How should a helmet fit?

A helmet should fit comfortably but snugly, without being too loose or too tight, because this ensures optimal protection in the event of an accident. A snug fit means the helmet will stay in place during a ride, which is crucial for preventing it from sliding off or rotating on the head. If a helmet is too loose, it won't provide the necessary impact protection and could compromise the rider's safety.

Additionally, a properly fitting helmet allows for some padding to absorb impact, while not causing discomfort that could distract a rider. It should sit low on the forehead without pushing down uncomfortably and should not interfere with the movement of the ears or neck, allowing for better hearing and visibility. This balance of comfort and snugness is what makes helmets effective in protecting a rider's head.