Nine different models of bicycle helmets testing

Nine different models of bicycle helmets were tested, with 6 helmets of each model submitted to the laboratory for testing to a combination of the AS/NZS2063 and Snell B95 standards tests. All the tests were performed after conditioning in the ambient environment. The following tests carried out and the findings were as follows:

• The test area coverage required by the two standards was similar for all the sizes of helmets, but the area of the head covered by the Snell certified helmets was greater. The more generous coverage of the Snell B95 helmets was also indicated by the slightly higher weights on average for these helmets.
• The order of testing followed AS/NZS 2063-1996, as this was the worst case from the two standards. The AS/NZS 2063-1996 standard requires the impact testing to be carried out before the retention system strength test on the same helmets. This effectively increases the severity of the retention system test as more deformation of the restraint system is likely to occur.
• The Snell B95 dynamic helmet stability test is significantly more demanding of the helmet design than the AS/NZS 2063:1996 static test. The Snell test takes the retention system of the helmet near to its mechanical limits.
• The flat anvil impact energy attenuation tests are included in both the AS/NZS 2036- 1996 and the Snell B95 standards and were made on the front, rear, and top of the helmets. For these tests both group of helmets returned similar results. Further, it is clear that the higher energy of the flat anvil tests to the Snell standard generate a higher acceleration of the headform in this test for both groups of helmets, by about 25%. The safety margin built into the helmets to both standards easily deals with this increase in drop energy. Therefore the helmets to both standards offer the same impact attenuation protection and this is confirmed by the similarity in liner densities found for the range of models tested.
• The kerbstone and hemispherical anvil impact energy attenuation tests were only performed within the Snell B95 Standard. For both these tests the AS/NZS 2036-1996 approved helmets gave noticeably higher headform accelerations, with the average for these helmets exceeding the requirement of 300g. The test variability was also significantly greater for these tests on the AS/NZS 2036-1996 approved helmets. Two of the AS/NZS 2036-1996 helmets failed these tests with the kerb and hemi anvils.
• The sampled helmets certified to both standards gave very similar results in the load distribution test. If one of the AS/NZS 2036-1996 certified helmets, the Rosebank Ms 16, is removed from the test results, then the test variability is significantly reduced. This helmet still met the requirements of AS/NZS 2036-1996.
• The AS/NZS 2036-1996 certified helmets have greater retention system strength in comparison to the Snell B95 helmets. The average dynamic displacement for the Snell B95 certified helmets was close to exceeding the maximum limit of both AS/NZS 2036- 1996 and Snell B95 standards.
• The liner foam density was consistent in all the helmet sizes and both certification standards, with the exception of the Bell Stryker helmet which was higher.
• The AS/NZS 2036-1996 certified helmets are consistently of lower helmet weight across the whole range of sizes than the Snell B95 certified helmets. This is a direct measure of the larger area of coverage of the head given by the Snell standard, as the foam density was similar for all the helmets tested, except for the Bell.