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 --
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