a huge assumption, and likely incorrect.
Here I thought my 4.5 mile (7.25 km) bike commute was a bit long...
The winters were rough though.
So I am using LiPo 3S, 2200mAh. Works like a charm. I keep it at its storage voltage (3.7-3.8v per cell), and it hardly drained the battery (there is no paracitic drain). Whole thing was like $20.
https://people.kernel.org/bleung/how-to-design-a-proper-usb-...
More info: https://hackaday.com/2023/02/07/all-about-usb-c-manufacturer...
Putting an aerosol fog horn (available from boating supply shops) in the bikes water bottle holder is much simpler, louder and more effective.
Needs like 18 amps if that tells you anything.
Generally in those situations I shout really loudly at the driver, and in general they seem to hear me
Agreed. I had a supercharged V8 Jaguar that I could barely hear.
And my Audi has a system that actually pumps engine noise into the cabin, so you can hear that, but not the outside world.
The Fire Department I was at was looking at "thumpers" - augmentations to sirens that make cars in front of them vibrate (a la those people playing too much bass too loud).
Not just sound proofing, but inattentiveness. I've been behind people on semi-rural quiet roads with my 40,000lb fire engine behind them, lights, sirens, and airhorns, and they've driven for a mile or two completely oblivious.