Studies show wearing a bicycle helmet
prevents
sixty percent head injury deaths it also
reduces the overall risk it head
injuries by
eighty-five percent but ever wonder
white cycling helmets are shaped the way
they are or
why serious cyclists don't look like
this writer
wearing a loose fitting tee shirt and
long pants instead
many cyclists wear tight-fitting racing
tape here
is it a fashion statement or is science
specifically
motion dynamics now the reality is it's
probably both writers might want to look
good
but the was in physics require recyclers
to overcome
multiple forces simply put a bike in
motion
and aerodynamic clothing helps to do
that so you're always
trying to balance out that you know the
the best aero position and
you know the most efficient position for
putting up power and catch on a match
the 22
to see what the best combination that
you can get immense okay
just had a permanent one often calibrate
David Salazar helps
cyclists like Mike Byrd ride like the
win by
writing the win in the a2 win title
in Mooresville the most common
misconception that went on all those
that area is blown
over whatever object or person is being
tested
the reality is air is drawn
through the wind tunnel because that way
the airflow is more uniform
is the back in the wind tunnel there are
three giant fans just like this
an air can be pulled through the wind
tunnel up to 85 miles an hour
okay and they're coming on Ste
he wanted to it is normally do what you
know when you're 18
doing special and now we're gonna get
from a biomechanics measurement down as
well as their dynamic data
82 win title is the only wind tunnel in
the world that combines
motion capture technology with
high-speed cameras
and aerodynamic sensors that means that
by a mechanic
and aerodynamic data can be captured in
real time
while the test is happening so cyclist
changes positions
or headgear or alters anything during a
test
the effects can be study immediately it
gives me a chance to find out what I can
be better how can I get faster does it
make a difference if I have a narrow
on the first to the road a quantified
everything it makes your real
you know you can read magazines all day
long and read about this and that
resistance proceeded on their anti the
numbers change in
it's really become very real and here's
why
all those numbers matter cycling is good
exercise
because the writer has to overcome a lot
of forces trying to keep the bike
removing that's why peddling it work
gravity is pulling the bike in the
writer down
drag from air resistance is pushing from
the front there's
vertical ground reaction caused by
friction between the tire in the ground
and proposes in rolling resistance
caused by breaking
and inertia simply getting the fight
make it turn while riding
there's even more force working against
the writer increase the friction on the
wheel
plus torque and centripetal force and
here's the trouble
the was in physics dictate that most to
those forces
can't be changed ready is brevity can't
do anything about that
different players and bike designs can
reduce the friction with the road but
only little fortunately for cyclists
aerodynamic drag is the largest force a
writer has to overcome to get moving
and its the one force a writer can do
something about
anywhere from 80 to 90 percent a power
they're putting out a just overcome that
a resistance so we can help them out you
know 3 45 percent
it's huge for them especially for longer
distances because they're there already
and perhaps
so much power anytime you can help them
it either help them get done with the
race quicker
or just helps them you know takes less
energy linked it to get to the race
the first thing david notices is that
Mike doesn't pedal
evenly so what we're looking at here is
than any trace
now since my kids had surgery on his
right knee we can see it does not track
the same as his left knee
you can look at these patterns and see
this is more curved on the outside where
this is more up and down
but now look at Mike from this side view
in
separate tests he wore a road helmet and
sat in a more
upright position then eat right and
aerodynamic helmet
in it cut position that lowered his
torso
by three degrees you know if you're
looking at his ankles again but we can
compare this to his baseline position so
this outline I took initially when we
ran him
and I can overlaid on this photo so you
can see just how much we brought down
you know not only his head but his back
shape back is changed
and we brought him down quite a bit
and it definitely helped economically a
lot my grand
12 positions in one hour of testing so
looking at
the the baseline to the best we're able
to save in 13 point three percent
a drag savings now at that equates to
twenty miles an hour it would take him
382 what's
to maintain that speed in the baseline
position whereas the new position with
the arrow helmet now it's only takes 337
wants to maintain that position
a what is a measure of power
reducing drag means more efficient
pedaling which means Mike uses
fewer want to power to go just as fast
that saves in energy which I could use
in other parts the race
so crunch the numbers that 44 what's up
our saved
over a 10-mile race would shave 57
seconds
of Mike's race time those same
aerodynamic principles are used to
design everything from bikes and helmets
as we saw at the beginning at the story
to the cars that cyclists ride by
the planes that fly about all in an
effort to save
energy that date on essays a lot energy
for you if you're traveling especially
you know you can be a little rhyme a lot
faster a lot for
save that for you live burglary
