How long does a helmet last?

[shootingstar]

I seriously wonder if material degradation depends also how often it is worn anyway and exposed to the elements day after day.

I see my helmet as protection or reducing abit of risk for low-medium impact injuries.

For the past few months, I've responding to blog posts on other blogs, on defending the usefulness of wearing a helmet ...with really anti-helmet cyclists. I'm actually tired of hearing their arguments.

So I see my position as incredibly minor (wearing a helmet that has never been cracked but a bit older than 5 yrs.) vs. theirs...refusing to wear a helmet.