Teenage BMX riders Goose (James Lugton) and PJ (Angelo D’Angelo) become friends with Judy (15-year-old Nicole Kidman in one of her first major roles), who is working the summer at a supermarket when their bikes are destroyed by runaway shopping trolleys.
Judy is fired and, with time on their hands and in dire need of money, the three friends decide to go fishing.
Discovering a sunken treasure of illegal police-wavelength walkie-talkies gives the friends a money-making idea.
It also sets them on a collision course with some incompetent but persistent bank-robber goons and an equally ineffectual police force.
Judy is eventually captured by the crooks and the other two are helpless to save her unless they can enlist the help of every BMX-er in town.
Capitalising on the BMX bike craze of the 1980s, the film tells a simplistic story of adventurous teenage goodies versus bumbling adult baddies.
The thinly-plotted premise provides an opportunity to showcase plenty of bike stunts amidst extended comic and cartoon-like chase sequences around Sydney. These include a chase through Warringah Mall and a famous scene shot with BMX bikes inside the Manly Waterworks.