Originally Posted by jmnk
Could you elaborate on what you mean by that? Perhaps a drawing would help.....
The two racquets have the same swingweight when measured in the plane normal to the stringbed, but if you mounted them in an RDC machine with the handle rotated 90 degrees to measure the swingweight in the plane of the stringbed, the racquet with higher twistweight would measure higher swingweight than the other because the added weight on the sides of the hoop is farther from the pivot point than if the weight were placed in the center of the stringbed.
Your actual swing occurs in a plane that is neither completely normal nor completely parallel to the stringbed, so the twistweight contributes to the "effective" swingweight, which is always slightly higher than the measured swingweight. In most cases, the difference between measured swingweight and "effective" swingweight is consistent enough that it is not worth worrying about the difference. But the example presented (with 2 frames of equal mass, balance, and measured SW, but different mass distributions) is a case where the difference does come into play.
I have to go catch a plane this morning, so I'll leave a drawing to someone else.