The last friday of each month, you have critical mass!
But what is that? Well, I cant explain it better than Wikipedia: https://en.wikipedia.org/wiki/Critical_Mass_(cycling).
In short, the goal is to be enough bicycles on the streets so that you can drive safely. It is not a demonstration.
In Zürich, this works very well, with around a thousand people everytime, and even more on warm, sunny months. In june 2021, the number of people rose up to 10’000!
Another fun thig that you will see at the critical mass are the so-called “wäggeli” – basically DJs on a bike! There is also a mobile karaoke and a mobile photobooth. You can do anything on your bike!
Isn’t it dangerous?
Not really, the critical mass is not a demonstration, it is traffic. They drive slowly and you are portected by the mass. Some car drivers may get annoyed and honk at you, or try to go through the mass. It won’t work – so keep your calm.
You won’t get arrested either. Just respect the traffic rules and do as the police tells you to. (or not 😉)