Michael has hit upon a good point here. The ability to accelerate a key rapidly is important to a pianist, and what hinders that ability is the presence of too much friction and/or inertia in an action. It is easy to measure friction in an action and to eliminate it, if necessary, but inertia......No one has come up with a good way of measuring it or even begun to figure out how much is appropriate. Touch weight deals only with static weight or balance weight as D. Stanwood says; it only reveals how a piano will feel during pianissimo playing and, to some degree, gives us an idea as to whether or not a key will return sufficiently fast to provide for good repetition. Lets have some talk about inertia from all you techno-type people out there. And in case you are wondering what I'm talking about, have any of you ever encountered an action that was weighed off to reasonable standards but still had a very heavy feel? I can almost guarantee the piano keys were loaded with lead to achieve the "proper" touch weight specs., adding a hell of a lot of inertia in the process. I bet, also, that the piano was suffering from some mechanical advantage problems that resulted in excessive hammer travel per unit of key travel. Believe me, such problems as indicated above can produce real unwieldy pianos. What do you think??? PS -- Heavy hammers add a lot of inertia, also. Ken Sloane, Oberlin Conservatory
This PTG archive page provided courtesy of Moy Piano Service, LLC