Bike helmets are effective at preventing head injuries and other serious injuries in the event of a crash. They work by absorbing the energy from the impact, which can help to reduce the severity of an injury.Despite their protective benefits, however, bike helmets are not 100% effective. In some cases, they can even increase the risk of injury. For example, if a cyclist falls off their bike but their helmet remains attached to their head, they may be more likely to suffer a neck injury.Ultimately, whether or not you decide to wear a bike helmet is up to you. However, it is important to keep in mind that they can help reduce your risk of serious injury in the event of a crash.