Sustain pedal lift ratio

[Ron Overs]

Hi all,

At various times over the years this topic has been discussed on the 
list. To recap some of my past contributions on this topic, the ratio 
range which seems to satisfy most pianists is somewhere in the range 
of 2.5 - 3.5:1. That is, when the sustain pedal travels 2.5 - 3.5 mm 
for every 1 mm of damper lift.

The 1975 Baldwin SD-10 we rebuilt had an original lift ratio of 
2.0:1. A Yamaha C3 I measured at the time had 2.5:1. While a Grotrian 
275 concert grand had around 5.0:1. When we rebuilt the Grotrian, and 
the Baldwin for the first time, we had complaints about the damper 
lift of both pianos. The Grotrian was deemed too hard to control 
while the complaint of the Baldwin was that the dampers were too 
noisy when the damper pedal was released. We changed the leverage 
ratio of both pianos to 2.5:1 and haven't had a complaint since.

My reason for sending this post today is that yesterday I tuned the 
Grotrian for a recording session, and while there, I got out the 
digital to show how we changed the Grotrian's damper lift ratio. Some 
on the list had expressed an interest in seeing the detail of this 
conversion, but from memory I hadn't gotten around to taking an 
image. Here's the image



I've greyscaled it to take up less space.

The original lift lever was a single piece straight lever. You can 
see where the hinge was located just behind the bass-side lyre 
support strut.

Ron O.
-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
_______________________

Web http://overspianos.com.au
mailto:ron at overspianos.com.au
_______________________
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