Talk:Exercise bike

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Client comments on the Mechanical Analysis

This mechanical analysis focuses on the moment of inertia of heavy metal wheel and braking friction, which are critial to the design of the exercise bike. Here is my comments about the analysis:

• The calculation for the flywheel rotating speed change by brake seems not correct: 28.27J=1/2*0.646*^ω2. So ω=9.35 rad/sec = 89.3 rpm. Please verify your calculation.
• According to energy conservation, the energy input by a biker pedaling should be equal to the friction energy plus the residual energy going into flywheel. For example, assuming a biker operates the exercise bike and maintains the flywheel rotating at a constant angular speed 180 rpm with brake applied, then the energy consumption by the brake per second is E_B = 28.3J, and the energy going into the flywheel per second is E_W = 1/2*I*ω² = 0.5*0.646*(180rpm*2π/60)² = 114.7J. So the total energy needs to provided by the biker is E_B+E_W = 114.7+28.3 = 143J.
• It is suggested to add a figure of flywheel rpm versus calorie consumption can be added into the analysis results. It will be useful information to the exercise bike users.
• The moment of inertia of the lighter flywheel is not given in the analysis. Please double check this.