POSE METHOD OF TRIATHLON TECHNIQUES
 CHAPTER
29.
The Complex Nature of a Simple System
It's a bit of enduring folk wisdom that the bicycle is the
most efficient form of human transportation ever developed.
Indeed, when compared with the other tri–sports, the
efficiencies are obvious: with roughly the same expenditure
of effort, a cyclist moves roughly three times as fast as
a runner and ten times as fast as a swimmer.
In the larger scheme of human movement, the humble bicycle
will never equal cars, trains or planes for speed, but in
terms of moving vast quantities of people throughout a metropolitan
area, the bicycle remains unmatched for minimal expenditure
of non–renewable energy sources and the ability to get
its passengers as close as possible to their ultimate destination.
The bicycle is quite simply a marvel of human engineering
(Fig.29.1). And the combination of a rider and a bike creates
an elegant system for human movement. Riding is not something
you do to a bike, it is something you do with a bike. In a
sense, the marriage of cyclist to bicycle created the first
cyborg, the original man/machine combination. No matter how
fast a bike looks or feels, its average land speed without
a human aboard remains resolutely stuck at zero miles per
hour.
As for a human without a bike, figure about eight, maybe
ten miles per hour for anything beyond an all–out sprint.
So, when we talk about cycling technique, what we're really
talking about is systems engineering — devising the
optimum means for a human to interact with a bicycle for the
most efficient forward progress.
This means we have to figure out strictly mechanical efficiencies
as well as balancing anatomic and aerodynamic considerations,
not to mention keeping the all–important psychological
considerations at the top of the list.
Whew! For such a seemingly simple device, the art (or science)
of riding a bicycle can be stunningly complex. Perhaps that
explains the paradox that no matter how many studies of cycling
technique we have from a mechanical or psychological viewpoint,
the question of pedaling technique itself as a human movement
remains unresolved.
If you study the technical literature of cycling, you'll
find reams of information and conjecture about one cycle of
a pedaling stroke, but virtually nothing about the whole picture
of pedaling as an interaction between the athlete and the
bicycle as a means of improving overall cycling performance.
So, that's what we want to start with here: a discussion
of pedaling technique as an integral system of interaction
of the athlete/machine with the external environment. In this
discussion, we will focus on gravity, balance and the optimum
application of body weight as the primary consideration in
developing proper pedaling technique.
No doubt you're now thinking, hold on, what do gravity, balance
and body weight have to do with riding a bicycle fast?
Only this — everything!
Look at it this way. The pull of gravity leads to appearance
of the body weight and its inertia. Unless some action is
taken to reassign the force of gravity, it will keep any given
object rooted to its spot. In other words, any body will stay
where it is, on its current support, until that body is released
from its balance on that support.
Now picture this particular pose (Fig.29.2). As a cyclist,
you are standing on your pedals, clipped in, with your feet
in the three and nine o'clock positions, perfectly motionless,
in what is commonly called a track stand. In most cases, what
will happen next is that you will lose your balance and gravity
will cause you to fall to one side or the other. Let's face
it, most of us just aren't that good at track stands and we'll
fall over just like that guy on the tricycle in the old Laugh–In
re–runs (Fig.29.3).
But you don't want to fall; you want to move this integrated
unit of you and your bicycle in a forward direction. How do
you do this? Most people would answer that you do this by
pushing down on the pedal in the three o'clock position, reasoning
that this active push moves the pedal downward, which rotates
the chain, which engages the rear derailleur that powers the
rear wheel and ultimately propels the integrated unit of you
and your bicycle down the road.
But here's the catch: you can't simply push down on the three
o'clock pedal. Why not? Remember, you're perfectly balanced
on the support of the two pedals, with exactly half of your
body weight on each pedal. No matter how strong you think
you are, there is no pushing movement you can perform that
will overcome the perfect balance you have established.
In order to achieve forward motion, you will have to lose
that perfect balance and transfer a greater percentage of
your body weight from the nine o'clock pedal to the three
o'clock pedal. To do this, you unweigh on the rear pedal (Fig.29.4),
causing more of your weight to be transferred to the front
pedal, which sets off the desired chain of events resulting
in forward motion. This forward motion was not caused by pushing
on the pedal; in fact, you didn't push at all.
And there you have it. With one simple movement, shifting
the body weight on support, you have not only started the
bicycle moving in the proper direction, but you have fundamentally
altered both your psychological and biomechanical concepts
of what riding a bike really is.
Your prior psychological understanding of cycling was that
it was an arduous push–pull task by which the human
body propelled a mechanical conveyance, the bicycle, forward.
Now you can view cycling as a process by which an integrated
unit moves forward through time and space by rapid repetition
of the loss and gain of balance on support.
Biomechanically, your previous concept of cycling involved
an attempt to apply uniform force to a pedal and crank arm
through 360º degrees of rotational movement. In this
view, the human legs do all the push/pull work and the mechanical
elements of the bike transfer that leg–generated force
into forward motion. Your new biomechanical picture of cycling
is that the legs are the transmitters of your shifting body
weight, which, amplified by gravity, is the true source of
the power that drives you forward.
Just like all human movement, riding a bicycle can be reduced
to a very fundamental equation. From a stationary position,
where the body is balanced on support, movement results from
a loss of balance on support, followed by an alternation to
balance on new support.
In running, support is clearly found when the feet touch
the ground. In cycling, just as clearly, support is realized
when body weight balances on the pedals.
These fundamental psychological and biomechanical views of
cycling will form the basis for all the techniques that will
allow you to develop a more efficient pedaling technique and
ride a bicycle further and faster.
The key is to now look at the athlete/machine system that
differentiates cycling from running and structures the most
favorable conditions possible for rapidly and repetitively
changing support from one pedal to the next, as balance is
continually lost and regained.
For the moment, and only for the moment, we're going to set
aside two very important factors: the technical construction
of the bicycle itself and the aerodynamic positioning of the
body on the bicycle. What remains, and what determines cycling
efficiency, is pedaling skill, the art of performing a full
360º degree rotation of the pedal over and over again.
Not surprisingly, the most important element of pedaling
skill is the precise application of power. Ah, power. How
we lust for power. Whether we seek it through hill climbing,
weight training or the injudicious ingestion of banned substances,
cyclists are gluttons for power. But to be used to full effect,
power first must be understood.
Power, in purely technical terms, is the amount of work performed
over a certain unit of time. The formula is simple: power
(P) equals to work (W) divided by unit of time (t) or to force
(F) multiplied by speed (v):
P=W/t=Fv
In rotational movement, such as pedaling a bicycle, power
is determined by the force moment (Fd) multiplied by angular
velocity (w–omega):
P=Fd w
where the angular velocity is expressed as the number of
rotations per unit of time (aka cadence). The force moment
is determined as the product of the force module (F) and its
arm (d):
M(F)=Fd.
Cadence (what we would call rpm in our cars) is the number
of rotations of the pedal per unit of time (T=n/t), where
n is the number of rotations and t is the time unit.
Hence, and somewhat obviously, the greater the force moment
and cadence are, the higher the power output and velocity.
So it stands to reason that improving your pedaling technique
is intrinsically connected to both higher power output and
faster pedaling speed.
Finally, and to answer the question before you ask it, the
tandem imperatives of pedaling efficiency and aerodynamic
positioning serve to determine the optimal position of the
rider on the bike. In other words, your best position will
be the one that optimizes your ability to use gravity to transfer
your body weight to the pedals.
How do we determine that optimal position? In the next two
chapters, we'll discuss separately the concepts of force moment
and cadence and then see how they combine to guide you to
the perfect position on the bike.
ORDER FROM SHOP BELOW
Pose
running website
PoseTech
shop |
