Flexy S&S D Keys

[David Love]

The issue has to do with what's been termed "action saturation".  As one
plays up the dynamic ladder with ever increasing force the key flexes more
and more.  At a certain point, before the pianist has reached the top of the
dynamic range, the excessive flexing in the keys prevents a harder blow from
accelerating the hammer any faster.  The upper level of fortissimo is
therefore limited by the flexibility of the key.  You can imagine if the key
were made of a very flexible material that on a blow of any force you would
just push the key though its dip range before the back end of the key even
started moving.  That's the basic idea, though I'm sure others can explain
it better.  

The reason it happens on D's is because of the long key length and on
Steinways in particular because the height of the key has been reduced
somewhat to accommodate the accelerated action bearing which is considerably
thicker than the thin felt punchings previously used.  The reduction in
height makes the key that much more flexible.   

The amount of flex is deemed too much when the point of action saturation is
reached at too low a level in the upper end of the dynamic range.  

David Love
davidlovepianos at comcast.net 
www.davidlovepianos.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Richard Brekne
Sent: Saturday, May 03, 2008 7:03 AM
To: pianotech at ptg.org
Subject: Flexy S&S D Keys


    Hey: I'd like to know how much flex is too much and why just S&S D's?

    Gerald McCleskey RPT