A bike helmet is not to be considered a one-time investment. Bike helmets have a shelf life and need to be replaced once in a while – even if they’re not involved in a crash. Daily use also takes its toll on a helmet – even if you treat it carefully. But how long do helmets last? Experts agree that bike helmets last for 3-5 years and after that, they should be replaced.
Most people know that a helmet should be replaced after a major crash. Sometimes it’s obvious, but not always. Even a lighter crash that you walk away from could affect the EPS padding in a way that makes the helmet unsuitable for further use. Even if the protective EPS appears to retake its usual shape, you can’t be sure that it can absorb the energy and offer the same level of protection in a second impact. A crash could also affect things like straps and fit systems, which are vital for properly securing the helmet to your head. In other words: not replacing your helmet after a crash means unnecessarily cutting into safety margins.
Then there is the sun, which makes bike helmets deteriorate invisibly. UV rays affect the shell of the helmet, which risks becoming brittle with time. That’s why many helmet manufacturers say to keep your helmet in a cool, dark place when not in use.
But even daily use, without dramatic events, wears out a helmet over time. You bump into things and knock your helmet around while carrying it, or maybe accidentally drop it on the floor. No big deal, but in the long run even small things that don’t leave any visible traces can impact the structural integrity of the helmet.
How long helmets last and how often you should change your bike helmet is largely a question of how and how often you use your helmet. But every 3–5 years is a good rule of thumb. If you ride your bike daily, it will obviously be more exposed to sun and general wear and tear than if you only use it a couple of times a month.
The last reason to change your helmet often is that the development of safer bike helmets is an ongoing process. A brand-new helmet is likely to be a better helmet in general. It’s probably lighter and better ventilated, with a better fit and made from better materials, and it will quite possibly also make you look cooler.