Originally Posted by N_C

Used to wear head bands. Until I found out it is not really a good idea to wear anything on your head under your helmet. I'm guessing it is because the helmet could slip off of your head and not fully protect you in the event of an accident. I don't know if a head band or doorag can cause a helmet to slip around or off the head, even partially, when an impact is occurs, or how it can happen. And I don't know if this has been tested for & that is why helmet manufacturers recommend against it. I just know it is strongly recommended that you not have anything on your head under the helmet.