<HTML>In a message dated 12/20/2002 8:05:48 AM Pacific Standard Time, davidlovepianos@earthlink.net writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj: Setting downbearing Date: 12/20/2002 8:05:48 AM Pacific Standard Time From: <A HREF="mailto:davidlovepianos@earthlink.net">davidlovepianos@earthlink.net</A> Reply-to: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A> To: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A> Sent from the Internet I've been reviewing some articles on setting downbearing and there seem to be a few different schools of thought.  It seems (and reasonably so) that choices about the amount of bearing will depend on the board and the amount of crown.  But what are the general guidelines as to how much, under what circumstances might you vary that amount, and in which direction, and what are people's general procedures including prestressing vs not prestressing the board?   Thanks in advance.   David </BLOCKQUOTE>                  Hi David I         I'm to weary to address this completely but yes the net bearing should be set according to crown and even if the board is flat but yet miraculously sounds legitimate at least some mild amount is needed IMO. I.E. on a S7S compression crowned board I doubt for example that there crown either by accident or design exceded a 70 or 80 ft radius in the largest part of there bellys yet we do find generous amounts of bearing in many of these pianos that have aged well. Also Even if the crown spec they were aiming for was a 60ft crown realize that on ribs shorter than 24 inches that less than 2.5 mm of crown woul be measurable on any given day prior to string that is. In fact the top two treble ribs would show virtually no measurable crown at a 60 ft. radius.   All this to say there is no clear cut answer but I'll bet some opinions could be had.     More later----Regards Dale            Regards</HTML>