For: A helmet is unlikely to help you if you hit your head very hard on an object. However it reduces the likelihood of you getting a miner head injury if you fall of your bike and hit your head, or ride into a tree branch at slow speed. Therefore wearing a helmet may say you having to spend a few hours in A&E while they check you out, you may also avoid an overnight hospital stray for observation.

For: A helmet is unlikely to help you if you hit your head very hard on an object. However it reduces the likelihood of you getting a minor head injury if you fall of your bike and hit your head, or ride into a tree branch at slow speed. Therefore wearing a helmet may save you having to spend a few hours in A&E while they check you out, you may also avoid an overnight hospital stay for observation.