The formative experiences of Argentinian Ernesto “Che” Guevara, later icon of the Cuban revolution and martyr to the Marxist cause, during a trip through South America in 1952 are the subject of this energetic, if rather meandering, film by Brazilian director Walter Salles. The fundamental thrust of “The Motorcycle Diaries,” based on Guevara’s own memoir and the book by Alberto Granado, his companion on the journey, is that the 23-year old man’s encounter with social injustice and human misery during that eight-month odyssey was the catalyst in the radicalization of his social and political views. That’s a perfectly sound, historically persuasive argument; if there’s a problem with the way that Salles, screenwriter Jose Rivera and star Gail Garcia Bernal present it, it’s that–perhaps inevitably–Guevara is made to appear so sensitive and honest that he comes perilously close to a kind of secular sainthood. (Even his asthma gives his suffering greater weight, as does a subplot about his abandonment by the fiancé whose family finds him unworthy of their daughter.) There’s a hagiographic tinge to the film that some will find very hard to take.

Nonetheless, there’s plenty to praise about “The Motorcycle Diaries.” Salles is an elegant filmmaker, even when he’s going for a gritty sense of almost hyperbolic realism, as is the case here. His picture looks quite beautiful, making excellent use of sometimes breathtaking locations, and one can see a master craftsman’s hand in every frame–although he eschews the radiantly poetic ambiance of his last film, “Beyond the Sun,” preferring instead the equally careful but less ostentatious style of 1998’s “Central Station.” (Eric Gautier was the cinematographer, and working in Super 16mm with a good deal of hand-held camerawork, he avoids the jittery, often unattractive visuals that sort of approach so often results in. The production design by Carlos Conti is also effective in evoking the period.) The director is further blessed with a star in Bernal who might be almost impossibly handsome, but manages to remain more boyishly charming than irritatingly smug in Guevara’s principled earnestness; his rather immature intensity keeps the film from spinning off into the polemical political point-making that could easily have been its undoing. (The point is made amusingly on several occasions when Guevara is unable to shade the truth with people, even though a little white lie might be beneficial to the travelers.) Salles and Bernal can’t conceal the essentially episodic nature of the picture, nor can they fully sustain the sequences where the socio-political subtext is heaviest (one involving a native couple, thrown off their land, who are searching for dangerous work in a mine), or the rather heavy-handed message conveyed by Ernesto’s final swim across the river separating a leper colony from the staff quarters. But their collaboration is ordinarily so skillful that you may find yourself moved, whatever political views you bring with you into the auditorium.

Unfortunately, they can’t do much to mitigate the busy, frenetic performance of Rodrigo de la Serna as Granado. He was clearly instructed to play the mildly obtuse everyman to Bernal’s more sophisticated observer, but as written the character is made into a near-caricature of the earthy, chattering best friend, and De la Serna ignores no opportunity to play up his showily down-to-earth quality. There’s also too much business having to do with the broken-down cycle on which the duo begin their journey–one too many spills, or the crocodile tears that Granado sheds ober it when it breaks down. The remainder of the cast is capable, but this is essentially a two-hander, and De la Serna doesn’t quite keep up his end.

“The Motorcycle Diaries” ends with Guevara’s sudden decision to fly off to Cuba after his long tour ends in Venezuela, using a series of captions to inform the audience of the salient points in his later career and adding brief footage of the real Granado, wizened with age (he later went to Cuba and served as a doctor under the new regime) over the end credits. It reminds one that the film provides us with only the initial act of a much longer story, one that–if continued accurately–might not prove quite so simplistically uplifting. (And if you want to continue the biography cinematically, your only recourse is Richard Fleischer’s 1969 atrocity “Che!” in which Omar Sharif, of all people, plays the title role and, even more absurdly, Jack Palance is Castro. That route is definitely not recommended.) But though it doesn’t tell the whole story, Salles’ portrait of the revolutionary as a young man is sufficiently strong to hold the attention.