Gear Shed   Should I Replace My Bike Helmet?   The elements will
take their toll on your bike helmet. Via Shutterstock     Photo:
Maxim Petrichuk  A:Excellent question. As someone who has twice
dodged severe head injuries because of my diligent wear of a
bicycle helmet, I’m pretty sensitive to this topic.  And you
raise the exact point—what effect does sweat and the sun have on
a helmet? And the answer is this: Quite a bit. Sweat and the
salts it releases are acidic and corrosive, even eating away at
plastic. And the sun is simply brutal on plastics, which is why
any pack you wear for a few summers will start to fade (and the
fabric greatly weaken).  So what to do? You can take a few steps
to prolong the life of a helmet. Every other week or so, dunk it
in a bucket of cool water and swish it around some. That will
help clean out dried sweat. And of course, try to store it out
of the sun, someplace dry and cool.  Otherwise, I really
recommend getting a new helmet every other year or so, if you’re
a real consis