A golf club comprises a shaft, a club head, and a connection assembly that allows the shaft to be easily disconnected from the club head. In particular embodiments, a sleeve including a top portion, a middle portion connected to the top portion is described. The middle portion includes a thin wall thickness. A bottom portion is connected to the middle portion including a plurality of engaging surfaces. A central longitudinal axis and an offset angle offset from the central longitudinal axis is described. The offset angle allows a maximum loft change of about 0.5 degrees to about 4.0 degrees. The total weight of the sleeve is less than 9 g.
1. A golf club head comprising:
a body comprising a striking face, a crown, a sole, and a hosel, with the hosel defining a hosel opening, an annular shoulder, and an upper bearing surface, and the sole defining an opening that is in communication with the hosel opening and an internal bearing surface;
an adjustable head-shaft connection system configured to allow the golf club head to be adjustably attachable to a golf club shaft in a plurality of different positions wherein a longitudinal center axis of the hosel is offset from a longitudinal center axis of the shaft, with the adjustable head-shaft connection system having a sleeve with an upper portion engaging the upper bearing surface of the hosel and a threaded lower opening, and a screw extending through the opening in the sole and having a head defining a bearing surface engaging the internal bearing surface of the body and a threaded region engaging the threaded lower opening of the sleeve; and
a hosel insert secured inside the hosel and contacting the annular shoulder, the hosel insert of a height dimension less than a height dimension of the hosel including a rotation prevention portion configured to mate with a rotation prevention portion of the adjustable head-shaft connection system;
wherein the center of gravity of the golf club head has a Z-axis coordinate of less than or equal to about 0 mm.
2. The golf club head of claim 1 , wherein the center of gravity of the golf club head has a Z-axis coordinate of less than or equal to about −1 mm.
3. The golf club head of claim 1 , wherein the center of gravity of the golf club head has a Z-axis coordinate of less than or equal to about −2 mm.
4. The golf club head of claim 1 , further comprising at least two weights attachable to and removable from the body at a plurality of different positions relative to the body.
5. A golf club head comprising:
a body comprising a striking face, a crown, a sole, and a hosel, with the hosel defining a hosel opening, an annular shoulder, and an upper bearing surface, and the sole defining an opening that is in communication with the hosel opening and an internal bearing surface;
an adjustable head-shaft connection system configured to allow the golf club head to be adjustably attachable to a golf club shaft in a plurality of different positions resulting in different combinations of loft angle, face angle, and lie angle, with the adjustable head-shaft connection system having a sleeve with an upper portion engaging the upper bearing surface of the hosel and a threaded lower opening, and a screw extending through the opening in the sole and having a head defining a bearing surface engaging the internal bearing surface of the body and a threaded region engaging the threaded lower opening of the sleeve; and
a hosel insert secured inside the hosel and contacting the annular shoulder, the hosel insert of a height dimension less than a height dimension of the hosel including a rotation prevention portion configured to mate with a rotation prevention portion of the adjustable head-shaft connection system;
wherein a golf club head moment of inertia about the head center of gravity X-axis is between 200 kg·mm 2 and 500 kg·mm 2 .
6. The golf club head of claim 5 , wherein the golf club head moment of inertia about a head center of gravity X-axis is between 200 kg·mm 2 and 300 kg·mm 2 .
7. The golf club head of claim 5 , further comprising at least two weights attachable to and removable from the body at a plurality of different positions relative to the body.
8. A golf club head comprising:
a body comprising a striking face, a crown, a sole, and a hosel, with the hosel defining a hosel opening, an annular shoulder, and an upper bearing surface, and the sole defining an opening that is in communication with the hosel opening and an internal bearing surface;
an adjustable head-shaft connection system configured to allow the golf club head to be adjustably attachable to a golf club shaft in a plurality of different positions wherein a longitudinal center axis of the hosel is offset from a longitudinal center axis of the shaft, with the adjustable head-shaft connection system having a sleeve with an upper portion engaging the upper bearing surface of the hosel and a threaded lower opening, and a screw extending through the opening in the sole and having a head defining a bearing surface engaging the internal bearing surface of the body and a threaded region engaging the threaded lower opening of the sleeve; and
a hosel insert secured inside the hosel and contacting the annular shoulder, the hosel insert of a height dimension less than a height dimension of the hosel including a rotation prevention portion configured to mate with a rotation prevention portion of the adjustable head-shaft connection system;
wherein a golf club head moment of inertia about the head center of gravity Z-axis is between 400 kg·mm 2 and 500 kg·mm 2 .
9. The golf club head of claim 8 , wherein the golf club head moment of inertia about a head center of gravity Z-axis is between 420 kg·mm 2 and 450 kg·mm 2 .
10. The golf club head of claim 8 , further comprising at least two weights attachable to and removable from the body at a plurality of different positions relative to the body.
11. A golf club head comprising:
a body comprising a striking face, a crown, a sole, and a hosel, with the hosel defining a hosel opening, an annular shoulder, and an upper bearing surface, and the sole defining an opening that is in communication with the hosel opening and an internal bearing surface;
an adjustable head-shaft connection system configured to allow the golf club head to be adjustably attachable to a golf club shaft in a plurality of different positions resulting in different combinations of loft angle, face angle, and lie angle, with the adjustable head-shaft connection system having a sleeve with an upper portion engaging the upper bearing surface of the hosel and a threaded lower opening, and a screw extending through the opening in the sole and having a head defining a bearing surface engaging the internal bearing surface of the body and a threaded region engaging the threaded lower opening of the sleeve; and
a hosel insert secured inside the hosel and contacting the annular shoulder, the hosel insert of a height dimension less than a height dimension of the hosel including a rotation prevention portion configured to mate with a rotation prevention portion of the adjustable head-shaft connection system;
wherein the volumetric displacement of the golf club head is greater than 400 cm 3 .
12. The golf club head of claim 11 , wherein the volumetric displacement of the golf club head is between 420 cm 3 and 475 cm 3 .
13. The golf club head of claim 11 , further comprising at least two weights attachable to and removable from the body at a plurality of different positions relative to the body.