There is no definitive answer to this question, as it depends on both the specific helmet and the type of impact it is protecting against. However, in general, all bike helmets offer a certain level of protection against impacts, both minor and major.It is important to remember that not all helmets are created equal, and some are better at protecting against specific types of impacts than others. For example, a helmets designed specifically for mountain biking may be better at protecting against falls and other impacts encountered while riding off-road, while a road cycling helmet may be better at protecting against collisions with cars.In most cases, however, any bike helmet will offer some level of protection against both minor and major impacts. This is why it is so important to always wear a helmet when riding a bike, regardless of the type of riding you are doing.