It could also be that wire--generally--is tougher than it is given credit for. The formula commonly used by scaling and/or rescaling programs is one popularized by Al Sanderson and it is significantly conservative. I'm not sure what wire specifications he based it on but it gives a % of breaking strength that is considerably below that of actual test with both Roslau and Mapes IG wire. Both of these wires will take a 52 to 56 mm speaking length at C-88 without causing much trouble. Obviously, 52 to 54 mm is going to be safer and, like you, I wonder if those extra couple of mm actually translate into any improvement in tone quality. When I say there hasn't been a lot of string breakage I speak, not just for myself, but for the industry generally. I've been involved with enough companies producing pianos with treble sections like this that I would be aware of any significant warranty issues with breaking strings. I've also come in contact with enough technicians of all skill levels around the world that I think I'd be aware if this were an endemic problem. The only specific piano I know of that does have a consistent problem with treble string breakage is the U.S. built Steinway S but with this piano I've measured speaking lengths at C-88 upwards of 58 mm. And I've heard reports of speaking lengths well upwards of 60 mm. That's when technicians call me to ask if they are doing something wrong--they can't tune the things to pitch. New wire helps for a couple of years but that's about it. Yes, strings are going to break. ddf Delwin D Fandrich Piano Design & Fabrication 6939 Foothill Court SW, Olympia, Washington 98512 USA Phone 360.515.0119 Cell 360.388.6525 del at fandrichpiano.com ddfandrich at gmail.com -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of John Delacour Sent: Monday, April 11, 2011 1:12 AM To: pianotech at ptg.org Subject: Re: [pianotech] Breaking bass string At 15:29 -0700 10/04/2011, Delwin D Fandrich wrote: >Over the past 5 to 7 decades there have been quite a few pianos built >with speaking lengths at C-88 between 52 and 54 mm. Quite a few of the >Japanese pianos have come with C-88 speaking lengths of 55 and 56 mm. >Aside from those pianos using excessively dense and massive hammers >there hasn't been a lot of string breakage. It could be that the Japanese wire is stronger at least in these sizes; I have no idea, but surely the only question worth asking is, do these pianos produce a better or a stronger sound in the high treble? Then, you say there hasn't been a lot of string breakage, but you are someone who is aware of the dangers. That can't be said for all tuners. I wonder how much string breakage there is under less careful hands. Another question that I raised off-list with someone is whether the actual tension required to bring these very short strings to pitch is less than the calculated tension. I'd like to test this one day. JD
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