query: bass string design

[John Gunderson]

Dear List Mates
It was pointed out to me that I had attached a "vcard" to my e-mail.
Being a piano tuner, I am a modest guy by nature and would never
knowingly engage in such shameless self-promotion (you'll just have to
take my word on that). What I'm saying is that it was an accident, an
oversight on my behalf.   I beg pardon of all,  it won't happen again...
at least not knowingly.

Now my question.....  I am in the process of restringing a small baby
grand.  I decided to try to rescale it.  I am using as my reference "The
calculating Technician" by David Roberts.  After having spent some time
on the the bass strings I have arrived at a scale that looks pretty good
on paper.  My concerns have to do with the first 4 or 5 strings in the
scale (A0 to E1 or there-abouts).  The original string for A0 measured a
core diameter of .055" and an overall diameter of .230"  and a speaking
length of 42".  This string, according to the calculations, had a
tension ratio of only about 25% of its' breaking point and inharmonicity
of the fourth partial of nearly 20 cents.   Both the hammer contact and
the loudness/sustain factors were poor.  In my scale,  I have lowered
the core diameter of this string to  .051" and raised the overall
diameter to .275".  These changes bring the string to 40% of its'
breaking point and lower the inharmonicity to 11.8 cents (they also
improve the hammer contact and loudness/sustain factors).  But to do
this I am significantly increasing the thickness of the wrapping.  My
question is,  by doing so am I creating other string problems that I am
not anticipating.  Is there an optimum ratio between core diameter to
wrapping diameter.  Is there a point where the wrapping becomes too
heavy for a given core?   Any suggestions/advice will be appreciated.
Thanks...

John Gunderson, Associate Member,  North Jersey Chapter.