Steinway Sostenuto

[David Love]

A stronger sostenuto spring would simply push the blade past the tabs
sooner (as the sustain pedal was released), the noise would still occur. 
The blade, according to reports was not going too far up, evidenced by the
noise being made consistently as the action was pulled incrementally out
until the sostenuto no longer engaged at all.  The sequence of events is:
sostenuto down, blade turns up; sustain pedal goes down, tabs go up under
the blade and the collective spring tension of the tabs holds the blade up
even when the sostenuto is released.  Then when the sustain pedal is
released, the blade slides down the tabs until such a point that it lets
go: KTHUNK.  Would the noise be lessened if the sostenuto were adjusted so
that the blade was engaged by the tabs at the bottom most possible position
of the blade so that when released, the blade would have the least amount
of travel remaining to achieve its rest position?

 David Love
 davidlovepianos@earthlink.net


 > [Original Message]
 > From: <A440A@aol.com>
 > To: <davidlovepianos@earthlink.net>
 > Date: 9/21/2003 6:45:13 PM
 > Subject: Re: Steinway Sostenuto
 >
 > David  writes:
 >
 > << NY Steinway, c 1950.  Hinged sostenuto tabs.  Push down the
sostenuto, push
 > down the sustain pedal, release the sostenuto, release the sustain pedal,
 > KTHUNK.  Normally this occurs on pianos with tabs that are not flexible,
 > but not on with flexible tabs.  Regulation of the sostenuto does not seem
 > to be the problem, though I was not there.  Thoughts? >>
 >
 > Weak sos. spring and or the blade is going too far up and in.  The
cumulative 
 > strength of the tabs is holding the sos. blade in place until you begin 
 > releasing the damper pedal and then the whole sostenuto action is
snapping back to 
 > its rest position.  
 >  ( I think). 
 > Ed Foote RPT 
 > www.uk-piano.org/edfoote/
 > www.uk-piano.org/edfoote/well_tempered_piano.html
 >  <A
HREF="http://artists.mp3s.com/artists/399/six_degrees_of_tonality.html">
 > MP3.com: Six Degrees of Tonality</A>