A dynamic system model of an off-road cyclist

Area of Science:

• Biomechanics
• Mechanical Engineering
• Sports Technology

Background:

• Optimizing off-road bicycle suspension requires a dynamic model of the bicycle/rider system.
• Previous models have not fully captured the complex dynamics of the cyclist component.

Purpose of the Study:

• To develop a dynamic system model of the cyclist for bicycle suspension optimization.
• To determine the transfer functions of the arms and legs through vibrational testing.
• To validate the model by comparing simulation results with experimental data.

Main Methods:

• Conducted four random-input vibrational tests on seven experienced off-road cyclists.
• Determined experimental transfer functions for the arms and legs.
• Developed a lumped parameter system model including visceral mass, arms, and legs to replicate resonance peaks.
• Computed frequency responses and optimized stiffness and damping parameters via simulation.

Main Results:

• The developed cyclist model successfully reproduced essential features, such as resonance peaks, of the experimental transfer functions.
• Good agreement was found between the simulation results and the experimental data across all tests.
• Optimal stiffness and damping parameters were identified for each individual cyclist.

Conclusions:

• A lumped parameter model with linear springs and dampers is a viable approach for modeling the rider.
• This dynamic cyclist model is a significant step toward optimizing off-road bicycle suspension systems.
• The findings provide a foundation for more sophisticated bicycle/rider system dynamics research.