Helmets are inconvenient when getting off the bike to shop or go to class.
Response: Putting a helmet on takes less time than putting on bike gloves, but it does add another step every time you get on the bike, and we agree that it can be a nuisance on very short trips from one store to another. So is fastening your seat belt in a car, but you do it for safety. The helmet can be left with the bike, locked if the bike needs to be locked in that location.
Helmets are not effective except in minor crashes.
Response: We have ample evidence from medical studies that helmets are indeed highly effective, and you will find references on our statistics page and our Journals page. Although bicycle helmets are tested in labs in impacts at 14 miles per hour, they usually do a fine job of protecting the rider in a crash where the initial forward speed is higher, because the severity of the impact is normally determined by the closing speed of the head and pavement, not by the rider's forward motion. Research on crashed helmets shows that most people hit the ground at a relative speed of about 10 MPH. If a rider is hit by a car or hits a brick wall at 30 mph and the head takes a direct blow at that speed, no helmet will prevent injury or death. But that type of crash is rare, and helmets are designed for the severity of the most frequent crash types.
As a reality check, ask any club cyclist about helmet effectiveness. They have shared experience that gives them more perspective on crashes. Club cyclists were the first to adopt helmets in the US, and the first to see the results. You will see helmets on all or most of the riders on virtually any club ride in the US. Among racers, the United States Cycling Federation (now USA Cycling--our road racing organization) adopted a mandatory helmet rule in 1986, because every year two or three riders were being killed in their races and more were suffering head injuries. In the years since it has been rare for a racer to die in a US race, even though their crashes occur at racing speeds. We havea page up on helmet protection limits.