The key part of a bicycle, to which wheels and other parts are fitted, is a bicycle structure. Based on the safety bike, the current and most common frame configuration for an upright bicycle consists of two triangles: a main triangle and a paired rear triangle. This is known as the diamond frame.
The bicycle’s main structural component is typically made of steel, aluminum, titanium, or carbon fiber. Comprising a top tube, head tube, down tube, shell of the bottom bracket, bench tube, seat stays, and stays of the chain (see image). A frame and fork marketed as a blend is known as a frameset.