A weight adjustable javelin includes an elongated shaft having a leading end and a trailing end. A nose piece includes a conical shape, a nose tip, a nose base, and an internal nose slot defined along a longitudinal axis of the nose piece. The nose base includes an opening leading into the internal nose slot. A tail piece includes a tail tip, a tail base, and an internal tail slot defined along a longitudinal axis of the tail piece. The tail base includes an opening leading into the internal tail slot. The nose base is releasably secured to the leading end of the elongated shaft. The tail base is releasably secured to the trailing end of the elongated shaft. The internal nose slot and the internal tail slot are configured to receive and retain different sized and weighted rods therein.

A small golf swing training tool has the same weight balance as that of a golf club and can easily confirm the orientation of the club face during training A golf swing training tool includes a grasping part made of a rod-shaped member, a weight part made of a plate-like (plate-shaped) member surrounding both ends of the grasping part, and an insertion hole required to allow to grasp the grasping part between the grasping part and the weight part. The grasping part is not arranged at the weight center of the weight part.

In an example embodiment, a golf club shaft is disclosed that comprises: a grip portion and a central shaft. The central shaft comprises a plurality of holes capable of being removably filled by one or more weighted plugs. In various example embodiments, the weighted plugs may be any weight desirable to the golfer, and may be positioned at any location on the shaft where there is a hole to customize the weighting of the golf club. In such embodiments, the weighted plugs may be made of a high density material and may weigh above about 14 grams.

A process for manufacturing a putter with a bi-material shaft is disclosed herein. The putter comprises a putter head, the bi-material shaft, a mass member and a grip. The bi-material shaft comprises a body with a tip end and a butt end. The body comprises a metal section extending from the tip end to a connection point, and a composite section extending from the butt end to the connection point. The mass member is positioned within an opening at the butt end of the shaft. Mass from the shaft is transferred to the club head and the mass member in the butt end of the shaft.

A golf training aid may appear to take the form of a golf club, sometimes without a club head. At a proximal end, or end near the golfer, the training aid may comprise a standard golf grip attached to a carbon fiber cylinder portion, the cylinder portion containing a magnet, with a rubber seat disposed upon the magnet. A metallic ball bearing may be in magnetic attachment the magnet. A plurality of additional ball bearings, smaller than the metallic ball bearing, may be magnetically retained and distal to metallic ball bearing. The ball bearings may be disposed within a laminated polycarbonate tube. A far end or distal end of the training aid may comprise a rubber plug to contain ball bearings that have traveled down the tube, optional weights and a magnetic end cap.

An apparatus for strength training of an athlete in preparation for playing a sport that requires swinging of a bat or other implement comprises an attachment mechanism that is removably attachable to the proximal grip end of the implement, and a weight attachable to the attachment mechanism. A principle axis of inertia of the weight is aligned with a longitudinal axis of the implement, such that added weight does not significantly impact the athlete's use of the bat during practice drills and games. Concentration of the weight near the athlete's hand(s) also reduces risk of injury. In embodiments, additional weights can be added to the apparatus as needed. In embodiments, the apparatus includes a flexible inner member that is pressed against the shaft of the implement by threading thereon of an outer member. A longitudinal spring can be included to create tension between elements of the apparatus.

An apparatus for strength training of an athlete in preparation for playing a sport that requires swinging of a bat or other implement comprises an attachment mechanism that is removably attachable to the proximal grip end of the implement, and a weight attachable to the attachment mechanism. A principle axis of inertia of the weight is aligned with a longitudinal axis of the implement, such that added weight does not significantly impact the athlete's use of the bat during practice drills and games. Concentration of the weight near the athlete's hand(s) also reduces risk of injury. In embodiments, additional weights can be added to the apparatus as needed. In embodiments, the apparatus includes a flexible inner member that is pressed against the shaft of the implement by threading thereon of an outer member. A longitudinal spring can be included to create tension between elements of the apparatus.

A configurable butt for a cue stick comprising a body comprising an elongate chamber having an internal thread and a movable weight coaxially located within the elongate chamber and having an external thread, the movable weight being threadingly coupled to the internal thread of the elongate chamber. An internal shaft extends through the movable weight is adapted to rotate the movable weight within the internally threaded chamber thereby causing the movable weight to move between respective ends of the elongate chamber by virtue of the threaded coupling for adjusting a centre of gravity of the cue stick. An indicator arrangement is coupled to the internal shaft and adapted to provide an indicate of the location of the movable weight within the elongate chamber.

In an example embodiment, a golf club shaft is disclosed that comprises: a grip portion and a central shaft. The central shaft comprises a plurality of holes capable of being removably filled by one or more weighted plugs. In various example embodiments, the weighted plugs may be any weight desirable to the golfer, and may be positioned at any location on the shaft where there is a hole to customize the weighting of the golf club. In such embodiments, the weighted plugs may be made of a high density material and may weigh above about 14 grams.

The invention relates to a method for adjusting a series of golf clubs each comprising a shaft, a head at the proximal end of the shaft and a grip at the distal end of the shaft; said method comprising the following steps: adjusting the mass of the head of each golf club and/or, adjusting the mass of the shaft near the distal end of the shaft, such that each golf club has a substantially identical moment of inertia; then adjusting the mass of the grip of each golf club and/or adjusting the mass of the shaft near the proximal end of the shaft, such that each golf club has a substantially identical swingweight. The invention also relates to a series of golf clubs adjusted using the method according to the invention.