A method of biomechanical analysis of the posture of a user, and of automatic customized manufacture of bicycle parts, comprising the steps of: a) determining a matrix of optimal angular ranges ( β REF) between body segments of a general user at his/her joints from standard tables; b) collecting historical data ( D A) of the user and converting it into numeric strings; c) performing a functional morphological analysis of the user by detecting measurements of the body segments of the user by means of a 3D scanner; d) analyzing dysmetria and postural defects of the user using initial pressure data ( D W) detected in the standing and bent positions by a platform; e) providing a computer with software installed therein for processing said optimal angular ranges ( β REF), said numeric strings of historical data ( D A) and said pressure data ( D W) to determine initial data ( D IN) concerning the main parts of the bicycle; f) providing pressure sensors associated with insoles designed to be inserted into the shoes of the user and a pedaling simulator assisted by said computer, having additional pressure sensors in the saddle and the handlebar and actuators for automatically changing the optimized three-dimensional position of the saddle and the handlebar according to said initial data ( D IN); g) detecting instantaneous pressure data ( D W) using said sensors ( 28, 29) and current angles ( β) of body segments using said 3D scanner during a dynamic test of the user on said simulator by setting a standard pedaling resistance thereon, according to the heartbeat rate, to obtain instantaneous data ( D IS); h) comparing said instantaneous data ( D IS) with said initial data ( D IN) by said computer to obtain optimized final data ( D OUT) of the bicycle, to be transmitted to said simulator for automatic adaptation of the position of the saddle and for configuration of the shapes and sizes of the frame and the pedal cranks; i) providing a holographic spatial representation of the image of the user on the simulator and the optimized configuration of the bicycle by a 3D holographic projector controlled by said computer, to check proper positioning of the user and make any correction to the configuration; j) transmitting said optimized final data ( D OUT) to one or more 3D printers for manufacture of the basic parts of the bicycle using this three-dimensional technology or, alternatively, for computerized selection of existing parts in stock in warehouses and stores from databases. a) determining a matrix of optimal angular ranges ( β REF) between body segments of a general user at his/her joints from standard tables; b) collecting historical data ( D A) of the user and converting it into numeric strings; c) performing a functional morphological analysis of the user by detecting measurements of the body segments of the user by means of a 3D scanner; d) analyzing dysmetria and postural defects of the user using initial pressure data ( D W) detected in the standing and bent positions by a platform; e) providing a computer with software installed therein for processing said optimal angular ranges ( β REF), said numeric strings of historical data ( D A) and said pressure data ( D W) to determine initial data ( D IN) concerning the main parts of the bicycle; f) providing pressure sensors associated with insoles designed to be inserted into the shoes of the user and a pedaling simulator assisted by said computer, having additional pressure sensors in the saddle and the handlebar and actuators for automatically changing the optimized three-dimensional position of the saddle and the handlebar according to said initial data ( D IN); g) detecting instantaneous pressure data ( D W) using said sensors ( 28, 29) and current angles ( β) of body segments using said 3D scanner during a dynamic test of the user on said simulator by setting a standard pedaling resistance thereon, according to the heartbeat rate, to obtain instantaneous data ( D IS); h) comparing said instantaneous data ( D IS) with said initial data ( D IN) by said computer to obtain optimized final data ( D OUT) of the bicycle, to be transmitted to said simulator for automatic adaptation of the position of the saddle and for configuration of the shapes and sizes of the frame and the pedal cranks; i) providing a holographic spatial representation of the image of the user on the simulator and the optimized configuration of the bicycle by a 3D holographic projector controlled by said computer, to check proper positioning of the user and make any correction to the configuration; j) transmitting said optimized final data ( D OUT) to one or more 3D printers for manufacture of the basic parts of the bicycle using this three-dimensional technology or, alternatively, for computerized selection of existing parts in stock in warehouses and stores from databases.