Helmets should be inspected before a ride. Look for cracks or dents in the foam or the foam degrading or crumbling—these are sure signs that it is time for a new helmet. Helmets should last approximately three years, but if you ever crash or drop your helmet, it is strongly recommended you replace it. Check the buckles to ensure a safe fit, and make sure the helmet is properly fitted, covering the forehead and not tilted back. Any local bike shop can check the fit to make sure it is correct or the Bicycle Helmet Safety Institute has a good online reference that covers fitting a helmet.