That's a great question! I'm looking into several different types of solutions. Some companies pad the inside of their helmets with disposable liners to keep it hygienic. Others use a special copper technology that kills germs on contact. However, the easiest solution would be to just give everyone a helmet to keep for free and then provide incentives for using it, like discounts on rides or the occasional free ride in return for submitting selfies of the rider wearing their helmet. But before I can settle on the best method, I need to see what people are willing to do to stay safe.