First you may ask why in the commuting forum? Because we are the cheapest bikers here and this is part of the question. I was recently told by a local LBS that helmets should be replaced every 3-5 years as the styrofoam dries out. (dryrot???). He also said that if you commute everyday that you should replace it yearly(or every 6 months) because of all the banging around it receives. I am going into my 7th year of commuting w/ 2 helmets. 1 is 5-6yo and the other is 2yo. I just ordered new pads for both. So I ask you commuters, do you replace this often? I know my younger one ain't going nowhere but am thinking about pitching the older one. But I am cheap so they both will probably stick around. Later charlie