Abstract: A method of monitoring wear of a slew bearing system includes steps of assembling a slew bearing system having a first bearing ring and a second bearing ring concentrically positioned relative to each other forming at least upper and lower raceways, a plurality of bearing rollers positioned in each raceway between the first bearing ring and the second bearing ring, and an index system having a first reference connected with the first bearing ring and positioned relative to a second reference on the second bearing ring to provide a measurable distance between the first reference and the second reference, where the measurable distance changes with wear of the slew bearing system; and monitoring a change in the measurable distance between the first reference and the second reference to monitor wear of the slew bearing system.

Abstract: The examples provided describe a golf club having a hollow rail member constructed to provide improved strength while reducing weight. The weight removed by using the hollow rail member may be redistributed to change club performance. Other embodiments may be described and claimed.

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

Abstract: A method of monitoring wear of a slew bearing system includes steps of assembling a slew bearing system having a first bearing ring and a second bearing ring concentrically positioned relative to each other forming at least upper and lower raceways, a plurality of bearing rollers positioned in each raceway between the first bearing ring and the second bearing ring, and an index system having a first reference connected with the first bearing ring and positioned relative to a second reference on the second bearing ring to provide a measurable distance between the first reference and the second reference, where the measurable distance changes with wear of the slew bearing system; and monitoring a change in the measurable distance between the first reference and the second reference to monitor wear of the slew bearing system.

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

Abstract: Embodiments of methods, apparatus, and systems to identify address position of golf club heads are generally described herein. Other embodiments may be described and claimed.

Abstract: A slew bearing system includes a first bearing ring and a second bearing ring concentrically positioned relative to each other forming at least upper and lower raceways there between, a plurality of bearing rollers positioned in each raceway between the first bearing ring and the second bearing ring, a plurality of delivery nozzles capable of delivering an air and oil mixture into the raceways adjacent the upper raceway, passages capable of fluidly communicating the air and oil mixture through the raceways and collecting some oil from the mixture adjacent the lower raceway, seals capable of regulating air flow through the passages and inhibiting outflow of oil from the raceways, and at least one exit port capable of outward flow of air and oil from the raceways adjacent the lower raceway.

Abstract: Embodiments of methods, apparatus, and systems to identify address position of golf club heads are generally described herein. Other embodiments may be described and claimed.

Abstract: The examples provided describe a golf club having a hollow rail member constructed to provide improved strength while reducing weight. The weight removed by using the hollow rail member may be redistributed to change club performance. Other embodiments may be described and claimed.

Abstract: In some embodiments, a golf club head has a body with a front section, a first restrictor of a restrictor mechanism coupled to a first portion of the body, and a weight having a first end coupled to the restrictor mechanism and to the body. The first restrictor has a first stiffness and is non-integral with the weight. Responsive to impact at a first zone of the front section, the first restrictor and the first end of the weight react towards each other, and the first stiffness can resist a deformation of the first restrictor by the first end of the weight. Responsive to impact at a second zone of the front section, the first restrictor and the first end of the weight react away from each other such that the first stiffness is substantially non-involved with first end of the weight. Other examples and related methods are also described herein.

Abstract: In one embodiment, a golf club head includes a body and a restrictor mechanism coupled to a first portion of the body. The restrictor mechanism can have a base coupled to the first portion of the body, and a weight coupled to the base. The restrictor mechanism can be configured to (1) present a first resistance to a first deformation of the base in response to a rotational inertia of the weight relative to a rotation of the golf club head in a first direction, and (2) present a second resistance to a second deformation of the base in response to the rotational inertia of the weight relative to a rotation of the golf club head in a second direction opposite the first direction, where the first resistance is greater than the second resistance. Other examples and related methods are disclosed herein.

Abstract: Embodiments of golf clubs with variable moment of inertia and methods of manufacture thereof are described herein.

Abstract: Embodiments of golf clubs with variable moment of inertia and methods of manufacture thereof are described herein. Other embodiments and related methods are disclosed herein.

Abstract: A slew bearing system includes a first bearing ring and a second bearing ring concentrically positioned relative to each other forming at least upper and lower raceways there between, a plurality of bearing rollers positioned in each raceway between the first bearing ring and the second bearing ring, a plurality of delivery nozzles capable of delivering an air and oil mixture into the raceways adjacent the upper raceway, passages capable of fluidly communicating the air and oil mixture through the raceways and collecting some oil from the mixture adjacent the lower raceway, seals capable of regulating air flow through the passages and inhibiting outflow of oil from the raceways, and at least one exit port capable of outward flow of air and oil from the raceways adjacent the lower raceway.

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.