OUR guide arrives at a jog, blue toenails in bronze sandals. There's four hours of riding ahead, but I briefly regret my sensible sneakers.
We're here for the art, not the exercise - and in image-conscious Buenos Aires appearance is everything.
Melissa is a sweet and drawling east-coast American, transplanted in Argentina with the help of a romance.
Once in BA, she fell in love again - with the city's exploding street art scene.
She's part of Graffiti Mundo, a BA-based group working with local artists to run street art tours.
Our two-wheeled excursion coincides with an event dubbed "The Meeting of Styles" - an international graffiti collaboration that sees sponsors provide paint, and local supporters provide space.
Not that there's ever a shortage - the sprawling Argentine capital is bigger than London, and many walls are considered public property.
Argentina's political graffiti began in the 1950s. (When divisive national icon Evia "Evita" Peron died of cancer in 1952, we're told "viva cancer" was scrawled across the city.)
Melissa says tradition has probably been a saving grace for modern-day graffiti artists. "All the political parties rely on graffiti to get their message out - so none of them would risk trying to ban it," she says.
For the most part, the artists keep out of politics. Inspired during Argentina's economic crisis in 2001, the new graffiti isn't as much activist as distractionist. As we roll through hip Palermo's grids of coffee shops, rooftop bars and designer stores, there's thousands of works, bright faces and figures, fantasy scenes and statements.
Inevitably, art melds with advertising - one of the city's most exclusive restaurants hides behind a façade of stencil graffiti. There's even a bar dedicated to the form. "It's Buenos Aires first stencil bar - and its only one," Melissa explains.
Wheeling round a corner we see our first piece in progress. The broad daylight perpetrators look happily at home.
Four paint-splashed lads survey two huge heads; a weekend of work that's emptied dozens of paint cans. Nearby perfectly-formed bodies twist into each other, in a gigantic Renaissance frieze to rival the Masters. But each male form has an animal head, and they're all wrestling for a football.
It's one of a series by local lad Jaz, all sly comments on the hooligan culture in Argentine sport.
Another few streets and we're weaving through crowds of blue and yellow, as they pour into a looming soccer stadium (Estadio Don Leon Kolbovski). We roll on, passing a burnt-out truck, then a bus in the same condition. Melissa doesn't blink, and when I ask she just laughs.
"That's been there for months - I guess it's what Jaz is talking about." Splashing some paint on a wall suddenly seems a particularly law-abiding pastime.
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