<HTML>In a message dated 2/2/2003 8:37:36 PM Pacific Standar= d Time, Erwinspiano writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj: Re: Bearing difference= on different soundboards Date: 2/2/2003 8:37:36 PM Pacific Standard Time From: <A HREF="mailto:Erwinspiano">Erwinspiano</A> To: <A HREF="mailto:oleg-i@wanadoo.fr">oleg-i@wanadoo.fr</A> In a message dated 2/2/2003 3:50:34 PM Pacific Standard Time, oleg-i@wanadoo= .fr writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj: RE: Bearing difference= on different soundboards Date: 2/2/2003 3:50:34 PM Pacific Standard Time From: <A HREF="mailto:oleg-i@wanadoo.fr">oleg-i@wanadoo.fr</A> To: <A HREF="mailto:Erwinspiano@aol.com">Erwinspiano@aol.com</A> Sent from the Internet I understand that if we see,= for instance 1/4 inch crown from below the board, that does not really mean= that having 1/4 distance bearing at the string rest will absorb the whole c= rown, it depends of the back string length vs. the speaking length. <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Isaac--Even with 1/4 inch crown The board could actuall= y be pushed down to flat under the situation you describe, if the board is r= eally weak. With the strings off try pushing down on a board with your hands= and watch how much it moves so that you can get a feel for how stiff it wil= l be. If it has some strength  it will have resistence that  will = not permit the 1/4 inch distance bearing to push it flat. . Dale, I mean : If you have  1/4' crown= , and you have 1/4" height difference at the rear stri= ng rest, even if the string became straight under tension, (defluxion absorb= ed) the board will not deflect 1/4", but less, because the 1/4" 'leverage' i= s divided by the string's length, anyway that was my idea and that make sens= e.</BLOCKQUOTE> </BLOCKQUOTE> >>If the string actually became straight the board would be flat&n= bsp; but if the board has resistence it won't allow the string to become com= pletly flat. Does that make sense. The problem is old CC boards most often d= o not have much resistence or crown. <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"><BLOCKQUOTE TYPE=CITE style= ="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PAD= DING-LEFT: 5px">So the stati= c method explained by Nick Gravagne is OK, showing how to compute a maximum = amount of down bearing , or distance bearing, in regard of the existing crow= n (taken rib by rib) and still having some security in regard of the possibl= e collapse of the board.</BLOCKQUOTE> </BLOCKQUOTE> >>  Once again No it doesn't work exactly.  His method takes= the rear string length and multiplies by .026.  For example 4 inches t= imes .026 equals .104  distance bearing. This gives a 1 &1/2 degree= angle of deflection on a 60ft crowned board. And These figures only work on= a new fully crowned board.       Now here is the part I'm having trouble making clear to y= ou. First I've done it his way and it doesn't work. He himself has modified = his procedure but hasn't revised the article. What will happen if you do it = as Nick has written is that as  the tenor is strung first the board is = compressing so that when you reach the beginning of the first capo section t= he nice distance bearing you thought you had calculated is disappeared as th= e sounbboard sunk under load . You can check it with a bearing string. So pr= e stressing compensates for this. Read the article I suggested you'll be enl= ightened.   Pre-stressing makes so much sense you'll be amazed regards Dale <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"><BLOCKQUOTE TYPE=CITE style= ="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PAD= DING-LEFT: 5px"> </BLOCKQUOTE> </BLOCKQUOTE> </BLOCKQUOTE> </HTML>