I might have problems selling the style of brothers Jean-Pierre and Luc Dardenne to someone who has never seen one of their films. The Belgians usually avoid working with big stars, glamorous locations or lush orchestrations. Their themes are poverty, unemployment and the everyday struggles of people on the margins. But Cannes Juries love them — Rosetta and The Child are both past winners of the coveted Palme d’Or. Their 2011 Grand Prix winner, The Kid with a Bike (Le Gamin au Vélo), is another brilliant example of no-frills film-making that grabs you from the shot and makes you care.

That title is reminiscent of Vittorio De Sica’s Bicycle Thieves (1948), but here 11-year-old Cyril (Thomas Doret) has lost both his dad and his beloved vélo. (There’s no sign of mum, either, but this is never explained.) We learn that Guy (Jérémie Renier) has no intention of retrieving his son from the children’s home and – even worse — the bike has been sold to make some quick cash. But Cyril’s desperate quest does yield one huge slice of luck, when he (literally) runs into hairdresser Samantha (Cécile De France), who buys the bicycle and agrees to foster him at weekends.

The Dardennes’ preference for close framing takes us straight into Cyril’s crisis-hit world and keeps us there throughout the 90 minutes. This, combined with the breakneck pace of the film, reflects the urgency of how the boy deals with his problems. For the first 20 minutes it feels as though we’re being dragged from one nondescript to location to another, as Cyril runs, cycles and scales walls. Like him, we’re barely aware of the surroundings or of the adults peripherally involved in his drama.

In his first movie, the blonde and rather melancholy Doret plays Cyril as an appealing mixture of naiveté and guile. He has no trouble escaping from the children’s home or getting into his father’s apartment block with a lie about a doctor’s appointment. But the bicycle seems to be a magnet for trouble and, combined with his tendency to put his trust in the wrong people, leads him into further scrapes. It’s the awkward relationship between the rootless and troubled Cyril and his new guardian Samantha that provides the emotional heart of this film.

Cécile De France (Mesrine: Killer Instinct, The Singer) brings a star quality that’s perhaps unexpected in the low-budget world of a Dardenne brothers film. We never learn much about Samantha’s backstory or personal life, apart from her willingness to put this boy’s welfare before her boyfriend’s wishes. Like Cyril, we just have to take her at face value. De France brings great warmth and an understanding of the hard choices involved in being a parent – even when you’re not one. Samantha is never aggressive but she won’t be pushed around either, as when she forces Guy to face up to a difficult conversation with Cyril.

In The Child (2005), Jérémie Renier played the feckless young father who sells his own baby. His character here is older, but hardly a model of responsible parenthood. Why does his new life leave no room for his son? In the short scene where Cyril finally tracks him down, the pair are shown stirring pans in a restaurant kitchen. But the domesticity is a cruel illusion: Guy is just granting him a few minutes before trying to banish him from his life.

One of the reasons I liked this film so much is that there weren’t any overt political messages or cartoon villains. We don’t see much of the children’s home or the people who run it, but it doesn’t appear to be a model of Dickensian cruelty and neglect. Cyril’s life is hard because he’s just a boy with no control over how adults behave. He looks for a male role model but his trust is abused by his father and – most shockingly – by local drug-dealer Wes (Egon Di Mateo). I found it sad but completely convincing that Wes could lure Cyril into a criminal act, with soft drinks, video games and flattery. Meanwhile, the stoic Samantha appears willing to sacrifice just about anything to help Cyril but meets with distrust, lies and even an outburst of violence.

There aren’t many laughs in The Kid with a Bike but, thankfully, it’s not awash with sentimentality either. With well-judged performances and brief but effective bursts of music, the Dardenne brothers bring light into Cyril’s world and the hope that things might turn out well for him.

The Kid with a Bike is released in selected UK cinemas on Friday 23 March.

(Review first published as part of Sound on Sight’s coverage of the 55th BFI London Film Festival.)