I treat my bicycle helmet (wide-spread brand of a German manufacturer) like a raw egg. It has never fallen down a cabinet, a table or the bicycle handlebars, not even in daily use it has been exposed to an impact. It is cleaned with nothing but a slightly moist cloth without the use of chemical agents. In recent times I’ve read in cycle magazines and articles of the daily press that a helmet should be replaced every five years, as the material were subject to “fatigue”: I bought my helmet in summer 2008. What is your opinion? Do you think I should actually replace my helmet?

Reply by Dirk Zedler, TOUR technology expert and bicycle expert

Helmet safety is in fact an issue that generates contradictory statements. In most cases manufacturers and specialists express a rather cautious opinion, for different reasons: On the one hand the helmet material ages and becomes brittle. Due to the evaporation of plasticizers, UV radiation and the change of heat and cold elasticity and shock absorption capability may decrease. Furthermore, with the duration of the use there is an increasing risk of crack formation in the supporting substance. What has also happened is the breakage of the buckle with very low temperatures, i.e. a clear sign of aging. All these are relevant points substantiating that a helmet ages and should be replaced sometime for the cyclist’s safety. However, as everyone treats his helmet in a different way you cannot conclude a general statement when it should be replaced. A positive point after all is that helmets are offered at more and more reduced prices with clearly improved technical characteristics at the same time. A top model offered ten years ago at about 200 Euro can be purchased at less than half of the amount in these days. In my opinion there are therefore few reasons speaking against replacing an often used helmet every couple of years.