Page 6 - index
P. 6
06 GOLF ARTICLE
GRAPHITE SHAFT
PROPERTIES
This is the second part of a three part series in which we will
talk about shaft properties and shaft ftting. In this second
installment, we will discuss about graphite shaft properties
and how they may affect the swing and ball fights.
Property Defnition Role Effect
How the shaft responds to loading and
unloading during the swing.
By placing different materials at different
locations of the shaft, we can vary the Bend Profle infuences launch
EI of the shaft (E stands for “modulus of characteristics and feel. By Soften tip increase
elasticity”, a measure of the stiffness of
the material. I stands for “area moment of varying the butt to tip stiffness launch angle and
ratio, we can infuence how the
spin. To decrease lag
inertia”, a measure of stiffness of the cross ball launches. Also by varying how on the downswing, we
sectional geometry of the shaft). We measure quickly the stiffness changes from can stiffen the middle
BEND PROFILE how stiff or soft along the shaft, or we can one section to another section, we section of the shaft.
measure the stiffness in CPM, at various
points on the shaft. There is no standard; can change the feel.
some prefer to use EI while some think that
frequency measurement at various points is
good enough.
In the past, it was commonly
believed that we needed a low
torque shaft to improve accuracy.
Measures how the shaft twists during the Infuence accuracy/
But with recent advancement in
loading and at impact. material and design, we are now control and feel
TORQUE able to increase torque to improve
feel without sacrifcing control.
By stabilising the cross section of
How a shaft maintains its shape throughout a shaft, the energy is increased Energy transfer and
the swing. and the dynamic defection is club head speed
STABILITY more consistent.
For woods, the goal is to minimise
weight while maintaining the
Club head speed
The dead weight of the shaft. Material and important playing characteristics. (distance), Launch
the type of fber used primarily are the factors For irons and hybrids, the goal is Angle, Spin and
that determine the weight. to create a shaft weight to allow
WEIGHT for appropriate swing weight and Control
optimise stability and consistency.
Material strength
Carbon composite is many times infuences shaft
stronger than steel, so shafts can weight which then
Material strength and durability
be manufactured at much lighter directly affects club
weights head speed, timing
STRENGTH
and club path.
Feel is the hardest attribute to control. We
can’t test for it with machines or robots or
launch monitor and different players have
different opinions. A lot of high modulus Feel can be optimised by tuning
material at 45” (very low torque) increase the torque, stability, and tip Confdence in club
vibration. Shaft manufacturers now use stiffness
alternate angles to control torque and don’t
FEEL
focus on minimising torque as previously
thought.
Hope we now have a better understanding of graphite shaft properties.
In the last part, we will talk about the type of shaft ftting which are commonly available in the market.
GRAPHITE SHAFT
PROPERTIES
This is the second part of a three part series in which we will
talk about shaft properties and shaft ftting. In this second
installment, we will discuss about graphite shaft properties
and how they may affect the swing and ball fights.
Property Defnition Role Effect
How the shaft responds to loading and
unloading during the swing.
By placing different materials at different
locations of the shaft, we can vary the Bend Profle infuences launch
EI of the shaft (E stands for “modulus of characteristics and feel. By Soften tip increase
elasticity”, a measure of the stiffness of
the material. I stands for “area moment of varying the butt to tip stiffness launch angle and
ratio, we can infuence how the
spin. To decrease lag
inertia”, a measure of stiffness of the cross ball launches. Also by varying how on the downswing, we
sectional geometry of the shaft). We measure quickly the stiffness changes from can stiffen the middle
BEND PROFILE how stiff or soft along the shaft, or we can one section to another section, we section of the shaft.
measure the stiffness in CPM, at various
points on the shaft. There is no standard; can change the feel.
some prefer to use EI while some think that
frequency measurement at various points is
good enough.
In the past, it was commonly
believed that we needed a low
torque shaft to improve accuracy.
Measures how the shaft twists during the Infuence accuracy/
But with recent advancement in
loading and at impact. material and design, we are now control and feel
TORQUE able to increase torque to improve
feel without sacrifcing control.
By stabilising the cross section of
How a shaft maintains its shape throughout a shaft, the energy is increased Energy transfer and
the swing. and the dynamic defection is club head speed
STABILITY more consistent.
For woods, the goal is to minimise
weight while maintaining the
Club head speed
The dead weight of the shaft. Material and important playing characteristics. (distance), Launch
the type of fber used primarily are the factors For irons and hybrids, the goal is Angle, Spin and
that determine the weight. to create a shaft weight to allow
WEIGHT for appropriate swing weight and Control
optimise stability and consistency.
Material strength
Carbon composite is many times infuences shaft
stronger than steel, so shafts can weight which then
Material strength and durability
be manufactured at much lighter directly affects club
weights head speed, timing
STRENGTH
and club path.
Feel is the hardest attribute to control. We
can’t test for it with machines or robots or
launch monitor and different players have
different opinions. A lot of high modulus Feel can be optimised by tuning
material at 45” (very low torque) increase the torque, stability, and tip Confdence in club
vibration. Shaft manufacturers now use stiffness
alternate angles to control torque and don’t
FEEL
focus on minimising torque as previously
thought.
Hope we now have a better understanding of graphite shaft properties.
In the last part, we will talk about the type of shaft ftting which are commonly available in the market.
