The reasons why a cyclist chooses to wear a helmet – or not – vary, and are influenced by many different factors. The fear of ruining one’s hair or appearance carries just as much weight as factors such as personal experience, the numbers of cyclists on the roads in the area, the type of bicycle, the purpose of the journey and, last but not least, the legal requirements.
Generally speaking, there is a wide variety of helmet models and designs available on the market. The number of products available is as large as the price range. The fundamental requirements are defined in a number of standards, such as EN 1078, CPSC, JIS T 8134, and CAN/CSA-D113.2-M89 (R2014). These standards must be complied with in their respective regions. Providing they meet these basic requirements, however, manufacturers have a large degree of creative freedom in terms of the design. In order to gather information on cushioning behavior, DEKRA subjected a number of different helmets to impact testing in a non-standardized series of tests.
In order to generate added value, the team deliberately chose to use a test that is not included in the same form in the European standard EN 1078. For the purposes of this test, each helmet was fitted onto a steel test head equipped with measurement technology, positioned at an angle of 30 degrees from the vertical, and hit with a round test specimen weighing five kilograms. The test specimen was dropped onto the helmet from heights of one and two meters. The resulting energy, which was transferred into the helmet, was thus 50 or 100 joules respectively. This load applied at a point occurs in a number of real-life accident situations, for example if the head of the cyclist strikes a solid part of a vehicle during the col-lision, such as the A-column or the edge of the roof above the windshield. Of course, the vehicle’s sur-face geometry would not usually match the hemi-spherical test specimen; despite this, it is still possible to draw conclusions with regard to a helmet’s cushioning behavior based on this type of impact.
For this series of tests, a number of different hel-mets were purchased from a large German online shop; two older, used helmets were also tested. All the conventional bicycle helmets demonstrated an excellent protective effect during the impact tests. The shell and structure of the helmets effective-ly distributed the force exerted by the test projectile at the specific point onto the inside section that touched the head. In addition to this, deformations and breaks in the rigid foam of the helmet shell absorbed energy, further reducing the load that acted on the head.