The cops don't look twice at me anymore. I think it may be age-related. I hear about young people getting hassled by the cops all the time. If you look to be low-30s or less, watch out. If you look well over 40 you're OK.
Look odd, like the only dude on a bicycle and you attract more attention. It doesn't make sense because the criminals are trying to blend in. But you can't pay a lot of attention to everybody because that's not practical. So the police keep busy to feel like they're doing something important.