# Mechanics of Pedaling a Bicycle While Standing

Dante Brown, “Mechanics of Pedaling a Bicycle While Standing”
Mentor: Andrew Dressel, Mechanical Engineering

The purpose of this analysis is to use a simple mathematical model to rationalize why cyclist rock the bicycle when pedaling while standing. To begin the research, a broad literature search was performed. The topics ranged from kinematics and the biology of sprinting to changes in aerodynamic drag. However, no papers were found that directly relate to this research. This allowed for the ease of incorporating new variables when necessary. Measurements were taken from a standard road bicycle. From these measurements and assumed values of forces, mechanical work was calculated for the forces of one leg without tilt, two arms with tilt, then both combined with tilt. This was done to graph the change in work. The first set of calculated values was the work done by one leg without bicycle tilt. This set of values is the baseline for comparison. The second set is the work done by one leg with bicycle tilt. This showed a steady decline until a minimum at 15° where it reached 97.06% of the work done with one leg without tilt. The final set was the work done by one leg with two arms and tilt. This was the set that will give the necessary conclusions. This set showed a maximum at 5° where it reached 100.2% of the work done by one leg without tilt. With the current mathematical model, the work gained by using both arms with tilt is minimal. The current mathematical model is sensitive to the measured values, as well as the relative force from the arms and legs. However, when the finish of a stage comes down to inches, every percentage that can be gained will be.