Car horn silencer for bicycle

thingiverse

I needed a loud horn for my bicycle for obvious road security reasons. So I used a very loud car horn, a 12v 7.2Ah SLA (sealed lead-acid) battery, and a handlebar push button. It was a bit too loud for city use (112 dB) so I wanted to tone it down. I made slide-on silencing plates. The plain one silences it down to about 88 dB, albeit with a bit of rattling caused by the sound waves not being able to escape the horn easily. My preferred one is the one with a small slit at the end. It reduces the output to around 94 dB, with a much cleaner sound. I tried with wider slits but it did not make a significant change to the sound compared with nothing on it. The plain one can also be used to protect the opening of the horn on dirtier roads or gravel bike paths. Print time is about 1h10 for a single silencer. The fit is absolutely perfect on my horn, with a happy accident click in place at the end.