Abstract: Disclosed golf club heads include a body defining an interior cavity, a face, a sole, a crown, and a hosel. Certain embodiments include a weight channel positioned in the sole and defining a path along the sole. Some embodiments include a weight member positioned in the weight channel that is configured to be adjusted to any of a range of selectable positions to adjust mass properties of the golf club head. A fastener may be configured to secure the weight member in any of the selectable positions, while the fastener itself, regardless of where the weight member is positioned along the path, may be secured to the body at a fixed location that is independent of the position of the weight member along the path.

Abstract: Disclosed golf club heads include a weight channel positioned in the sole and defining a path along the sole. A weight member positioned in the weight channel can be adjusted to any of a range of selectable positions to adjust mass properties of the golf club head. A fastener secures the weight member in any of the selectable positions, while the fastener itself, regardless of where the weight member is positioned along the path, is secured to the body at a fixed location that is independent of the position of the weight member along the path. Part of the weight channel and weight member can be covered by an overhanging portion of the sole, which can form a sit pad. The overhanging portion can be part of a composite sole insert.

Abstract: Disclosed golf club heads include a body defining an interior cavity, a face, a sole, a crown, and a hosel. Certain embodiments include a weight channel positioned in the sole and defining a path along the sole. Some embodiments include a weight member positioned in the weight channel that is configured to be adjusted to any of a range of selectable positions to adjust mass properties of the golf club head. A fastener may be configured to secure the weight member in any of the selectable positions, while the fastener itself, regardless of where the weight member is positioned along the path, may be secured to the body at a fixed location that is independent of the position of the weight member along the path.

Abstract: A shaft set 2S includes a first shaft SF1, a second shaft SF2 shorter than the first shaft SF1, and a third shaft SF3 shorter than the second shaft SF2. At least the second shaft SF2 and the third shaft SF3 each include butt partial bias layers s3 and s4. Weights of the butt partial bias layers s3 and s4 are increased as the shaft is shortened. At least the first shaft SF1 and the second shaft SF2 each include tip partial bias layers s10 and s11. Weights of the tip partial bias layers s10 and s11 are decreased as the shaft is shortened.

Abstract: A diagnosis server includes a storing section configured to store exercise data of respective users and diagnosis criteria of respective customers and a processing section configured to perform diagnosis on the basis of exercise data of a user designated from a terminal of a customer among the exercise data of the respective users and diagnosis criteria of the customer among the diagnosis criteria of the respective customers and provide the terminal of the customer with a diagnosis result.

Abstract: A shaft 6 includes a tip end Tp and a butt end Bt. If a shaft length is defined as Ls, a distance between the butt end Bt of the shaft and a center of gravity G of the shaft is defined as Lg, and a ratio of the distance Lg to the shaft length Ls is defined as a ratio of the center of gravity of the shaft, then the ratio of the center of gravity of the shaft is equal to or less than 47%. The shaft length Ls is equal to or less than 991 mm. If a forward flex is defined as F1 (mm) and a backward flex is defined as F2 (mm), a flex point ratio C1 of the shaft calculated by the following formula (1) is equal to or less than 39%: C1=[F2/(F1+F2)]×100]??(1).

Abstract: A method includes exciting a work piece, measuring a dynamic response of the work piece with an optical imaging system and calculating a damping factor and a Q factor from said dynamic response. The method links two processes: an optical imaging system to output dynamic motion response data, and using the data to obtain a damping factor and a Q factor.

Abstract: A method includes exciting a work piece, measuring a dynamic response of the work piece with an optical imaging system and calculating a damping factor and a Q factor from said dynamic response. The method links two processes: an optical imaging system to output dynamic motion response data, and using the data to obtain a damping factor and a Q factor.

Abstract: Examples of methods, apparatus, and systems to custom fit golf clubs by providing gapping determination are generally described herein. Other examples may be described and claimed.

Abstract: A club 2 includes a head 4, a shaft 6 and a grip 8. A club length L1 is 45 inches or greater and 48 inches or less. A ratio (Wh/Wc) of a head weight Wh to a club weight Wc is equal to or greater than 0.71. A moment of inertia Ix about an axis of a swing is equal to or less than 6.90×103 (kg·cm2). However, when the club weight is defined as Wc (kg); an axial-directional distance between a grip end and a center of gravity of the club is defined as Lc (cm); and a moment of inertia about the center of gravity of the club is defined as Ic (kg·cm2), the moment of inertia Ix (kg·cm2) is calculated by the following formula (1).

Abstract: Provided is a golf club having a head disposed at a front end of a shaft and a grip disposed at a back end of the shaft. A club weight is not smaller than 290 g, and a ratio (head weight/club weight) of a head weight to a club weight is not lower than 0.67 but not higher than 0.72. When a distance from the front end of the shaft to a center of gravity of the shaft is LG and when a full length of the shaft is LS, 0.55?LG/LS?0.67 is satisfied, and when a frequency of flexural vibration of the club is F, 240 cpm?F?280 cpm is satisfied.

Abstract: A method relating to an improved fitting system for a golf club shaft is disclosed herein. More specifically, the present invention utilizes specific data gathered from the golfer's golf swing itself to determine the best performing golf club shaft for this particular golf swing. Even more specifically, the present invention relates to the utilization of infrared motion capturing cameras to record the location data of a golf club shaft throughout a swing. Based on the location data captured, one or more dynamic behavioral characteristics can be calculated to determine one or more preferred shaft characteristics. Using the preferred shaft characteristics, a shaft can be recommended for the golfer having this particular golf swing. The current inventive fitting methodology is preferred to the archaic fitting method of using data gathered from the result orientated ball flight data together with a tedious process of having to try numerous different shafts.

Abstract: A method relating to an improved fitting system for a golf club shaft is disclosed herein. More specifically, the present invention utilizes specific data gathered from the golfer's golf swing itself to determine the best performing golf club shaft for this particular golf swing. Even more specifically, the present invention relates to the utilization of infrared motion capturing cameras to record the location data of a golf club shaft throughout a swing. Based on the location data captured, one or more dynamic behavioral characteristics can be calculated to determine one or more preferred shaft characteristics. Using the preferred shaft characteristics, a shaft can be recommended for the golfer having this particular golf swing. The current inventive fitting methodology is preferred to the archaic fitting method of using data gathered from the result orientated ball flight data together with a tedious process of having to try numerous different shafts.

Abstract: A method relating to an improved fitting system for a golf club shaft is disclosed herein. More specifically, the present invention utilizes specific data gathered from the golfer's golf swing itself to determine the best performing golf club shaft for this particular golf swing. Even more specifically, the present invention relates to the utilization of infrared motion capturing cameras to record the location data of a golf club shaft throughout a swing. Based on the location data captured, one or more dynamic behavioral characteristics can be calculated to determine one or more preferred shaft characteristics. Using the preferred shaft characteristics, a shaft can be recommended for the golfer having this particular golf swing. The current inventive fitting methodology is preferred to the archaic fitting method of using data gathered from the result orientated ball flight data together with a tedious process of having to try numerous different shafts.

Abstract: A method relating to an improved fitting system for a golf club shaft is disclosed herein. More specifically, the present invention utilizes specific data gathered from the golfer's golf swing itself to determine the best performing golf club shaft for this particular golf swing. Even more specifically, the present invention relates to the utilization of infrared motion capturing cameras to record the location data of a golf club shaft throughout a swing. Based on the location data captured, one or more dynamic behavioral characteristics can be calculated to determine one or more preferred shaft characteristics. Using the preferred shaft characteristics, a shaft can be recommended for the golfer having this particular golf swing. The current inventive fitting methodology is preferred to the archaic fitting method of using data gathered from the result orientated ball flight data together with a tedious process of having to try numerous different shafts.

Abstract: The subject golf clubs have a shaft and clubhead. The shaft has a tip-end coupled to the clubhead, a butt-end, a reduced-EI portion located adjacent the tip-end, and a remaining portion extending between the butt-end and the reduced-EI portion. The portions are coupled together at an interface. The remaining portion exhibits a respective rate of stiffness reduction as a function of distance from the butt-end. The reduced-EI portion is typically shorter than and has less stiffness than the remaining portion. The reduced-EI portion exhibits a respective rate (which can be zero) of stiffness reduction as a function of distance toward the tip-end. These rates can be similar or different. The interface can exhibit a greater rate in stiffness reduction than the other portions.

Abstract: A method is disclosed for matching a test golfer with a particular golf club selected from a group of golf clubs having a plurality of styles. The method utilizes data set derived in an initial procedure in which the club style preferences for each of a large number of pre-test golfers is recorded and correlated with a set of performance parameters for the golf swings of such pre-test golfers. This data enables the pre-test golfers to be classified into subgroups, in which golfers within the same subgroup generally prefer the same club style and golfers in different subgroups generally prefer different club styles. After this data set has been established, the test golfer takes a golf swing with a golf club, while performance parameters for the swing are measured. Based on the measured performance parameters and the previously established data set, the test golfer is classified according to swing type, and the optimum golf club is then selected from the plurality of styles of golf clubs.

Abstract: A plurality of two or more golf club shafts designed to optimize the performance of a specific shaft with respect to a specific golf swing is disclosed herein. More specifically, the present invention discloses a plurality of two or more golf club shafts wherein a dramatic difference in torque can be achieved by two golf club shafts within the same weight classification regardless of the flex of the shaft. A plurality of golf club shafts in accordance with the present invention may generally a difference in weight-to-torque ratio of greater than about 1.5 and a difference in butt-frequency-to-torque ratio of greater than about 8.0 between any two golf club shafts within the plurality of golf club shafts.

Abstract: A shaft selection assist apparatus according to this invention includes a storage means for storing recommended shaft information indicating a correspondence between measurement parameters obtained upon a test strike with a golf club to which a predetermined reference shaft is attached, and recommended shafts among shafts of a plurality of types, an acquisition means for acquiring the measurement results of the measurement parameters associated with a test strike actually made by a user with the golf club, a selection means for selecting a recommended shaft by referring to the recommended shaft information based on the measurement results acquired by the acquisition means, and an output means for outputting information indicating the recommended shaft selected by the selection means. The recommended shaft information stored in the storage means is information which specifies recommended shafts based on the relationship between the shaft rigidity distribution and the measurement parameters.

Abstract: The present invention relates to a method for determining club parameters for at least one golf club, belonging to a set of golf clubs for a specific golfer, having arbitrary club length Lk,n. The method comprises: selecting club length of a first reference golf club and a second reference club; varying at least one club parameter belong to the group: club weight, club head weight, CG position and weight distribution of the first reference golf club and the second reference golf club; selecting a club parameter value for each selected club parameter. At least one torsional moment PCF, ICF, HCF, GCF is calculated and a relationship is determined as a function of club length. A club length for a first golf club belonging to the set of golf clubs is selected and club parameters for the first golf club is determined based on each determined relationship.

Abstract: The present invention relates to a set of at least three golf clubs having different club length Lk. The golf clubs 14; 20 comprises a shaft 21 with an upper end and a lower end, a grip section 22 on the upper end of the shaft, and a head 23; 30; 40 with a ball-striking surface mounted on the lower end of the shaft. The club length Lk of each golf club decreasing through the set and a value 61, 65, 75; 62, 66, 76; 63,67,77; 64, 68; 78 of at least one torsional moment PCF; HCF; ICF; GCF for each of the at least three golf clubs when swung by a golfer differs from each other. A linear function 71, 72, 73, 74 of club length Lk is based on the values of at least one torsional moment.

Abstract: A shaft selection assist apparatus according to this invention includes a storage means for storing recommended shaft information indicating a correspondence between measurement parameters obtained upon a test strike with a golf club to which a predetermined reference shaft is attached, and recommended shafts among shafts of a plurality of types, an acquisition means for acquiring the measurement results of the measurement parameters associated with a test strike actually made by a user with the golf club, a selection means for selecting a recommended shaft by referring to the recommended shaft information based on the measurement results acquired by the acquisition means, and an output means for outputting information indicating the recommended shaft selected by the selection means. The measurement parameters include the vertical launch angle of a struck ball and the back spin amount on the struck ball.

Abstract: A method can include (i) identifying a reference shaft for an individual based on one or more characteristics of the individual; (ii) receiving shaft feedback information from the individual with respect to a performance of the reference shaft based on an assessment by the individual of one or more reference shaft characteristics of the reference shaft; (iii) executing a shaft comparison between shaft characteristic information of the reference shaft and shaft characteristic information of a plurality of available shafts based on the shaft feedback information of the individual, the shaft characteristic information of the reference shaft comprising information about the one or more reference shaft characteristics; and (iv) identifying one or more recommended shafts from the plurality of available shafts based on the shaft comparison to custom fit the individual. Other examples and related embodiments are disclosed herein.

Abstract: Embodiments of multiple flex shaft systems are disclosed herein. Other examples and related methods are also presented herein.

Abstract: Embodiments of multiple flex shaft systems are disclosed herein. Other examples and related methods are also presented herein.

Abstract: A shaft set includes plural shafts used for wood-type golf clubs each having a length of 40 inches to 48 inches. Among the plural shafts, a shaft used for a longer club has a smaller amount of change ?1 in bending stiffness in a section from 600 mm to 800 mm from a tip of the shaft. Among the clubs using the plural shafts, the amount of change ?1 in bending stiffness decreases at a constant rate in a range of 0.7×103 kgf·mm2/mm·inch to 1.6×103 kgf·mm2/mm·inch per inch increase in club length, and the bending stiffness at a position 800 mm from the tip of the shaft decreases at a constant rate in a range of 0.1×106 kgf·mm2/inch to 0.4×106 kgf·mm2/inch per inch increase in club length.

Abstract: The subject golf clubs have a shaft and clubhead. The shaft has a tip-end coupled to the clubhead, a butt-end, a reduced-EI portion located adjacent the tip-end, and a remaining portion extending between the butt-end and the reduced-EI portion. The portions are coupled together at an interface. The remaining portion exhibits a respective rate of stiffness reduction as a function of distance from the butt-end. The reduced-EI portion is typically shorter than and has less stiffness than the remaining portion. The reduced-EI portion exhibits a respective rate (which can be zero) of stiffness reduction as a function of distance toward the tip-end. These rates can be similar or different. The interface can exhibit a greater rate in stiffness reduction than the other portions.

Abstract: Embodiments of multiple flex shaft systems are disclosed herein. Other examples and related methods are also presented herein.

Abstract: A plurality of two or more golf club shafts designed to optimize the performance of a specific shaft with respect to a specific golf swing is disclosed herein. More specifically, the present invention discloses a plurality of two or more golf club shafts wherein a dramatic difference in torque can be achieved by two golf club shafts within the same weight classification regardless of the flex of the shaft. A plurality of golf club shafts in accordance with the present invention may generally a difference in weight-to-torque ratio of greater than about 1.5 and a difference in butt-frequency-to-torque ratio of greater than about 8.0 between any two golf club shafts within the plurality of golf club shafts.

Abstract: The subject golf clubs have a shaft and clubhead. The shaft has a tip-end coupled to the clubhead, a butt-end, a reduced-EI portion located adjacent the tip-end, and a remaining portion extending between the butt-end and the reduced-EI portion. The portions are coupled together at an interface. The remaining portion exhibits a respective rate of stiffness reduction as a function of distance from the butt-end. The reduced-EI portion is typically shorter than and has less stiffness than the remaining portion. A stiffener insert is inserted into the shaft, such as in the reduced-EI portion, to add stiffness locally. The reduced-EI portion exhibits a respective rate (which can be zero) of stiffness reduction as a function of distance toward the tip-end. These rates can be similar or different. The interface can exhibit a greater rate in stiffness reduction than the other portions. The stiffeners can be user-selectable, from a kit supplied with the club, for example.

Abstract: A device for stiffening a golf club shaft which includes a strip of material configured to engage the exterior of the golf club shaft. The longitudinal axis of the strip may be configured to extend in a direction parallel to a longitudinal axis of the golf club shaft when the strip engages the golf club shaft. The strip may be configured to increase the stiffness of a portion of the golf club shaft when the strip engages the portion of the golf club shaft. The strip may include longitudinal fibers configured to extend in a direction parallel to a longitudinal axis of the golf club shaft when the strip is engaged to the exterior of the golf club shaft. An associated method for fitting a golf club with a shaft stiffening device is also described.

Abstract: A method is disclosed for matching a test golfer with a particular golf club selected from a group of golf clubs having a plurality of styles. The method utilizes data set derived in an initial procedure in which the club style preferences for each of a large number of pre-test golfers is recorded and correlated with a set of performance parameters for the golf swings of such pre-test golfers. This data enables the pre-test golfers to be classified into subgroups, in which golfers within the same subgroup generally prefer the same club style and golfers in different subgroups generally prefer different club styles. After this data set has been established, the test golfer takes a golf swing with a golf club, while performance parameters for the swing are measured. Based on the measured performance parameters and the previously established data set, the test golfer is classified according to swing type, and the optimum golf-club is then selected from the plurality of styles of golf clubs.

Abstract: The method of producing tubular golf club shafts (10) of the same longitudinal stiffness and varying weights by wrapping composite materials on a tapered mandrel (15), or mandrels, having a given taper profile, producing a core (30) of angle-fiber-and-resin material and a shell (31) of longitudinal-fiber-and-resin material, and varying the weight of the cores to vary the shaft weight while maintaining the core size and the shell size the same. This is accomplished by moving the core along a taper profile to compensate for the change in the amount of material, thus maintaining the longitudinal stiffness/bending profile the same in the shafts of greatly varying weight. A representative family of shafts (10) has nominal weights of 55, 65, 75, 85, 95 and 105 grams, with the same stiffness/bending profile.

Abstract: A moveable shaft insert assembly about 13 to 18 inches long weighing less than 50 grams is inserted into a hollow golf dub shaft wherein the depth of insertion of the shaft insert assembly may vary from about 1 to 10 inches. Changing the location of the shaft insert assembly allows a player to change the flex of the shaft and thereby optimize the performance of the club dynamics for that player for that day. The shaft insert is held in place by friction between the shaft and the shaft insert assembly. So shaft flex fitting can be administered by a player with or without coaching, and can be revisited at any time by a simple adjustment. The shaft inserts are useful on all hollow shaft clubs, and can be retrofitted to existing clubs without removing the grip.

Abstract: A shaft set includes plural shafts used for wood-type golf clubs each having a length of 40 inches to 48 inches. Among the plural shafts, a shaft used for a longer club has a smaller amount of change ?1 in bending stiffness in a section from 600 mm to 800 mm from a tip of the shaft. Among the clubs using the plural shafts, the amount of change ?1 in bending stiffness decreases at a constant rate in a range of 0.7×103 kgf·mm2/mm·inch to 1.6×103 kgf·mm2/mm·inch per inch increase in club length, and the bending stiffness at a position 800 mm from the tip of the shaft decreases at a constant rate in a range of 0.1×106 kgf·mm2/inch to 0.4×106 kgf·mm2/inch per inch increase in club length.

Abstract: An improved golf club shaft and corresponding golf club is disclosed. More specifically, a golf club shaft that is capable of minimizing or eliminating swingweight variations within a golf club despite being cut down to various different lengths to accommodate the length and heads of a set of irons is disclosed. The shaft may have an internal wall profile of variable thickness to adjust for various weight and center of gravity variations of a golf club shaft as it is being cut down in length.

Abstract: A golf club shaft having a weight distribution such that the balance point percentage is less than or equal to 44.50%. The weight distribution of the shaft allows for an increase in length and/or club head weight of a golf club while having a reduced impact on the swing weight.

Abstract: The subject golf clubs have a shaft and clubhead. The shaft has a tip-end coupled to the clubhead, a butt-end, a reduced-EI portion located adjacent the tip-end, and a remaining portion extending between the butt-end and the reduced-EI portion. The portions are coupled together at an interface. The remaining portion exhibits a respective rate of stiffness reduction as a function of distance from the butt-end. The reduced-EI portion is typically shorter than and has less stiffness than the remaining portion. A stiffener is coupled to the shaft, such as in the reduced-EI portion, to add stiffness locally. The reduced-EI portion exhibits a respective rate (which can be zero) of stiffness reduction as a function of distance toward the tip-end. These rates can be similar or different. The interface can exhibit a greater rate in stiffness reduction than the other portions. The stiffeners can be user-selectable, from a kit supplied with the club, for example.

Abstract: A vibration reducing golf club includes a club main structure and a plurality of piezoelectric materials. The club main structure includes a club shaft and a ball head and can sustain the mechanical energy resulting from the swing of the club shaft and the collision between the ball head and a golf ball and consequently produces vibration and bending deformation. The piezoelectric materials are connected with conductive wires and adhered to the club shaft. When the club shaft undergoes mechanical deformation, the piezoelectric materials can transform the energy of mechanical deformation into electrical energy, thereby producing a voltage output and then feeding the voltage back to another piezoelectric material, so as to produce a deformation against the vibration direction of the club shaft. Thus, the vibration energy of the club shaft can be consumed. Therefore, the vibration reducing performance can be obtained by reducing the vibration of the club shaft.

Abstract: A golf club comprising a grip, a shaft having a first end and a second end, with the first end of the shaft having the grip disposed upon it, a shaft cap disposed at the second end of the shaft, and a head having a face portion and a hosel portion with the second end of the shaft having the shaft cap disposed on the shaft coupled to the head.

Abstract: A shaft structure with a configurable bending, weight, torque and moment-of-inertia profile is provided for golf clubs, fishing rods, and the like. The shaft structure employs an innovative inner and outer shaft structure. The golfer, in practice, configures the profile of a golf shaft by choosing from a plurality of different inner shaft structures each having a unique bending, weight, moment-of-inertia and torque profile. The inner shaft is securely fastened within the outer shaft. The combination of the inner shaft with the outer shaft results in an advantageous bending, weight, torque and moment-of-inertia profile. The golfer can, at any time and very easily, change the profile of the golf shaft according to their physical, course and weather conditions for any given day.

Abstract: Embodiments of methods, apparatus, and systems to custom fit golf clubs are generally described herein. Other embodiments may be described and claimed.

Abstract: A shaft 6 is formed by a prepreg sheet. The sheet of the shaft 6 includes full length sheets (a2), (a3), (a8) and (a11) provided wholly in a longitudinal direction of the shaft, and partial sheets (a1), (a4), (a5), (a6), (a7), (a9), (a10) and (a12) provided partially in the longitudinal direction of the shaft. The number of the full length sheets is equal to or greater than two. The number of the partial sheets is equal to or greater than four. Each of the partial sheets has an end.

Abstract: A golf club device, more specifically a putter (1), comprising a head (2) and a shaft (3) attached to the head (2), the free end of the shaft (3) possibly being provided with a grip, wherein the moment of mass inertia of the head (2) constitutes less than seventy-nine per cent of the total moment of inertia of the putter (1) when the putter (1) is rotated about an axis of rotation (4), which is perpendicular to the longitudinal axis (7) of the shaft (3) and about one hundred and twenty centimeters from the longitudinal axis (5) of the head (2), and/or wherein the mass of the shaft, including a possible displaceable weight (11), divided by the length of the shaft is at least one hundred and seventy grams per meter of shaft in a shaft which is up to one meter long, and at least one hundred and ninety grams per meter of shaft in a shaft which is longer than one meter.

Abstract: A golf accessory is provided that includes an insert for removably and interchangeably mounting within an interior of a golf club shaft for interchangeably altering a predetermined stiffness or bending moment of the club shaft.

Abstract: A moveable shaft insert assembly about 13 to 18 inches long weighing less than 50 grams is inserted into a hollow golf dub shaft wherein the depth of insertion of the shaft insert assembly may vary from about 1 to 10 inches. Changing the location of the shaft insert assembly allows a player to change the flex of the shaft and thereby optimize the performance of the club dynamics for that player for that day. The shaft insert is held in place by friction between the shaft and the shaft insert assembly. So shaft flex fitting can be administered by a player with or without coaching, and can be revisited at any time by a simple adjustment The shaft inserts are useful on all hollow shaft clubs, and can be retrofitted to existing clubs without removing the grip.

Abstract: A system and method relate to methods for matching a set of golf club shafts for a set of golf clubs. Other embodiments are disclosed herein.

Abstract: A golf shaft includes: a hollow tubular structure; and a gradient structure in which an amount of retained austenite is increased from an approximate center in a thickness direction of the hollow tubular structure to a surface of the hollow tubular structure.

Abstract: This invention provides a wood type golf club including a shaft, a grip at one end of the shaft, and a head at the other end of the shaft, wherein a mass m (g) of the golf club and a length L (cm) from a grip side end of the golf club to a barycentric position of the golf club satisfy m×L=2.55×104 (g·cm) and m×L2=2.322×106 (g·cm2), and a barycentric position of the shaft is at 48.3% a total length of the shaft from a head side end of the shaft.

Abstract: A method is disclosed for matching a test golfer with a particular golf club selected from a group of golf clubs having a plurality of styles. The method utilizes data set derived in an initial procedure in which the club style preferences for each of a large number of pre-test golfers is recorded and correlated with a set of performance parameters for the golf swings of such pre-test golfers. This data enables the pre-test golfers to be classified into subgroups, in which golfers within the same subgroup generally prefer the same club style and golfers in different subgroups generally prefer different club styles. After this data set has been established, the test golfer takes a golf swing with a golf club, while performance parameters for the swing are measured. Based on the measured performance parameters and the previously established data set, the test golfer is classified according to swing type, and the optimum golf-club is then selected from the plurality of styles of golf clubs.