Pianotech

  • 1.  Installing renter back actions

    Registered Piano Technician
    Posted 04-20-2026 14:28

    I frequently replace vintage Steinway back actions with Renner's current iteration. However, we all know that the sostenuto tabs are 3 to 4 mm longer, meaning they extend toward the proximal side, and can create some problems in regulating the sostenuto rod..

    The remedies involve either relocating the pivot pins on the tray or on the blocks, or removing material from the back of the block to move the tray to the distal side. This can create some other problems. It can change the vertical alignment of the damper wire slightly. It can lengthen the contact point of the damper lever increasing the touch weight of the damper lever itself. Other than using somebody else's product, like Tokiwa, I've never really come up with a satisfying solution. I'm wondering if anyone else has.



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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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  • 2.  RE: Installing renter back actions

    Registered Piano Technician
    Posted 04-20-2026 14:31

    Yes, yes yes voice recognition error, the subject line should read "Renner"



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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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  • 3.  RE: Installing renter back actions

    Registered Piano Technician
    Posted 04-20-2026 20:08

    You may be able find a sostenuto rod with a shorter lip.  That can be a problem when installing Steinway's own back action and reusing original

    sostenuto rod in older Steinways.



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    Parker Leigh RPT
    Winchester VA
    (540) 722-3865
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  • 4.  RE: Installing renter back actions

    Registered Piano Technician
    Posted 04-21-2026 21:01

    David Love,

    I'm not being sassy: if it's not too late, procure a Tokiwa kit. I worked with Randy Morton and Tokiwa to acheive the shorter tab.

    David G. Hughes, RPT

    Baltimore Chapter



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    David Hughes RPT
    Vintage Case Parts
    Glyndon MD
    (443) 522-2201
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  • 5.  RE: Installing renter back actions

    Registered Piano Technician
    Posted 04-21-2026 23:27

    Not reading you as sassy at all.  I have used the Tokiwa frequently in the past and had abandoned the Renner back action for that reason.  But, I have a "Steinwas" customer, lol.  However, it's never too late, as far as I'm concerned, and since no one is offering a solution that's probably what I'll do.  

    FEI, (that's "for everyone's information") I have modified the pivot point in several different ways in the past, none of them a perfect solution: cut off the back of the pivot blocks, locate the new pivot pin forward on the tray, plug the old hold in the pivot block and drill a new one behind it.  Three mm's is usually about what's required but each has its own down side not to mention planing off some of the back of the tray so it doesn't bind on the belly rail.  



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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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