In a message dated 5/27/2009 4:46:48 P.M. Central Daylight Time, rnossaman at cox.net writes: PAULREVENKOJONES at aol.com wrote: > In balance, I agree, but in reality, it makes no difference. The > discovery of the overborne backscale was the primary problem. The > lessening of the back bearing and the net lessening of overall bearing > are in this instance just differing perspectives on the bearing > condition as a whole. The front bearing condition may marginally change > with the change in back bearing and both components need to be watched > as changes are made. Has this been your experience? My experience has been that, short of rather dramatic negative front bearing, the balance of bearing front and back has very little affect on tone. Net bearing changes are by far the more significant tonally. I think that that is a very compelling observation, although I have had two occasions in which altering the back bearing (and net therefore) created significant tonal improvement. In both cases it involved removing the felt on the bearing bar that had been placed there by a technician in a restringing. The bearing conditions were acceptable front bearing (0.50 degrees) and almost zero back bearing. Removing the felt gave me close to 0.50 degrees back bearing and a net of about 1.0 degree. It is not so much altering the back bearing (net bearing therefore) but being able to diagnose a condition that is alterable to the benefit of the tone. That's my only point. I try to come close to balancing front and back bearing when I set a piano up, just as a place to start, but I've found plenty of pianos with anywhere from slightly negative, to excessive bearing either front or rear that didn't seem to adversely affect tone. In every case I can remember where I've checked bearing and crown in response to tonal complaints, net bearing against crown answered the necessary questions. I couldn't agree more, and my experience mirrors yours. No, I just remembered one. A newish grand, under warranty, nasty WHANG in the high tenor, next to the plate strut, on a hard blow. Local techs baffled, so they gave me a shot. After whanging around for a while, I found slight positive crown there, and slight positive net bearing. The problem was a combination of front bridge pins drilled too near vertical, only about a 5° offset, and slightly negative front bearing. The strike pulse was making the string move on the bridge pin. Had the pin been at a 15° or more angle with a 10° or so offset, it wouldn't have been noticeable, as I've seen these bearing conditions in pianos that didn't make noises. Nice diagnostics! Ron N **************We found the real ‘Hotel California’ and the ‘Seinfeld’ diner. What will you find? Explore WhereItsAt.com. (http://www.whereitsat.com/?ncid=emlwenew00000004) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090528/6054e235/attachment-0001.htm>
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