Interesting diagram shows the impact areas on crash-involved motorcycle helmets. (Source: Dietmar Otte, Medizinische Hochschule Hannover, Abteilung Verkehrsunfallforschung, Germany.) Note that 35% of all crashes showed major impact on the chin-bar area. This means that if you ride with an open-face helmet, you are accepting only 65% of the protection that could be available to your head. If people ride with a shorty or half helmet, they are accepting only 39% of the protection they could obtain. They are literally throwing away 61% of the protection they would have had had they chosen a full-face helmet.