361: The Science of Cycling

Ever wonder why it's harder to cycle up a hill? Or why it's easier to ride on smooth asphalt with skinny tires instead of wide tires on gravel? Turns out, there's an answer: SCIENCE! On this edition, we delve into the (very) basics on what works against us while riding, and how we convert food into motion!

The Science of Cycling

Programming notes

• Best of next week
• Spring tour preview the week after, followed by the tour journal!
• The march to the ten year anniversary of the show commences… Live show to celebrate things June 8th, time TBA, but mark it down now. It will be podcasted the following week but always down for some live banter.

The Physics of Cycling

1. Rolling Resistance

• Definition: Explain rolling resistance as the force that opposes the motion when an object (like a bicycle tire) rolls on a surface.
• Factors Affecting Rolling Resistance:
  • Tire Type and Pressure: Soft tires or low pressure increases resistance.
  • Surface Type: Rough surfaces like gravel increase resistance compared to smooth surfaces like pavement.
• Real-World Example: Compare how it feels to ride a bike on a sandy beach versus a smooth bike path.

2. Air Resistance (Drag)

• Definition: Air resistance is the force air exerts against a moving object.
• Factors Affecting Air Resistance:
  • Speed: The faster you go, the more air resistance you face.
  • Rider’s Position and Shape: Explain how being more streamlined (like bending low on the bike) reduces air resistance.
• Practical Tip: Demonstrate with hands outstretched vs. hands close to the body while riding to feel the difference.

3. Energy and Power

• Energy Definition: The ability to do work, like pedaling a bike.
• Power Definition: How quickly you can use energy (pedal) to move.
• Conversion of Energy: Discuss how food energy converts into mechanical energy to pedal.
• Measurement: Mention that power can be measured in watts, like how bright a light bulb is.

4. Gravity and Hills

• Gravity’s Effect on Cycling:
  • Uphill: Gravity makes it harder to pedal uphill because you are working against it.
  • Downhill: Gravity helps you go faster downhill.
• Energy Use: Explain how more energy is needed to pedal uphill and less energy is used when coasting downhill.
• Practical Tips:
  • Gear Usage: Using lower gears on uphill and higher gears on flat or downhill.

The Biomechanics of Riding

1. Human-Bike Interaction

• Pedaling Efficiency:
  • Definition: How effectively a rider can convert their energy into motion.
  • Factors Affecting Efficiency: Foot position on the pedals, the smoothness of pedaling, and maintaining a steady rhythm.
• Ergonomics of Bicycle Frames and Riding Positions:
  • Frame Size and Shape: Importance of having a bike frame that fits the rider’s body to avoid discomfort.
  • Riding Position: Discuss how different riding positions (upright vs. leaned forward) affect comfort and speed.
• Practical Tip: How to adjust a bike to fit (seat height, handlebar position).

2. Muscle Work and Efficiency

• Muscle Groups Involved in Cycling:
  • Main Muscles: Legs (quadriceps, hamstrings, and calves), but also mention the core and arms for balance and control.
• Efficiency in Muscle Use:
  • Warm-Up: Importance of warming up muscles to prevent injuries and improve performance.
  • Stamina and Strength: How regular riding improves muscle strength and cardiovascular health.
• Bicycle fitting can improve efficiencies

3. The Role of Gearing

• What is Gearing?:
  • Definition: Gearing is a way to adjust how hard or easy it is to pedal.
  • How Gears Work: Explain the basics of chainrings and cogs and how changing gears changes the resistance felt when pedaling.
• Choosing the Right Gear:
  • Uphill and Downhill Riding: Using lower gears for uphill to make pedaling easier, and higher gears for downhill or flat surfaces to go faster.
  • Cadence: Keeping a steady pedaling speed (cadence) to maintain efficiency.
• Practical Tip: Encourage trying different gears during a ride to find what feels best for different terrains.