[CAUT] Restringing treble

[Ron Nossaman]

>I have measured
>soundboard drop under tension, and it isn't uncommon to see them drop 
>.050" when the
>piano is chipped to pitch.  Some more (such as the Chickerings with the inner
>rim), some less (Steinways and Baldwins), but there is still a lot of 
>movement
>up and down.
>Regards,
>
>Ed Foote RPT

Not from one broken string, there isn't. That's about 7 lbs of downbearing 
on the bridge, and about 300 lbs of pull on the plate. Also consider the 
directions the movement of plate and bridge respectively take. For example, 
take an arbitrary string of 150mm speaking length, 50mm rear duplex, and 1° 
downbearing. Bridge rise of 0.0245mm (0.001") will change those lengths a 
total of 0.00045+mm (0.000017+"), where you will get a nearly 1:1 
relationship with plate deflection from tension changes and string lengths. 
No contest.

Ron N