re where to put your helmet on apr gmt ryan cousineau compdyn questor org ryan cousineau said cb don t be so stupid as to leave your helmet on the seat where it can cb fall down and go boom ryan another good place for your helmet is your mirror i kid you not this is very bad advice helmets have two major impact absorbing layers a hard outer shell and a closed cell foam impact layer most helmets lose their protective properties because the inner liner compacts over time long before the outer shell is damaged or delaminates from age dr hurt tested helmets for many years following his landmark study and has estimated that a helmet can lose up to of it s effectiveness from inner liner compression i have a video he produced that discusses this phenomenon in detail puncture compression of the type caused by mirrors sissy bars and other relatively sharp objects is the worst offender even when the comfort liner is unaffected dents and holes in the foam can seriously degrade the effectiveness of a helmet if you are in the habit of parking your lid on the mirrors i suggest you look under the comfort liner at the condition of the foam if it is significantly damaged or missing replace the helmet jerry lotto lotto lhasa harvard edu msfci hogssc bcso ama dod chemistry dept harvard univ it s my harley and i ll ride if i want to
