<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: front or back</title></head><body> <blockquote type="cite" cite><x-tab>        </x-tab>This thread brings to mind a related question that I've wondered about for some time. Steinway B's have varied in having either double trichords or trichord and flat in the low tenor section. Current ones have trichord and flat. In the 70's (the vintage of ten I take care of at the university), they used double trichords. Most  of the newer ones I have run across with trichord/flat have one to several that have been changed over to double trichords (I've done it myself on occasion).<br> <x-tab> </x-tab>I wonder what comments other folks might have on this. Was there a good reason to go to trichord/flat? Were double trichords the rule for a pretty long period? (A lot of the older vintage ones I care for have double trichords, but that might have been rebuilder's choice rather than following original design). Can anyone always make trichord/flats work throughout? (Most of the time I can get them to work, but I have fooled around far too long on some and ended up swapping to double trichord in frustration).<br> Regards,<br> Fred Sturm</blockquote> <blockquote type="cite" cite>University of New Mexico</blockquote> <div><br></div> <div>Hi Fred and all,</div> <div><br></div> <div>In my experience the double trichords will cut off more quickly, but they are more prone to 'zipping' than the double/plain combination. However, the combination setup can be a pain unless the thickness of the plains is chosen such that they contact the wire just before the doubles.</div> <div><br></div> <div>So it comes down to a matter of relative damper timing, ie. the timing of the initial contact of the felt with the string<font color="#0000FF"> (I'm referring here to the timing of the two felt pieces, the double and the plain, on a single damper)</font>. The spacing of the unisons will also cause variation in this timing, since the wider the unison spacer, the later will be the contact of the doubles with the wire.</div> <div><br></div> <div>Our practice in recent years has been to use all doubles in the lower tenor, changing to a combination with the plains out the back before changing to all plain felt as we move up the treble. I suspect that the cause of more 'zip' when the doubles are positioned 'out the back' is that the string excursions increase as we move further away from the agraffe. Plain felt is more immune to the 'zip' than are doubles. So if the plain felt contacts first, it takes some energy out of the string before the double comes in for the final 'chop'.</div> <div><br></div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font size="-2" color="#000000"><br> </font><font face="Times New Roman" size="+1" color="#0000FF"><b>OVERS PIANOS - SYDNEY</b></font></div> <div><font color="#000000"><i>    </i></font><font color="#0000FF"><i> Grand Piano Manufacturers</i></font><font color="#000000"><br>      _______________________</font></div> <div><font size="-2" color="#000000"><br> </font><font color="#000000">Web http://overspianos.com.au<br> mailto:ron@overspianos.com.au<br>      _______________________</font></div> </body> </html>