Question

1.36K viewsAugust 8, 2016

Michael-CCLGolf 186 August 8, 2016 0 Comments

Britt or Jim,

Since the first 2 factors that affect launch are loft and vertical center of gravity, and in that order, how can loft be adjusted to make the launch of 2 different heads to be similar?

The TE Forged head has a VCOG of .675. The MMB-17 has a VCOG of .741. The KE4 Tour+ has a VCOG of .785.

Comparing the stock loft angles of the same three are 35, 35, 33 respectively.

In light of this, with other factors equal, I’d expect the KE4 Tour+ to launch lower with 2* less loft and a higher VCOG. Pretty obvious. Now comparing the other 2: same loft but much different VCOG.

Now for the big question: how much would I have to adjust (strengthen) the loft of the TE Forged to produce a similar launch to the MMB-17 (with the much higher VCOG)? Is there a simple formula to figure that?

(I realize changing the loft will also change the bounce.)

Thanks! Michael

1 Answer

Answer 1 · 2016-08-09T14:23:16+00:00

First, .066 difference in the vertical cg’s of the TE and MMB is not that big of a difference. As you said, loft will have a much greater affect on trajectory than the vertical cg and it would be almost impossible to determine how how much such a small difference in the vertical cg could have on trajectory. Ralph describes in the MPF book on irons that being able to drive the cg of the clubhead below that of the ball is a key element in producing “solid” shots. That is the most important element of the vertical cg. In trying to calculate the affect of .001, .025, .066 etc. on the trajectory of the shot, the isolation of that one element would require some pretty sophisticated equipment and even then I am not sure it could be done. That being said, if we look at history and what the loft of a 5 iron was in the late 60’s (31 degrees) and compare it to one that has say 28 degrees, and say the 31 degree has a vertical cg of .836 and the 28 degree has an actual vertical cg of .756″, and we assume the trajectory and distance of these two clubs is exactly the same, then we can say that .080″ is equivalent to 3 degrees of loft. In doing this we would have to assume every strike was precisely the same, with precisely the same attack angle, struck in exactly the same spot on the club face, at exactly the same speed, using the same exact ball, etc. It is important to note the amount of change varies at different clubhead speeds. Also realize that when you change the loft you change the not only the bounce, but the vertical cg location as well. It may not be much, but it does change. The best way to know the affect for any individual would be to test, change, test again and compare the data.

Britt Lindsey