The streets of Paris are full of bicycle commuters,
and one sees many of the rental bikes (Vélibs) utilized.
They come equipped with a lock, an ample basket,
easily adjustable seat, three gears, hand brakes, and...
With a Navigo pass, a simple swipe of the card and you are good to go.
For a tourist, there are a few more steps,
but still easy and inexpensive when you understand how it is charged.
How do I know?
Vélib on Rue de Vaugirard