Greg, If the crown was created by being deformed for many years we would see all piano makes with this feature. If this were so they all would have crowned bridges. But clearly some makes have crown and others don't. Maple bridges are quite stiff and I doubt that the crown I see could be caused by the ribs pushing up. There is after all the force pushing down from the string bearing. I can't say if every single piano from these sources had the same amount of crown to begin with or whether sometimes they would leave it out but I can say with reasonable certainty that practically every one I have removed from a soundboad had at least some crown. It is much more obvious on the larger pianos than the smaller ones. I have taken Model D bridges off that show a full 3/4" or more of crown under the killer octave after fifty years. This same piano probably had 1/8" of crown left on the longest ribs. I will try to get to your other question later. I am tiered from all the back and forth with Ron's postings. John Hartman RPT John Hartman Pianos [link redacted at request of site owner - Jul 25, 2015] Rebuilding Steinway and Mason & Hamlin Grand Pianos Since 1979 Piano Technicians Journal Journal Illustrator/Contributing Editor Greg Newell wrote: > John, > I think I see your line of thought here. You have exclaimed that > you rebuild with the same techniques you have found on the piano > originally. Did I paraphrase that correctly? If so how can you tell if > the original bridge was intended to be crowned from the factory or if it > simply took on it's curvature from being mated to the soundboard panel > for 'lo these many years?
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