I’m not judging – honestly – I am an ‘All of the gear, all of the time’ person, and so MY opinion is that cyclists SHOULD wear a helmet – I do on my mountain bike, and I won’t let the kids play on their bikes without a helmet – I’d say that if you’re gonna mix it up on busy rush hours roads in the city, you really should wear a helmet – although I do accept that everyone has the right to make that choice for themselves.