Torque of Finished Clubs
NOTE 12: Several clubmakers have asked if my CS II or III could measure the torque if a finished club. I fooled around with this some time ago and it is possible (and at times very revealing!). The obvious problem is the club will not fit through the hole in my bearing bracket. I built a split bearing bracket to overcome the problem. (If you'd like one they're $35). At first I wondered if the moment of inertia of the club head would affect the results. My assumption was that it wouldn't and I was right. Moment of inertia, which determines torsional frequency, is mass time length squared. The mass of the head is fairly high, 200 grams or more, but the length is very short compared to Club Scout's torsion bar length. Whereas the head had absolutely no effect the grip did. If the grip is left in place it will increase the torque about one degree. A finished club measuring six degrees therefore actually has a five degree shaft. I ran a couple of tests to see the variation with different grips.
|Raw shaft||3.4 degrees|
|Victory||4.1 degrees||0.7 degrees change|
The results are not too surprising. I thought the full cord might have been a little closer to the raw 3.4 number. It was interesting to note that it took a while for the grips to really set up. I tried to measure torque shortly after installing the first grip and it was so spongy I couldn't get the shaft to oscillate at all. In the case of the Victory I took a measurement a couple of hours after I installed it and got a reading of 4.3 degrees or a change of 0.9 degrees. After letting it set up for a day it had dropped to a 0.7 degree change. This seems pretty logical.