Sohmer Bridge Agraffes

[Delwin D Fandrich]

----- Original Message -----
From: Larry J. Messerly <prescottpiano@juno.com>
To: <pianotech@ptg.org>
Sent: February 09, 2000 6:15 PM
Subject: Sohmer Bridge Agraffes


>
> Why do these agraffes cause false beats and not the ones on the harp?  Is
> it the regidity of the harp, the angle of up-bearing of the string going
> to the tuning pin?  It was agreed upon that it is not because the agraffe
> is loose in the wood.

Good question.  A couple of years ago we replaced the soundboard in a rather
large Sohmer using one of these bridges.  We retained the original bridge.
(Check the archives if you're interested.)  One of the remarkable things
about the completed piano was its general lack of false beats through the
upper tenor/treble.



> My thought was to add side bearing to the string as it goes through the
> bridge agraffe by inserting bridge pins in the center of the bridge to
> pull the string to the side of the hole in the agraffe.  (Increasing the
> height of the string passing over the bridge behind one of these agraffes
> would probably not be a good idea.)
>
> Suggestions?

I think I would check other aspects of the design before messing with the
bridge agraffes or assigning all of the blame to them.  In our experience
this bridge worked quite well.  There was no bridge roll or distortion and
the original bridge was in generally good condition.  Remarkable,
considering the extremely high tension of the original scaling -- well
upwards of 60,000 lbs (27,240 kg-force).

Good luck.

Del