<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=US-ASCII"> <META content="MSHTML 6.00.2900.2802" name=GENERATOR></HEAD> <BODY id=role_body style="FONT-SIZE: 10pt; COLOR: #000000; FONT-FAMILY: = Arial" bottomMargin=7 leftMargin=7 topMargin=7 rightMargin=7><FONT id=rol= e_document face=Arial color=#000000 size=2> <DIV> <DIV> <FONT size=3> Ok, now this is an interesting discussion.  Admittedly not being a math guy I'm still interested in putting some numbers= on some scales of things I've seen as a bench marks for comparison.</FONT></DIV= > <DIV><FONT size=3>   Let's just take one case I have  first= hand knowledge of.  I rebuilt & 1960 Stwy L 3 years ago that lived in a Fresno area church from the beginning of it's creation to the present so it = has survived wonderfully well.</FONT></DIV> <DIV><FONT size=3>  I was keenly impressed  by the balance = of sound, both in power &  sustain.  I measured the bearing with = a lowell gauge & though I don't have numbers any more to give you my recal= l is that the top capo had over 2 degrees of deflection & the 2nd capo  about 2 or more &  the middle was  1 1/2 degrees tapering down to 1/2  in the bottom & the bass had positive bu= t minimum bearing as it should be with a cantalever.  The crown string stretched across the boards underside revealed lots of residual crown in the= strung condition & more than any other C.C. board I've ever seen up to that time.  All that to say it was in my opinion a text book Steinway/belly  set up both in terms of crown & bearing. &nbsp= ; These are IMO the kinds of observations that  are important to make when we find something that is working really well. </FONT></DIV> <DIV><FONT size=3>  The Stwy L scale as I recall has an average trebl= e tension at 160 lbs per string. It is obvious to see that the majority of the= bearing pressure on the long bridge is increasing  gradually the higher= up the scale we go. </FONT></DIV> <DIV><FONT size=3>  So knowing all of the above, what is the equation= that will calculate an approximate string bearing load under the conditions I describe?</FONT></DIV> <DIV><FONT size=3>  If it's the one- 40th rule for simplicity then&nb= sp; 40 divided into  160 strings  equals 4 pounds per string. Let= 's remove most of the bass strings from this equation for now, since theoretica= lly there isn't much bearing there & we have approx. 160 strings times 4 pou= nds equals 720 lbs. add in say 80 lbs for the bass & it's about 800 tot= al pounds give or take</FONT></DIV> <DIV><FONT size=3>     There is a much more accurate &= amp; glamorous formula for this but I dont' have it at my finger tips.  If t= he scale tension averages 180 lbs per string then we're talking 4 1/2 pounds pe= r string which bumps total bearing load up another 100 ish pounds.</FONT></DIV> <DIV><FONT size=3>  My point in all this is that if we are using stro= nger engineering materials & principles which building better stronger rib structure, which we are<STRONG>, <U><EM>then</EM></U></STRONG><U><EM> surely= our rib crowned & supported boards will survive as well & IMO longer tha= n this example of a C.C Steinway L  I cited above </EM></U></FONT></DIV> <DIV><FONT size=3>   Don't you think?</FONT></DIV> <DIV><FONT size=3>  Dale Erwin</FONT></DIV> <DIV><FONT size=3></FONT> </DIV> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><= FONT style="BACKGROUND-COLOR: transparent" face=Arial color=#000000 size= =2> <DIV dir=ltr><SPAN class=953463523-18022006><FONT face="Comic Sans M= S" color=#000080 size=3>Consider a basic scale of moderately high tension= . Say 40,000 lbs. overall. With this string tension 1,000 lbs of string down for= ce equals 2.5% of scale tension. That is quite a lot considering that most companies are claiming string down force more on the order of 0.5% to 1.5%= of string tension (which would be 200 to 600 lbs). I thought I was setting my= initial string down force pretty high at around 1.0 to 1.5%. I don't like thinking about what I'd be doing to a board loading it up to 2.5%. I can't= imagine it being happy enough at that level to want to stay there.</FONT></SPAN></DIV> <DIV dir=ltr><SPAN class=953463523-18022006><FONT face="Comic Sans M= S" color=#000080 size=3></FONT></SPAN> </DIV> <DIV dir=ltr><SPAN class=953463523-18022006><FONT face="Comic Sans M= S" color=#000080 size=3>Del</FONT></SPAN></DIV></FONT></BLOCKQUOTE></DIV> <DIV></DIV> <DIV> </DIV></FONT></BODY></HTML>