What type of friction is desirable between tires and the riding surface?

Rolling friction is the desirable type of friction between tires and the riding surface because it allows the cyclist to maintain momentum and stability while minimizing resistance. This type of friction occurs when the tire rolls over the surface, creating less drag compared to sliding or skidding.

The primary goal in cycling is to achieve a balance between grip for controlling the bike and the energy loss that comes from friction. Rolling friction provides sufficient traction to maneuver safely and effectively while allowing for forward motion with minimal energy expenditure. It is essential for maintaining speed and efficiency, especially in public safety cycling where quick response and agility can be critical.

In contrast, static friction, which becomes relevant during starts and stops, is important for gripping the surface before the tire begins to roll. Dynamic friction, on the other hand, occurs when the tire slides or skids, which is less desirable as it can lead to loss of control. Air resistance is also a factor that affects cycling performance but is not classified as a type of friction between the tire and surface.