Evaluation of four-bar mechanisms for bicycle pedals

As the Global Warming destroys gradually the life on the earth, vehicles driven by clean energy are of importance. Therefore, in this paper, mechanisms for bicycle drivetrain are scrutinized starting from its initial invention to attract attentions of the people in the field of mechanism. Some recent health problems caused by design of modern bicycles are highlighted. Optional several mechanisms such as crank rocker, double crank, double rocker, slider crank, and inverted slider crank for the drivetrain of bicycle are evaluated. Each of them was assessed in the perspective of applicability by using shelf-ready products. A double-rocker mechanism is schematically designed by using GeoGebra. An analysis for the geometric constraints of the design and torque are presented. Finally, the double rocker was concluded to design a pedal drivetrain. An optimization was carried out by using Microsoft Excel. The optimal dimensions were delivered. The maximum torque 90 Nm. The maximum energy can be produced is 600W.