Okay, okay. Unless you're a serious cyclist who travels with his own custom-made helmet - or an adventurous traveler with some local friends - you're probably not going to be joining the nighttime Masa Critica group bike ride through Buenos Aires' streets, as pictured above. (Though it's not impossible - check out www.masacriticabsas.com.ar for details.)
That doesn't mean you can't explore the city on two wheels. Thanks to an ever-expanding network of bike paths and a relatively new urban bike-share system, cycling through Buenos Aires is more accessible than ever. But unless you know your way around already, it's best to start off with a guide.
Biking Buenos Aires is one of several reputable agencies offering full- and half-day tours plus specialized options, like the Parks & Plazas tour, or the Sunday afternoon architecture tour. Not to mention that they offer the holy grail of Buenos Aires bike tours - the Sunday street art bike tour, organized in collaboration with Graffitimundo.