GOLF CLUB SET HAVING AN ELASTOMER ELEMENT FOR BALL SPEED CONTROL

1 . A set of iron-type golf club heads, comprising:

a first golf club head comprising:

a first club head body comprising a first back portion and a first striking face;

wherein said first striking face comprises a first front surface configured to strike a golf ball and a first rear surface opposite said first front surface;

wherein said first back portion is spaced from said first rear surface;

a first elastomer element extending from said first back portion to said first rear surface of said first striking face;

a first loft angle;

a first MOI-Y;

a first striking face area; and

a first unsupported face percentage comprising a percentage of said first striking face area not supported by said first elastomer element; and

a second golf club head comprising:

a second club head body comprising a second back portion and a second striking face;

wherein said second striking face comprises a second front surface configured to strike a golf ball and a second rear surface opposite said second front surface;

wherein said second back portion is spaced from said second rear surface;

a second elastomer element extending from said second back portion to said second rear surface of said second striking face;

a second loft angle;

a second striking face area; and

a second unsupported face percentage comprising a percentage of said second striking face area not supported by said second elastomer element;

wherein said first loft angle is less than said second loft angle;

wherein said first unsupported face percentage is greater than said second unsupported face percentage;

wherein said first MOI-Y is lower than said second MOI-Y.

2 . The set of iron-type golf club heads of claim 1 , wherein said first elastomer element is spaced from a first striking face perimeter and wherein said second elastomer element is spaced from a second striking face perimeter.

3 . The set of iron-type golf club heads of claim 1 , wherein said first striking face is substantially constant in thickness and wherein said second striking face is substantially constant in thickness.

4 . The set of iron-type golf club heads of claim 1 , wherein said first striking face is constant in thickness and wherein said second striking face is constant in thickness.

5 . The set of iron-type golf club heads of claim 1 , wherein said first elastomer element displays an elastic modulus of about 1 to about 50 GPa and wherein said second elastomer element displays an elastic modulus of about 1 to about 50 GPa.

6 . The set of iron-type golf club heads of claim 1 , wherein a first area of a first supported region comprises a portion of said first rear surface of said first striking face supported by said first elastomer element and wherein a second area of a second supported region comprises a portion of said second rear surface of said second striking face supported by said second elastomer element, wherein said first area of said first supported region is greater than 60 millimeters 2 and less than 100 millimeters 2 and wherein said second area of said second supported region is greater than 60 millimeters 2 and less than 100 millimeters 2 .

7 . The set of iron-type golf club heads of claim 6 , wherein said first area of said first supported region is greater than 70 millimeters 2 and less than 80 millimeters 2 and wherein said second area of said second supported region is greater than 70 millimeters 2 and less than 80 millimeters 2 .

8 . The set of iron-type golf club heads of claim 1 , wherein said first unsupported face percentage is greater than 90% and less than 99% and wherein said second unsupported face percentage is greater than 90% and less than 99%.

9 . The set of iron-type golf club heads of claim 8 , wherein said first unsupported face percentage is greater than 95% and less than 98% and wherein said second unsupported face percentage is greater than 95% and less than 98%.

10 . A set of iron-type golf club heads, comprising:

a first golf club head comprising:

a first club head body comprising a first back portion and a first striking face;

wherein said first striking face comprises a first front surface configured to strike a golf ball and a first rear surface opposite said first front surface;

wherein said first back portion is spaced from said first rear surface;

a first elastomer element extending from said first back portion to said first rear surface of said first striking face;

a first loft angle;

a first MOI-Y;

a first striking face area; and

a first unsupported face percentage comprising a percentage of said first striking face area not supported by said first elastomer element; and

a second golf club head comprising:

a second club head body comprising a second back portion and a second striking face;

wherein said second striking face comprises a second front surface configured to strike a golf ball and a second rear surface opposite said second front surface;

wherein said second back portion is spaced from said second rear surface;

a second elastomer element extending from said second back portion to said second rear surface of said second striking face;

a second loft angle;

a second striking face area; and

a second unsupported face percentage comprising a percentage of said second striking face area not supported by said second elastomer element;

wherein said first loft angle is greater than or equal to 20 degrees and less than or equal to 24 degrees and said second loft angle is greater than or equal to 28 degrees and less than or equal to 32 degrees;

wherein said first unsupported face percentage is greater than said second unsupported face percentage;

wherein said first MOI-Y is lower than said second MOI-Y.

11 . The set of iron-type golf club heads of claim 10 , wherein said first elastomer element is spaced from a first striking face perimeter and wherein said second elastomer element is spaced from a second striking face perimeter.

12 . The set of iron-type golf club heads of claim 10 , wherein said first striking face is substantially constant in thickness and wherein said second striking face is substantially constant in thickness.

13 . The set of iron-type golf club heads of claim 10 , wherein said first striking face is constant in thickness and wherein said second striking face is constant in thickness.

14 . The set of iron-type golf club heads of claim 10 , wherein said first elastomer element displays an elastic modulus of about 1 to about 50 GPa and wherein said second elastomer element displays an elastic modulus of about 1 to about 50 GPa.

15 . The set of iron-type golf club heads of claim 10 , wherein a first area of a first supported region comprises a portion of said first rear surface of said first striking face supported by said first elastomer element and wherein a second area of a second supported region comprises a portion of said second rear surface of said second striking face supported by said second elastomer element, wherein said first area of said first supported region is greater than 60 millimeters 2 and less than 100 millimeters 2 and wherein said second area of said second supported region is greater than 60 millimeters 2 and less than 100 millimeters 2 .

16 . The set of iron-type golf club heads of claim 15 , wherein said first area of said first supported region is greater than 70 millimeters 2 and less than 80 millimeters 2 and wherein said second area of said second supported region is greater than 70 millimeters 2 and less than 80 millimeters 2 .

17 . The set of iron-type golf club heads of claim 10 , wherein said first unsupported face percentage is greater than 90% and less than 99% and wherein said second unsupported face percentage is greater than 90% and less than 99%.

18 . The set of iron-type golf club heads of claim 17 , wherein said first unsupported face percentage is greater than 95% and less than 98% and wherein said second unsupported face percentage is greater than 95% and less than 98%.

19 . A set of iron-type golf club heads, comprising:

a plurality of golf club heads, each comprising:

a club head body comprising a back portion and a striking face;

wherein said striking face comprises a front surface configured to strike a golf ball and a rear surface opposite said front surface;

wherein said back portion is spaced from said rear surface;

a elastomer element extending from said back portion to said rear surface of said striking face; and

an unsupported face percentage comprising a percentage of said striking face area not supported by said elastomer element;

wherein a loft angle of each of said plurality of golf club heads increases through said set;

wherein an MOI-Y of each of said plurality of golf club heads increases through said set as said loft angle increases through said set;

wherein said unsupported face percentage of each of said plurality of golf club heads decreases through said set as said loft angle increases through said set.

20 . The set of iron-type golf club heads of claim 19 , wherein said plurality of golf club heads comprises at least three golf club heads.