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Only had my 88 Yamaha U 1 a few months and love it but I am new to all the terminology.
Ran across someone selling an 83 Yamaha U 1 -pristine like mine-advertised all about it being rarely used, beautiful photos but then in one of the photos
he mentioned that he replaced all 88 hammer return spring cords —said it is a common problem with Yamahas.. I have followed this forum for awhile but I just don’t remember reading anything about Yamaha U 1 having common problem of spring cords that disintegrate?
Not sure if I should be worried about mine. How does one identify this issue if piano plays fine?
Thank you
Yes it is a common problem. Have your tuner check them next time you have it tuned.
Very common. Achilles heel common.

Peter Grey Piano Doctor
Replacing the butt spring cord and replacing the white key front are typical repairs for Yamaha pianos.

https://goo.gl/photos/WH7mQwtH2EZ3kCkA6
It is unfortunate that Yamaha uses cotton thread for this. Wool, or something else that holds up better than cotton, is an improvement.

As I have mentioned here before, wrapping the cord around a dowel and cutting it with a knife is difficult, and requires an exact size of the dowel. Much better is to wrap it around a piece of cardboard the width that you would want the cords to be, and then cut the cardboard and cords right down the middle with scissors. That is much easier, and leaves a nice crease where the spring should go.

One of these days, I will get hold of an action like this, and put in butt springs that go from the butt to the back of the damper stop rail, the opposite direction of spring rail butt springs. This would give a much better feel, and be easier to work on than either spring loops or spring rails. I do not understand why nobody has done this. It would be cheaper than either of the other methods.
Originally Posted by Pro-TAC
Replacing the butt spring cord and replacing the white key front are typical repairs for Yamaha pianos.

https://goo.gl/photos/WH7mQwtH2EZ3kCkA6

Very good pictures!
Originally Posted by BDB
It is unfortunate that Yamaha uses cotton thread for this. Wool, or something else that holds up better than cotton, is an improvement.

As I have mentioned here before, wrapping the cord around a dowel and cutting it with a knife is difficult, and requires an exact size of the dowel. Much better is to wrap it around a piece of cardboard the width that you would want the cords to be, and then cut the cardboard and cords right down the middle with scissors. That is much easier, and leaves a nice crease where the spring should go.

One of these days, I will get hold of an action like this, and put in butt springs that go from the butt to the back of the damper stop rail, the opposite direction of spring rail butt springs. This would give a much better feel, and be easier to work on than either spring loops or spring rails. I do not understand why nobody has done this. It would be cheaper than either of the other methods.

Sounds like a good idea!
Had to wait a bit to respond as I enjoyed all the great information. Of course I will have my tech check mine out next month when he comes for the every 6 month tune.
Photos were very good and I’m happy that I have no issue with my Yamaha. ‘Doesn’t seem like it’s a problem except for Yamaha.
I would almost think a job replacing all those cords would be very costly in labor?thank again
I also have a U1 made in Japan from the 70's and had the cord problem.
Has anyone else dealt with the high treble pressure bar cutting strings? I have broke about a dozen. Seems it was too soft, then Yamaha chrome plated it and solved problem? Wouldn't mind taking off the bar and sanding out the string cuts, but wonder how hard that would be and getting it back in properly?

I would like to see this and how it would improve playing. Not crazy about the loop design either.
Originally Posted by BDB
.
One of these days, I will get hold of an action like this, and put in butt springs that go from the butt to the back of the damper stop rail, the opposite direction of spring rail butt springs. This would give a much better feel, and be easier to work on than either spring loops or spring rails. I do not understand why nobody has done this. It would be cheaper than either of the other methods.
Originally Posted by accordeur
Originally Posted by Pro-TAC
Replacing the butt spring cord and replacing the white key front are typical repairs for Yamaha pianos.

https://goo.gl/photos/WH7mQwtH2EZ3kCkA6

Very good pictures!

I agree!

What kind of glue is preferred for this job?

The cord I bought years ago from one of the supply houses, was always a bit thick to fit nicely into the grooves of flanges. I more recently bought on Amazon some 0.3mm braided fishing line, which is extremely strong. It wasn't expensive and it's a 500 metre reel (about a third of a mile) which is enough for a lot of pianos!
Originally Posted by David Boyce
Originally Posted by accordeur
Originally Posted by Pro-TAC
Replacing the butt spring cord and replacing the white key front are typical repairs for Yamaha pianos.

https://goo.gl/photos/WH7mQwtH2EZ3kCkA6

Very good pictures!

I agree!

What kind of glue is preferred for this job?

The cord I bought years ago from one of the supply houses, was always a bit thick to fit nicely into the grooves of flanges. I more recently bought on Amazon some 0.3mm braided fishing line, which is extremely strong. It wasn't expensive and it's a 500 metre reel (about a third of a mile) which is enough for a lot of pianos!

Hi David,

I bought 4.5 meters from Yamaha Canada (the same as in the pictures) for 20$ shipping included. Would you mind posting the link to Amazon of the cord you bought? Have you tried it? I have 2 of these actions to do this month. I plan on using titebond, but I have used PVC-E in the past and it worked fine.

Thanks
Pics are great. Things get more complicated though in the actions th at DO NOT have butt plates.

Peter Grey Piano Doctor
I once had to pull the action out of a piano that had spring cords like this, at the customer's home, which I usually never have to do as a tuner.

I replaced at least two of these cords, but in reality, ALL of the cords needed to be replaced, because they were all disintegrating. And the whole time, I was thinking of what a poor design choice this is, because it seems to me that you would need to replace the cords eventually, no matter what the cords are made of.

frown
FYI, I believe Kawai has the exact same style action however to my knowledge has NEVER had a problem with breakage. They must have done something right.

Peter Grey Piano Doctor
Originally Posted by accordeur
Originally Posted by David Boyce
Originally Posted by accordeur
Originally Posted by Pro-TAC
Replacing the butt spring cord and replacing the white key front are typical repairs for Yamaha pianos.

https://goo.gl/photos/WH7mQwtH2EZ3kCkA6

Very good pictures!

I agree!

What kind of glue is preferred for this job?

The cord I bought years ago from one of the supply houses, was always a bit thick to fit nicely into the grooves of flanges. I more recently bought on Amazon some 0.3mm braided fishing line, which is extremely strong. It wasn't expensive and it's a 500 metre reel (about a third of a mile) which is enough for a lot of pianos!

Hi David,

I bought 4.5 meters from Yamaha Canada (the same as in the pictures) for 20$ shipping included. Would you mind posting the link to Amazon of the cord you bought? Have you tried it? I have 2 of these actions to do this month. I plan on using titebond, but I have used PVC-E in the past and it worked fine.

Thanks

This is not the exact brand I bought (can't see it at the moment) but it's stuff like this:
Braided line
Thanks David!
My point is that this spring cord design is a BAD design choice, due to the cords disintegrating with time.

Why exactly did some piano designers do this? Was there a specific advantage to engineering it this way?
Butt plates with spring cord design is the best in my opinion. Because it is one unit. Independent. The spring is not on a rail shared by neighbours.

No birds eye, just a tight plate. Spring built-in. Useful when re-inserting in the action on a service call because it will hold the screw.

If the only problem is bad quality cord, well that is easily remedied.
It is a materials failure. There are cords that are still good after 100 years. But just as with bridle straps, cotton is not a long-lasting material. I think the old cords were silk.
However, in the context of the "design lifespan" of the unit, it serves the manufacturers purpose very well.

The main problem with the butt plate design is that it REQUIRES regular attention in tightening so that pins don't walk out and thus cause more damage. Maintenance of this feature is often sorely neglected by both owners and "techs".

Peter Grey Piano Doctor
Originally Posted by BDB
It is a materials failure. There are cords that are still good after 100 years. But just as with bridle straps, cotton is not a long-lasting material. I think the old cords were silk.

I bought a length of silk loop cord from Schaff years ago. It was very expensive, I think a metre length, and beautiful to work with, as it wasn't too springy, and was just the right thickness.
Interesting. I'm working on a piano from 1902 where the cords are fine but the springs are disintegrating.
There are organic materials that last longer than metals. I have replace a lot of Steinway repetition springs, because the wippens are fine, but the springs have fatigued.
Just replaced cords on a 1971 Yamaha P2F... will out last the owners...
Hey Les...👍!

Peter Grey Piano Doctor
Wow ! had to come back and thank everyone (since I started this post) and let you know that I have saved all the photos, links, and information in hopes that I’ll never need ever need them. Lol.
I am a semi retired guitarist. Nearly permanently retired from touring cause of pandemic.After 64 years as a guitarist, I touched my first piano at age 72. I have no delusions of grandeur on piano but have fallen for it so passionately that I’m seriously considering selling a few of my guitars to get a U 3 or K 5
I have to be on the guitar still cause it still brings in $ but I feel like I’m cheating on the piano now. I practice piano though minimum 3 hrs a day.
My tech is due next month to tune as part of warranty service and will let him be sure all is good. I managed to take off the front of piano and look at all those parts -certainly look nice and in tact. Looks new for 32 years.
Hopefully I haven’t hurt it much. My teacher has a huge Kawai grand that takes up his whole living room. Initially he said I was very “bangy” but I’ve developed some grace now .
Thanks again.
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