Although the physics of cycling itself is a complex mixture of aerodynamics, physiology, mechanics,
and heuristics, using cycling as a context for teaching physics has a tradition of certainly more
than 30 years. Here, a possible feature is the discussion of the noticeable resistant forces such as
aerodynamic drag and the associated power consumption of cycling. We use an energy-based approach to
model the power input for driving a bike at a constant speed. This approach uses a numerical
simulation of the slowing down of a bike moving without pedaling which is implementable with
standard spreadsheet software. The simulation can be compared directly to simple measurements with
real bikes as well as to an analytic solution of the underlying differential equation. It is
possible to derive realistic values for the aerodynamic drag coefficient ##IMG##
[http://ej.iop.org/images/0031-9120/51/1/015001/pedaa054dieqn001.gif] {${{c}_{text{D}}}$} and the
total power …