Which part of a helmet helps to absorb shock?

The impact-absorbing liner is designed specifically to absorb and dissipate the energy from an impact, making it a crucial component of a helmet in terms of safety. This liner is typically made from materials such as expanded polystyrene foam, which compresses upon impact to reduce the force transmitted to the wearer's head. By absorbing shock during a collision, this part significantly lowers the risk of severe head injuries.

The outer shell, while important for providing structural integrity and protection against abrasions, does not absorb impact energy; it primarily serves as the first line of defense against external objects. Comfort padding provides a snug fit and enhances comfort but does not contribute to shock absorption in the event of a crash. The retention system, which includes the straps and buckles that keep the helmet secure on the rider's head, is essential for ensuring that the helmet remains in place during an incident but does not play a role in shock absorption.