In the last 40 years can you remember an adult lead character choosing to ride a bike as a form of transportation in an American movie or tv series?
If a minor character has a bike and uses it for transportation - it’s clear they would like a car but for whatever reason they don’t have one. Another character might say to them “Why don’t you have a car?” and their reply will be something like “Don’t ask.”
Last night I watched “Flashdance (1983)”. Jennifer Beals plays an 18 year-old who lives on her own and she doesn’t have a car. She uses a bike instead.
Probably not the kind of example you’re looking for but my first thought was “Premium Rush”.
My recall of the movie isn’t great but it’s about bike messengers, so main character and others choosing to ride bikes to get places fast