A golf club counter-weighting system, viable for both original manufacture and after-marketing, features an expandable weight assembly that is easily installed at a designated location within a golf club shaft and expanded via a user tool so as to become reliably secured in place by frictional pressure against the surrounding shaft. In a primary embodiment, the weight assembly is made to be threadedly engagable by the opposite end of a dual-function user tool enabling the weight assembly, when unexpanded, to be conveniently moved axially for initial installation, relocation and/or removal.

A golf club comprises: a golf club shaft extending from its first end to second end in its axis direction; a golf club head attached to the second end of the golf club shaft; a grip attach to the first end of the golf club shaft and having a grip end; and a weight member attached to the golf club shaft. The specific gravity of the weight member is 2.5 or more. The length of the weight member is 20 mm or less. The weight member is disposed in a grip-end portion of the golf club shaft so that a mass distribution in the axis direction of the grip-end portion has a local maximum occurring at a position within the grip-end portion, wherein the grip-end portion is defined as extending from the grip end toward the second end by 40 mm in the axis direction.

A universal swing training apparatus is provided that includes a sports-related implement and a slide mechanism. The implement includes a proximal section and a distal section that are spaced apart to form a gap there-between. The slide mechanism is inserted within this gap and is connected to the upper end of the proximal section and the lower end of the distal section. The slide mechanism includes a rail guide, a plurality of front ball bearings, a plurality of rear ball bearings, and a sliding rail assembly that are cooperatively configured to insure that this upper end and this lower end are coaxial when the sliding rail assembly is situated in a coaxial position on the rail guide, and permit a lateral shift of this lower end relative to this upper end during a swinging of the implement.

A universal swing training apparatus is provided that includes a sports-related implement and a slide mechanism. The implement includes a proximal section and a distal section that are spaced apart to form a gap there-between. The slide mechanism is inserted within this gap and is connected to the upper end of the proximal section and the lower end of the distal section. The slide mechanism includes a rail guide, a plurality of front ball bearings, a plurality of rear ball bearings, and a sliding rail assembly that are cooperatively configured to insure that this upper end and this lower end are coaxial when the sliding rail assembly is situated in a coaxial position on the rail guide, and permit a lateral shift of this lower end relative to this upper end during a swinging of the implement.

A counter-balance grip system for a golf putter that allows for counter-balancing in the three degrees-of-freedom of relevant putter motion. A main balance-weight body is attached to the end of a putter shaft and allows for axial and radial asymmetric internal balance weighting about the putter shaft. The main balance-weight body has an upper balance-weight body and a lower balance-weight body. The lower balance-weight body is used to achieve the asymmetric internal balance weighting in both a single-grip option and a split-grip option; the upper balance-weight body also being used to achieve the asymmetric internal balance weighting in the split-grip option. Either a plurality of internal balancing weights could be used or the main balance-weight body could be machined asymmetrically. Each of the plurality of internal balancing weights has a different length, mass, and/or density, allowing for the dynamic balancing of the putter.

Embodiments of a golf club comprising a club head, a shaft, and features that improve bonding strength between the club head and the shaft are described herein. The club head comprises a hosel that receives a tip end of the shaft. The shaft tip end defines a shaft bonding area and an effective bonding area. The features described herein are designed to increase the effective shaft bonding area with the hosel to improve bonding strength between the club head and the shaft. In some embodiments, the features comprise microgrooves located within the shaft bonding area. The microgrooves can increase the effective bonding area and provide multi-directional resistance to forces applied to the shaft. In some embodiments, the features comprise a ferrule including a weighting feature that replaces a tip weight. In some embodiments, the features comprise a hot melt weight located within the shaft.

One or more embodiments of a training bat including a shaft and a hitting head are disclosed. The shaft includes a handle and hand placement indicators. The shaft includes a first end and a second end. The hitting head is attached to the second end of the shaft. The hitting head includes a flat hitting surface which is substantially flat and a back end opposite the flat hitting surface. The hand placement indicators indicate a position for at least one of the hands of a user on the handle and the hand placement indicators indicate an alignment with the back end of the hitting head.

A trainer for improving an athletic swing includes an elastic band having an anchor end and a handle end, and configured to expand and contract. The trainer further includes a handle coupled to the handle end of the elastic band and configured to be gripped by a user. The trainer further includes a strap coupled to the anchor end of the elastic band and configured to be sandwiched between two objects to anchor the anchor end of the elastic band to at least one of the two objects.

A golf club includes a club shaft having a first end, a second end, and an inner peripheral surface defining an inner space of the club shaft, and a weight piece installed on a first end side of the club shaft. The weight piece includes an insertion portion located in the inner space, and an engagement portion located outside the club shaft to engage the first end. The insertion portion includes a first portion and a second portion. The first portion has an outer diameter smaller than the first inner diameter. The second portion includes a large diameter portion having an outer diameter larger than the first inner diameter in a state before being placed in the club shaft, and at least one rigidity-lowered portion that elastically deforms the second portion so that the outer diameter of the large diameter portion becomes smaller when receiving an external force.

A golf club includes a club shaft having a first end, a second end, and an inner peripheral surface defining an inner space of the club shaft, and a weight piece installed on a first end side of the club shaft. The weight piece includes an insertion portion located in the inner space, and an engagement portion located outside the club shaft to engage the first end. The insertion portion includes a first portion and a second portion. The first portion has an outer diameter smaller than the first inner diameter. The second portion includes a large diameter portion having an outer diameter larger than the first inner diameter in a state before being placed in the club shaft, and at least one rigidity-lowered portion that elastically deforms the second portion so that the outer diameter of the large diameter portion becomes smaller when receiving an external force.