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Can any one help me on this? I recently bought a 1983 made used Yamaha upright piano W102B in a great condition. A piano technician who helped me inspected it, did the key regulation, tunning, also took out the whole action part and brought to his workshop to blow the dust. However after all done, I noticed all the keys started to have a bouncing noise after press. After each press, the shank bounce on the rest rail and make a noticeable noise. And the techinican said it is like this, he can't do anything about it.

Please check the video below. You need to turn on the full volumn in order to hear the noise.

https://photos.app.goo.gl/KsyZxGxuaBWkuBLS9

Can anyone advice if there is any way to fix the problem or reduce the above bouncing noise? Thanks a lot!

Lyrabbit,

The noise is probably a combination of hammer rail, capstan contact, and keybed cloth all together. It may get slightly better by regulating the capstans such that the hammershank stand barely proud ofvthe rest rail. This is the way it is done at the factory. Also, if the piano is once hard floor, it will tend to amplify ANY impact noises in the piano. You might try putting it on a thick cushy rig and see if that improves anything.

Nonetheless, there is a certain amount of action noise no matter what in all pianos. The front board usually reduces your perception of it.

Pwg

hi, lyrabbit
I clearly hear that this sound comes from a key returning to a static position. I advise you to try under one key to putting a thin felt piece 2-3 mm
good luck,

Thank you very much "Pwg" for your kind reply. I was desperate to get some suggestions from here.

The loud bouncing noise happened after the regulation, blow the action part and tunning were done. And it happened on all the keys. I know every piano has some action noise, but not as loud as my piano currently did. Though I didn't hear it when my son played a whole piece smoothly. It is very noticeable and annoying when playing the keys one by one.

I suspect the regulation made it happen. The technician screwed on the middle part of the action one by one. I didn't know exactly what he did. I also found the key touch felt looser vertically (up and down) after the work. Though he said he tightened all the keys from wobbling right and left.

The technician I used though the 1st time, has a great background and tunned the piano for a list of big-name pianists in the world for their concert. So it made me so puzzled and painful with the feeling that my piano was getting worse.

Thank you Maximilyan. May I know which felt do you refer to. Sorry, I am new to piano, I google the part name of piano actions. And there is hammer butt felt, backcheck felg, hammer rail cloth, etc. But the noise only happen after the regulation and tunning. It was not noticeable before. So I think it shouldn't be anything need to be replaced. But I'd still like to try, could you tell me more specifically which felt? Thank you very much!

this is the item of for piano that is located under all 88 keys. It is called "Back rail cloth " http://www.pianofortesupply.com/wp-content/uploads/2011/12/DSC00902.B.jpg
Usually on Soviet upright pianos, from a long operation, this strip of fabric (felt) turned into hard condition. I usually remove 88 keys the piano from out. I use a toothbrush there. Unnecessary additional sound leaves after this operation. If not, then I laying along the entire length of the new cloth over the old fabric cloth 1-2mm. I do not glue new fabric, only 2 screws fix the edges there.
If you have extra sounds coming from a few keys, then perhaps the culprit is moth.
try to put the fabric under the key and the sound will surely go away !, I'm sure. You can do this experiment by yourself I suppose. It won’t harm your piano, I guess.
good luck

Yamaha hammer rail cloth is originally very fluffy .
It does not become easily hard .
I guess the balance hole and bushing may be loose or lost motion is too much.　　　(^。^)

it's 33 years and it may be hard condition

I feel that so it's sound came from point position of a key Back rail cloth (video)

All I have to play at the moment is a Steinway upright with the panels on and lid down,
it makes about the same amount of "bounce" noise as yours.
To be honest I don't hear it normally . Push forward on the hammer rest rail slightly, then try again.
Different?

That noise can be caused by the bridle strap suddenly snapping tight when the whippen falls. You can test this by temporarily unhooking the strap on a single note.

Thanks everyone for your kind comment. I will update how it is going on soon. By the way, the video of the noise in on the top post, and I put it here again. If you use an earpiece, you will hear the noise very clearly.

Video of the bouncing noise (pls use a headset or earpiece to hear it): https://photos.app.goo.gl/KsyZxGxuaBWkuBLS9

it's grand piano simple, so upright has the hammer rest rail too.


May be it's so. It was no regulation wooding plank (the hammer rest rail )here

I hear in your video now and I'm thinks that WOOD noise has came from (wood frame of keys) downly point.
I would really advise you to try experimenting with the bottom plywood panel (frame of keys).
Try start to press it's of and release it while you pressing a key. Perhaps the reason is precisely in it's poor fixation of screws

Have technician replaced all hammers with new?
I guess these hammers are not original.
That may be my fault but I can also hear noise like poor adhesion.
Have technician replaced balance bushing, punching and back rail cloth?

It is possible the "law of unintended consequences" has come into play here. As the OP stated, all components were tightened in the process of reconditioning. It is conceivable that the "bounce noise" was there before, but was being somewhat absorbed by slightly loose action parts. Now that everything is tight (as it should be) all the impact noise is being transferred to the specific spots where parts come to rest, therefore concentrating the velocity in those areas.

This is just an educated guess, but based on the fact that the noise was "perceived" only after the action was worked on. It is not humanly possible (imperfect as we are) to be able to predict accurately EVERYTHING (even though we do the right thing). Stuff happens. The key now would be to figure out a,way to mitigate it acceptably. Replacement of felts (as Pro-TAC suggested) may be what is needed. Remember, this instrument has almost 40 years of usage on it. Things compress and get denser over time and pressure. That's just life.

Pwg

Needling the back rest felt could mitigate the noise. Also, the lost motion should be reduced.

May I know what the lost motion mean? Pro-TAC also mentioned it, but I didn't get it. Thank you for explaining further.

Thank you everyone for your contribution and trying to help here. I'd like to give you some update on the progress here. My technician came yesterday and tried to resolve the problem. I also showed him all of the comments here. He believed the noise is because of the compressed hammer rail cloth, as most of the sound came directly from the hammer shank bouncing on the rail cloth. He took out the rail, using a thin blade to life up the underneath of the cloth as the cloth was originally glued on the rail, also stick some hole to make it more fluffy. It solved most of the problems! The action sound from low end to middle part is much quiet now, within the normal range. But on the high end, from the 2nd A note from middle C onwards still have the noticeable noise. probably a bit better than before though. I feel the noise not only from the shank rest rail, some down part also contribute to it. But anyway, it was much improved and bearable now. We will change the rail cloth next time.

Thanks all again!