Originally Posted by
bpcyclist
That is so interesting, thank you. So, but, that would suggest if I live in San Diego or Barcelona that my time frame for helmet replacement should be quite a bit different than if I live in Manchester or Seattle, right? Do you think the bike shops in sunnier climates know this?
Perhaps although altitude might make a larger difference. The UV flux is greater at Denver’s altitude than it is at sea level. Ozone, which would also have an influence, is greater at higher altitudes because of the higher UV flux and its interaction with hydrocarbons from fuels. If you stored the helmet in an area where there are lots of electrical machines, you’ll have higher ozone levels as well.