My comment is that most all the suggestions are potentially useful. In Peter and David's circumstances, both will be restringing at least the top two sections, so removal of the capo bar to examine and decide to replace or properly dress it as suggested, is in order. If contacting Bosendorfer/Yamaha, a discussion of their current hardening practices with tech support should be sought, so as to know whether or not a replacement capo is going to be a good choice. If still a really hard capo, then other measures may be needed.
I would certainly be taking the speaking lengths and gauges for those two sections so as to determine if this individual instrument is observing factory specs (as in not having excessively long speaking lengths which could be raising the breaking percentage into danger territory in an already high tension scale).
Peter, I think you and I had a conversation about your heavy handed customer a few months ago. We know that heavily used concert instruments often get restrung after only 8 or 10 years because of the stresses that the performers are putting on the strings. Commonly, string breakage manifests itself in those capo sections. Sounds like
your customer is more or less creating those conditions for himself.
In either case, putting the numbers into string scaling software is in order to establish what the tensions and breaking percentages are.
For Peter's customer, no matter what is decided regarding the Capo bar, Paulello XM wire is in order. It is the strongest piano wire currently made, and my understanding is that, at least in part, this wire was created to address the conditions that piano wire endures in a concert setting. He typically recommends its use most often in the capo sections. Below is a link with a chart for its use in a Steinway D:
https://www.stephenpaulello.com/sites/default/files/paulello/fiches-montage/steinwayden.pdfI have used XM wire in the treble sections on several pianos, usually in the top two gauges. The XM wire sounds better than the standard because it is less stressed, being at a lower breaking percentage
Peter, when you get the piano in your shop, send me the numbers and I will drop them into my Abacus excel spreadsheet and give you the comparisons of XM to standard wire. If you can, drop your numbers into an excel spreadsheet and email them to me. That way i can copy and paste them into Abacus and it is quick and easy. David, I can do the same for you if you like.
XM wire feels stiffer and is more difficult to handle. So making your individual eyes will be more of a pain. I have only made a few of them, usually at the breaks where the third string is a single. Peter, you may want to send Stephen Paulello an email asking him what type of hitch pin loop works best with XM. I think he may be recommending a double euro but I am not entirely sure of that. The XM wire is only available in the 500 gram size, not the larger 2 kg. size, but your usage will more limited.
David, is your customer the original owner? Did you put the Ronsen's on for him? If so, what kind of wear did the prior (original) set have. Your guy may not responsible for sins visited upon the piano.
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Will Truitt
Bristol NH
1-603-934-4882
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Original Message:
Sent: 06-02-2022 07:22
From: Ed Sutton
Subject: Bosendorfer breaking strings
Ed McMorrow has some very clearly articulated ideas about capo shape and hardness, and how they influence string termination and breakage, backed by decades of experience. Perhaps a discussion with him could help.
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Ed Sutton
ed440@me.com
(980) 254-7413
Original Message:
Sent: 06-01-2022 17:37
From: David Love
Subject: Bosendorfer breaking strings
I've taken care of a Bosendorfer 225 for several years now. The piano is notorious for breaking strings in the capo section, top two sections. I have a theory that the capo bar, which is removable in this case, was over hardened. The strings are always breaking at the bar, not at the pin or anywhere else. It's not the hammer or voicing I am certain. Has anyone else ever encountered this and how would you test if the bar has been over hardened short of asking Bosendorfer to send me another one, which I may do. The piano is only about 15 years old.
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David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
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