Bike HelmetBike Helmets are designed to lessen impacts to the head of a cyclist in falls while minimizing side effects such as interference with peripheral vision. They are specified to withstand simple falls onto a flat surface without other vehicles being involved.
Bicycle helmets should always be discarded after any accidents.
There are two main types of helmet: hard shell and soft/micro shell (no-shell helmets are now rare). In both types, impact energy is absorbed as a stiff foam liner is crushed, up to the point where the liner is crushed to its minimum thickness, or the helmet shatters, after which no further energy is absorbed.
Full Article
