What is the criterion for a bicycle's wheel size?

The criterion for a bicycle's wheel size is that at least one wheel must be more than 14 inches in diameter. This specification ensures that the bicycle can be efficiently and safely ridden, as larger wheels provide better stability, traction, and performance on various surfaces. The emphasis on diameter helps in delineating between what qualifies as a bicycle and other smaller wheeled vehicles, ensuring compliance with safety standards and regulations governing bicycles.

This particular requirement reflects industry standards and is vital for ensuring that bicycles can navigate road conditions effectively. Smaller wheels, such as those less than 14 inches in diameter, typically limit the efficiency and handling characteristics of a bicycle, making the specification important for both rider safety and performance.