Final answer:
Leaning at the correct angle is important when making a turn to ensure stability and maintain the centripetal force. This principle applies to both bicyclists and ideal banking of roadways.
Step-by-step explanation:
When making a turn, one of the basic principles is to lean at the correct angle. This is because the force exerted by the ground on the wheel needs to be on a line through the center of gravity. The net external force on the system is the centripetal force, which must be supplied by the horizontal component of the force on the wheel. This relationship between angle, speed, and radius of curvature applies to both bicyclists and ideal banking of roadways.