a great option when available is also the surf bus, a special private bus taking visitors from zona sul to all the main surf beaches in rio, including barra beach.

the surf bus leaves from largo do machado every day at 7 am, 10 am,1 pm, and 4 pm.  more details are posted on their webpage.           

getting to barra beach via public transportation can be difficult, since normally buses do not connect directly the beaches of zona sul with barra beach, as they run along the main avenue in the neighborhood, which is not close to the shore.