David It sounds to me like the bridge top was cut with sloping angle towards the rear as many are for a variety of complex reasons I don't wish to get into now but it does seem plausible to me that you counter readings are canceling each other out and you me have zip bearing in reality. I would suggest pulling a fish line along side the agraffe avoid the damper and see whether the line touches the bridge top before it hits the duplex or NOT. Bubble bearing gauges are great at times but sometimes I doubt there telling me the truth. The line thing will tell you the truth. You may have to remove one damper (or more )so as to gain clearance. Also what does the piano sound like and is it tuning stable. These two items tell a lot of the story regardless of measurements. Dale Erwin ----- Original Message ----- From: "David Skolnik" <skolnik@attglobal.net> To: <pianotech@ptg.org> Sent: Thursday, March 29, 2001 10:54 AM Subject: Downbearing- pos.front/neg.rear > Greetings, > My question specifically addresses, in a new piano, the oft seen > configuration where one has significant (.030") positive front downbearing > with a nearly equally significant amount of negative rear downbearing, > (which should perhaps more accurately be referred to as positive > 'upbearing'. Whatever.) Is there any feeling, among rebuilders, or others > with first-hand experience, that such a configuration either has > attributable tonal effects, or has the potential to introduce some physical > distortion into the board or induce some other type of failure? If this > has been discussed somewhere recently, please direct me. > > Thanks. > > David Skolnik >
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