[CAUT] Hardness of termination vs string breakage (was Re: restrung D)

[RicB]

I again Fred

I agree wholeheartedly concerning strings rising up the bridge pins due 
to bridge expansion. This idea has been around for a 100 years at least 
and is one of the major reasons used to explain strings climbing bridge 
pins. That Nossaman accepts and forwards the bridge expansion bit has 
always struck me as being rather at odds with his contrasting claim that 
strings <<do not climb>> pins.... but that is another subject matter.  
Point here is that I have only rarely seen strings break at the bridge 
pins as well.  But then we have not seen the employment of pins which 
are significantly harder then the strings themselves.  It does strike me 
that if anything close to the kind of wear on present pins were 
transfered to the string material... we'd have a problem.  But I guess 
only the use of such pins for some years would tell for sure.  We do 
tend to toss around a lot of bits and pieces of what we know of the 
physics involved in our musings and forget that musings much of this 
remains, and nothing more... which is a good thing IMB as far as it goes.

As for capo hardening.  I'm glad you bring it into question as it forces 
me to admit that here again... I dont really <<know>> and I agree that 
lack of  <<knowledge>> in the face of what is popularly claimed as such 
in this regard is indeed a  "bit of cognitive dissonance" as you put it.

Cheers
RicB

    Hi Ric,
        I accept Ron Nossaman's analysis: bridge expansion and contraction
    pushing the string up and down the bridge pin are the main factors
    in bridge
    pin wear. Considerably more friction (between pin and string) is
    involved in
    this motion than in strings being drawn through/past the pins in
    tuning. I
    also accept the notion that there is simply too much friction at the
    bridge
    for wire to slip past both pins and bridge top except when there is
    a very
    large change in pitch (in the 100 cent range), based on experience,
    experimentation, and the experiments and analysis of others. Now I
    guess it
    is possible that friction between string and pin caused by bridge
    rise and
    fall would cause wear to the string, if the pin were harder than the
    string.
    Would it be significant, and enough to cause weakening leading to
    breakage?
    I'm skeptical, but I guess I allow it is possible. It wouldn't keep
    me up
    nights <G>. I have never seen a string break at a bridge pin, unless
    it was
    water/rust related.
        About the question of capo hardening, I am merely asking people
    to set
    aside "what seems reasonable" and "what one heard somewhere" and take a
    fresh look. Is there really compelling evidence out there, one way
    or the
    other? Is the conceptual model really convincing? The conceptual model
    doesn't convince me, unless someone has a different one to offer,
    and I am
    not convinced by what experimental evidence I have been able to
    gather from
    people with experience.
        I have never fooled with capo hardening, nor has anyone in my
    neck of
    the woods, so I have no personal experience to draw on. And no
    particular
    axe to grind, either. It's just an annoying bit of cognitive
    dissonance I'd
    like to see cleared up, or at least made a bit clearer.
    Regards,
    Fred Sturm
    University of New Mexico
    --