The introductory part of the paper is based on the history of emergence of important inventions which became a turning point and because of which the world started making progress. The appearance of the wheel, its development and improvements throughout the years are described. The concept of friction and the way it affects the wheel during its movement and stopping. The construction of the bicycle which resulted from the need of the inventor and improvements by others which led the invention to look the way it does now. The gradual development of gears and transmission systems are also described. The second part defines ergonomics as an important scientific discipline, its classification and the principles on which it is based. The influence of the ergonomic design on the human body and adjustment in accordance with kinematic principles and the limitations of humans is explained. The importance of achieving comfort and proper design of bicycles and their components is demonstrated. The reduction of strain by bringing the body into a proper position and the improvement of performance is observed. The experimental part of the influence of the construction of components on the properties of riding is demonstrated. The third part provides an overview of the factors affecting the stability of the bicycle, the impact of the force of friction during a bicycle ride and distinctive forces during riding over a surface with or without inclination. An analysis of 4 types of surfaces and their impact on the quality of riding is given, as well as their correlation with the rolling resistance coefficient. The basic ways of changing gears, as well as the features of the outer and inner power structure are described. The efficacy of the bicycle is defined, as well as its advantages and disadvantages. The basic types of bicycles and their main features are listed. Specially designed bicycles and the latest kind of electric bicycles and their functioning principles are included. Nine steps to help any amateur choose the right bicycle are listed. All the components of the bicycle and their features, materials, production and other things are explained. Additional equipment for the bicycle and the cyclist to facilitate and improve riding is added. The final part provides a description of the functioning principle of a 3- gear power transmission system in the back wheel hub of the bicycle including a planetary transmission system. The basic components of the structure and their functioning principle are described. The structure has been calculated and generated in the SolidWorks19 programme with the necessary figures. According to the ergonomic principle a bicycle has been designed with the same power structure of the planetary transmission system, with the purpose of achieving a beautiful, simple, effective and special design.