Video narration
Imagine opening a flat-pack box: a pile of separate pieces, not yet something you can use. A bike starts in a similar way. A frame begins with material shaped and joined into the structure that holds the bike together. But the frame is only the start. Wheels, brakes, gears, and handlebars are made separately; some come from other makers, then are brought to the place where the bike is assembled. There, workers fit the wheels to the frame, connect the brakes and gears, and add the handlebars and other controls. Each part has to work with the others: a wheel must spin freely, while the brakes need to slow it when you squeeze them. Before it's ready to ride, the assembled bike is checked: wheels turn freely, brakes work, and parts are secure. That's the path: build the frame, fit the working parts, and check the whole bike for a safe ride.