Size and COR

Question
I saw a response that you made to an individual that a smaller driver will be shorter distance wise as the face is not as thin.  I'm wondering where you got this information.  COR or contact time as they now use is set by USGA and club heads regardless of size come right to the maximum allowable limits.  If your rationalization is that the smaller heads have about the same gram weight so the weight has to be somewhere would seem logical.  However, most of the weight that is in the smaller heads that creates the same gram weight as a larger head is in the hosel.  If you notice, smaller drivers has larger hosels.  This not only true with drivers but with irons.

Answer
Hi J,

I can't recall the specific research paper that I read on this topic.

A larger driver face can be designed to maximize COR by making different parts of the face thin and some others thicker.

With a smaller face, this is much more difficult. For instance, it the face was only 5 square centimetres, is would be very difficult to get much "spring like effect."

As far as I know, small face woods such as 3, 4 and 5s, do not have maximum COR. Do you know otherwise? Have you read research results to this end?

Feel free to reply to my email, [email protected]

Best regards,
Ken Tannar