[pianotech] Downbearing on RC&S designs was RE: Steingraeber

[David Love]

That could be (backscale) the issue. But if otherwise there is no difference in tone then what's better, less downbearing or more?


David Love
www.davidlovepianos.com

-----Original Message-----
From: Ron Nossaman <rnossaman at cox.net>
Sender: pianotech-bounces at ptg.org
Date: Wed, 07 Jul 2010 23:06:45 
To: <pianotech at ptg.org>
Reply-To: pianotech at ptg.org
Subject: Re: [pianotech] Downbearing on RC&S designs was RE:  Steingraeber

David Love wrote:
> Which brings up an interesting point about downbearing generally as it
> relates to RC&S designs.  Since the board is designed to have the required
> amount of stiffness without compression and without that added compression
> afforded by downbearing, how much downbearing is appropriate for these
> boards.  I say very little is required and my experience (and experiments)
> would seem to suggest that.  In fact, normal downbearing settings might even
> be detrimental and inhibit the board's up and down movement.  I've come to
> the conclusion that on true RC&S designs only about .5 degree of bearing is
> required in the mid tenor, about .5 - .75 through the treble.  As is typical
> of other designs, 0 - .5 degrees of bearing in the bass.  It seems to be
> much easier to overload these boards than to underload them and traditional
> bearing settings don't seem to bring out the best results.  

That differs considerably from my findings. As long as the 
back scale is long, no tuned rear duplex, the difference 
between 0.3° and 1.5°+ is negligible tonally. These things 
aren't nearly as bearing critical as conventional boards. I've 
set the bass on a couple of pianos at near 0°, and increased 
it to about 1.5° with no apparent penalty. Likewise, I've set 
the tenor and treble at about 0.3° or less (near zero) and 
again at 0.75°-2° with little appreciable change in the sound, 
if any. With a short back scale, I would agree with your 
numbers. But that's the back scale, not the board design.

My take.
Ron N