Chris Rissel and a colleague from the university's school of public health have found in a study that the 1991 helmet law was not the main reason for the decrease in the number of head injuries among cyclists. Breath tests and other measures improving road safety may more likely be the reasons for the lower number of reported head injuries.

In their study of the ratio of head injuries to arm injuries among cyclists admitted to hospital between 1988 and 2008, they found that most of the fall in head injury rates occurred before the law took effect. They also found that the ratio of head injuries to arm injuries continued to decline after the law was imposed and this indicate that other factors led to the reduced rate of head injuries.

Rissel recommended repealing the law in one city for two years to prove their claims.

The researchers said the law has its own disadvantage; it discourages casual cycling. Without the law, more people may use a bike for errands or visiting friends thereby improving health rates.

They added that having no such law may even reduce injury rates in cycling as having more cyclists on the road would make motorists get used to avoiding them.

Rissel noted that only New Zealand had adopted the said law.

Meanwhile, Bike NSW was not convinced by the researchers' findings and recommendations. The group's chief executive, Omar Khalifa, said the data in the researchers' study was incomplete and not compelling. Khalifa said the researchers should have included in their study the number of riders who did not report a head injury.