Bicycle
helmets are made up of three essential elements, an outer shell,
an inner shell and a strap-retention system to hold the helmet
in place. Each element has its job to make sure the helmet takes
the abuse and not your head.
A bicycle helmet's Inner Liner
The inner liner is designed to reduce brain injury by compressing
and absorbing the energy of a fall, so your brain doesn't. Brain
damage is a function of rattling and moving around inside the
skull, so best to let the helmet take the brunt of the abuse,
and leave your brain intact for another day.
They are typically made of expanded polystyrene foam that will
crush and crack on impact. It goes into self-destruct mode. It
is for this reason that all helmets should be replaced after a
serious spill, even if on visual inspection it doesn't look damaged.
A bicycle helmet's Outer Skin:
The outer skin, in theory should be as smooth as possible so that
when you get tossed off the bike your head AND helmet will skim
across the ground. A smooth surface reduces friction and is more
likely to slide around obstacles rather then collide with them.
This skin also protects you from sharp penetrating objects like
tree branches and distributes the impact across the face of the
softer foam inner core.
Plastic, fiberglass and even carbon fibre has been used as a
material of choice for the bicycle helmet shell, each with its
own advantages.
Helmet buckles and Retention System:
The
retention system is typically a strap harness inside the helmet.
The harness usually includes a one or two knob system at the back
of the helmet to allow tightening of the bands so that it fits
firmly to your head.
Straps fall from this harness in a Y shaped configuration to
drop on either side of your ear merging at a clip and then to
a buckle under your chin. The straps are usually made of NylonŽ
to offer the strength necessary so they don't snap on impact.
It is important that these bands are adjusted correctly when
chosing a bicycle helmet or you'll never know if it is the correct
size and style until you take it on the road and it proves to
be uncomfortable.
Bicycle helmets are available generally in four different styles
depending on the type of riding that is your passion:
Sport Helmets: for all purpose riding. They have typically
less vents and less sophisticated tensioning systems. They are
also less expensive then their dedicated cousins.
Road Cycling Helmets: The typical road rider is going
for distance and looking for a helmet that is as lightweight as
possible with lots of vents for air circulation
BMX Helmets: These riders know they need more protection
for this aggressive trickster style of cycling, thus the helmets
tend to offer greater protection to the sides and back of the
head and sometimes are full face. They are larger and heavier
than traditional helmets. If your intent is to BMX in the summer
heat, be sure that venting is considered or it will never get
off the shelf.
Mountain Bike Helmets: similar to a BMX helmet with greater
protection for off road use.. running into cliffs and falling
over rocks.
More Information:
Features of
the Best Bicycle Helmets
Giro
Helmets
Bell
Helmets
