The Bicycle Helmet Myth – True and Not

Apparently there is a popular myth that city cyclists have been bandying about for years – that they are more likely to be hit by a car if they wear a helmet than if they don’t. This myth so intrigued Ian Walker, a psychologist at the University of Bath, that he decided to put it to the test. Walker fitted his bike with a special ultrasonic sensor that would measure how close cars came to him as he cycled to and from work. To complete the experiment he wore a helmet every second day and rode bare-headed every other day for two months.

His findings may surprise drivers, but they won’t surprise anyone who has ever had cause to ride a bicycle on busy city streets: on average, when wearing a helmet, cars came 8.5 cm (3.35 inches) closer to him and his bike than when he left his helmet at home. Helmet-haters are vindicated and everyone can throw their uncool and annoying helmets away.

Except that they can’t, because the results are misleading. Bicycle helmets aren’t worn to reduce the occurrence of accidents, they’re worn to reduce the impact of accidents and to prevent irreparable brain damage.

According to statistics from, bicycle helmets reduce the risk of head injury by about 85% and the risk of brain injury by 88%. They also provide a significant measure of protection for the face and forehead. In addition, studies have shown that bare-headed cyclists are 14 times more likely to die in a crash than their helmeted counterparts.

Before buying a helmet, cyclists need to consider their cycling habits and needs. For instance, are they road cyclists or off-road cyclists, do they cycle mountain trails or city streets? Road helmets can be distinguished from off-road helmets by their longer, sleeker and more aerodynamic design with narrow air vents. The vents on off-road helmets are wider because it’s assumed that cooling off takes precedence over speed.

It’s very important that helmets fit properly. Helmets should be snug on top of riders’ heads; they should be level and shouldn’t tilt to the back or to the front. The helmet should fit about two finger widths above the eyebrows to achieve maximum protection and a clear line of sight. Helmets shouldn’t be loose on cyclists’ heads, they shouldn’t swivel or fall forwards or backwards, but they shouldn’t pinch and be too tight either. Helmets usually come with extra sponges for cyclists who need to make the helmet smaller. The sponges that are already in the helmet can be removed to make extra space should it be needed.

Studies have shown that children are more likely to wear bicycle helmets regularly if their parents set a helmeted example. About 98% of children wear helmets if their parents do, but that figure drops to just 30% when their parents cycle bare-headed. Given the fact that children aged 10 – 14 have the highest figures for serious brain-related injuries sustained in bicycle accidents, parents have good incentive to strap up.

Helmets have a lifespan of around 4,500 miles (7242km), which translates into roughly 5 years (for average recreational cyclists, not professionals). Beyond that, the materials start to break down and the effectiveness of the helmet is compromised. Helmets should also be thrown away after an accident, because no matter how light the damage appears to be, cracks in the plastic and dents in the protective foam will reduce the helmet’s protective ability.

Walker’s experiment, far from giving cyclists license to feel the wind in their hair, underlines the importance of wearing a helmet at all times. While conducting his study, Walker was knocked off his bike twice, once by a truck and once by a bus, both times he was wearing his helmet, and both times he got up with skull and brains intact. Who needs more incentive than that?

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