Shaft fitting

In this post, we would like to share some details about shafts properties and how they can affects the swing and ball flights. In the last section, we will also compare some of the ways shaft fitting are done.  Having said that, we would like to highlight that shaft fitting is just one part of a holistic club fitting.  A properly fitted club is more than getting the right shaft, there are many more parameters like head design and over balance (MOI/SW) that needs to be understood.  Here you go.

Steel Shaft Properties

Property Definition Role Effects
Weight The dead weight of the shaft, e.g. 130g or 95g.How a weight feel is a relative concepts.  For example, a 100 g weight may feel heavy to some but may feel light to other.Shaft weight design in a set can be classified into three types.1) Constant weight. All irons will have (approximately) the same weight.  I.e. from the long irons, e.g. 2i, to the short irons, e.g. PW.  The shaft will be of constant weight.  Most taper tip shafts falls into this category.2) Descending weight.  The weight from the long irons to the short irons gradually get lesser.  Most of the parallel tip shafts (and handful of taper shafts) are of this category.  Descending weight design also make matching a set of irons to MOI or SW more challenging.3) Ascending weight.  In this category, the long iron weigh lesser than the short iron.  This design will somewhat make MOI matching easier as we do not need to add that much of weight to the head (with the current head weight design) Head weight is pretty much constant, so shaft and grip become the primary two means to decrease or increase the total club weight. affects club path, swing speed, tempo and ball striking When the shaft is too heavy for a golfer, it will lower the club head speed,  tends to be stiffer for the golfer and lower launch angle.  The opposite is true.When the weight is too heavy or light, it will affects the tempo/timing of the swing and also negatively affects ball striking.
Wall Thickness How thick the section of the shaft is.Courtesy of True Temper Used to fine tune the shaft with overall stiffness and balance point.Affects the overall flex of the shaft and the feel of the shaft Wall thickness effects the vibration transmitted to the hand and directly affects the feel.  There is no science to explain what launch parameters  it affect though.
Tip Deflection Measurement of tip stiffness as a result of the shaft geometry and well thickness Affects feel and ball flight.  Soft tip tends to launch the ball higher
Butt Deflection Measurement of buff stiffness as a result of the shaft geometry and wall thickness.  Do not confuse this with butt frequency. Butt deflection is measured by clamping the butt 6” and placing a fix weight 22” from the butt.  This eliminate any effects other part of the shaft may have on the butt stiffness. Butt Stiffness measures only the 5” section of the butt. But since the load is placed at the tip and depends on the beam length,  These two variables will affect the measure cpm. Directly driver tip responsiveness Affects tip responsiveness.
Balance Point Is an indication of the material distribution and has a net effect on swing weight. Allows us to manipulate the static weight of the club.
Bend Point Is a result of the butt to tip ratio.Generally three classifications.  High, mid and low. Affects trajectory and feel.
Frequency A method of qualifying the stiffness of a golf club measured in CPM.Raw frequency: the frequency of an untrimmed production shaft or blank shaft.  3 constants, clamp pressure, clamp length, and the mass of the weight used at the tip.Finish club frequency – the frequency of an assembled golf club cut to length

 

Graphite Shaft

Property Definition Role Effects
Bend Profile How the shaft responds to loading and unloading during the swingBy placing different material at different location of the shaft, we can vary the EI of the shaft (EI measures how stiff or soft along the shaft) Influences launch characteristics and feelBy varying the butt to tip stiffness ration, we can influence how the ball launches.By varying how quickly how the stiffness change from one section to another section, we can change the feel. Soften tip increase launch angle and spinTo decrease lag on the downswing, we can stiffen the middle section of the shaft.
Torque Measures how the shaft twists during the loading and at impact. In the past, it was commonly believed that you needed a low torque shaft to improve accuracy.  But with recent advancement in material and design, we are now able to increase torque to improve fell without sacrificing control. Influence accuracy/control and feel
Stability How a shaft maintains its shape throughout the swing By stabilising the cross section of a shaft, the energy is increased and the dynamic deflection is more consistent. Energy transfer and club head speed
Weight The dead weight of the shaft.  Material and the type of finer used primarily are the factors that determine the weight. For woods, the goal is to minimise weight while maintaining the important playing characteristics. For irons and hybrids, the goal is to create a shaft weight to allow for appropriate swing weight and optimise stability and consistency. affects club path, swing speed, tempo and ball striking When the shaft is too heavy for a golfer, it will lower the club head speed,  tends to be stiffer for the golfer and lower launch angle.  The opposite is true.When the weight is too heavy or light, it will affects the tempo/timing of the swing and also negatively affects ball striking.
Strength Material strength and durability Carbon composite is many times stronger than steel so shafts can be manufactured at much lighter weights Shaft weight -> affect club head speed, timing and club path.
Feel Hardest attribute to control.  Can’t test for it with machines or robots or launch monitor.  Different players have different opinions.A lot of high modulus material at 45* (very low torque) increase vibration.  - Use alternate angles to control torque and don’t focus on minimising torque Feel can be optimised by tuning the torque, stability, and tip stiffness Confidence in club

Now, let us talk a little about shaft fitting.  Generally there are four main shaft performance characteristics which need to be considered to properly fit a shaft:

1) Shaft Flex
2) Shaft Bend Point
3) Shaft Weight
4) Club final length

You read about the performance characteristics in the previous section.  The follow table shows a comparison of the four main fitting methods generally offered by shaft companies, OEMs or club fitters.

Fitting Methods: Pros Cons
1) Swing Speed/Speed Charts This is the quickest way to fit for flex and it is very easy to explain to golferA sample speed chart may look something like this:  Generic informationLeast amount of accuracy due to lack of dynamic interactionThis is usually made available on online-shop so golfer can just guestimate what is right.
2) Launch Monitors Launch monitors provide immediate feedback of club performance and wealth of data not available through any other fitting method.Predominantly, the most accurate solution are those radar and high-speed photography based systems.  There are many other innovative low-end solutions around, but we will leave them out of this discussion as they tends to be less accurate and limited data for club fitting purposes. Flightscope, Trackman, Ernest Sports, ForeSight Sports (high-speed photography), Accu Sport (high-speed photography),  AboutGolf (high-speed photography)For putting analysis, we have solutions from Science & Motion’s SAM Puttlab and Quintic’s Ball Roll Software Generally this method is very time consuming as we will need to get golfer to baseline their performance and then capture data with different shaft to make assessment and recommendation. Varying levels of accuracy and interpretation depending on monitor model
3) OEM fitting carts Fast and Efficient dynamic fitting through interchangeable components.Golfer can see and feel club and shaft combination differences.Most OEM brands provide such a cart, e.g. Titleist, TaylorMade, Callaway, Ping and Mizuno. Tied to one manufacturer’s philosophyLimited shaft options in most carts
4) Best of breed Professional independent club fitter will usually opt for this setup and offer them with launch monitor analysis.Typically we can expect minimally 200+ shaft options and 30-40 heads designs to accurately fit a golfer.  Some also deploy databases where they have access to thousand of shaft profiles information.  After analysing the swing profile, a shaft is selected based on its bend profile and a golfer’s reaction to the weight of the shaft.  Fine-tuning is then performed based on the launch condition.Being brand independent, golfer will not be tied to a small number of shaft selections like most OEM Fitting carts. Like Launch monitor method, this is very time consuming considering the many options.

Wiz Golf falls into the best of breed category.  If you would like to have a swing analysis session to see what shaft fits your swing, please drop us a mail at enquiry@wizgolf.com.sg

 

Leave a Reply

Your email address will not be published. Required fields are marked *


nine − = 6

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>