Athens could be an ideal bike city. The weather and the landscape contribute to that. The truth is that, so far is not very bike friendly, but a growing group of athenians is trying to make it one.
My favorite rides around the city are around the city center and along the beachside. If you want to try one of those rides in Athens, visit Funky Bike. The store opened on October 2010 by Takis & Christoforos and here you can rent a city bike for a day or more.
Located very close to the Acropolis metro station, Funky Bike is the first stop of your a beautiful ride down Dionysiou Aeropagitou, around Plaka and Anafiotika. You can also rent your Funky Bike on a Friday afternoon and join the Freedayers night-ride around Athens.
In Funky Bike you will also find, except bicycles, bike accessories, t-shirts and artwork, of course always bike related- just look at the lamps that hang outside and the one inside the store.
Last but not least: the opening hours are kind of fixed, meaning that it is possible to arrange returning your bike some (reasonable) time after the official closing hours.
Enjoy the (funky!) ride!