[golf2much]

The far end speeds up when the radius gets shortened, and vice versa, which could be manipulated to regulate the clubhead speed.

I'm, however, not aware of COAM for clubhead manipulation, I strictly manipulate "lag" (or "club weight" or "shaft bent/stress") in swinging, hitting or snapping.

COAM is not something you CAN manipulate.
COAM is what happens on the way to the ball
Conservation of Energy is what happens at the ball


Part 1. Angular momentum is about what happens on the way to the ball. Whether you hit, swing, push or pull, angular momentum is going to be conserved regardless of what you do. However, the more you can sustain the lag, the more momentum has to be generated on the other side of the equation (i.e. transferred into the ball) for momentum to be conserved. What happens is that you start out with a large center of rotation (big wheel) of the club generally around your left shoulder. As you rotate down the plane and sustain the lag, you are shifting the primary center of rotation of the club to a point in your hands (small wheel), The longer you sustain the lag, the smaller the small wheel, and like the ice skater pulling in her arms, the faster the clubhead mass must travel to conserve angular momentum. Thus, the clubhead arrives at impact with an amount of kinetic energy, which like momentum is conserved.

Part 2. If you think about the impact interval being only a fraction of an inch or so, you can essentially consider this segment of the swing arc as a straight line, and thus, the collision between the ball and the clubhead is about the conservation of energy. The clubhead developed a certain amount of kinetic energy (1/2 m*v^2) during the pre impact interval, and some of that is going to be transferred to the ball through the collision. As Steph mentioned, the collision is elastic and there are some small losses associated with deforming the ball, and the clubface, but these are small. The efficiency of the energy transfer between the clubhead and the ball is related to the purity of contact, meaning mostly contact along the line of compression/direction of flight. Energy is lost to creating spin. Much of the energy is transferred to the ball. So, the simple balance is: (1/2 m1*v1^2 - losses)(clubhead) = 1/2 m2*v2^2.(ball)*

So what this is all about is creating the maximum kinetic energy just prior to impact. Sustaining the lag as long as possible creates the smallest center of rotation, and thus the maximum velocity since the clubhead mass didn't change. Hit, swing, push, pull, these principles don't change.

*Note: this is not rigorously correct since the impact interval is a slight arc, and not a precisely straight line. However it is pretty close.

G2M