Backrail felt: how thick can you go?

[bourniplus]

Hey everyone, first, happy new year to all! I just received my MkI refurb kit from Vintage Vibe. While the Rhodes is apart I'm thinking of replacing the original backrail felt with new thicker one - or maybe a combination of red felt and green felt on top - in order to quiet the action.
Now, if I bring it up to a height similar to that of most acoustic pianos, that will reduce keydip and hammer travel significantly. So, I would have to shim the action rail accordingly, and the harp as well. Is there any other major problem I'm not thinking of? Am I going down a rabbit hole??

[pianotuner steveo]

Yes, you are going down a rabbit hole. Never put 2 layers of felt here. Reducing the dip that much will make the action feel choked/heavy, then raising the rail creates more issues that need to be dealt with.(key height, hammer stroke, escapement,damper issues)
Just use ONE layer of back rail cloth. The secret to reducing the noise is to NOT PUT GLUE directly under the part where the keysticks actually touch the felt. Only put glue (lengthwise,across the keyboard) on 1/2 of the felt where there is a gap between the felt and the keysticks. As wood glue hardens, it may cause a clicking noise when the keys fall back to their rest position.

It's not so much the thickness that reduces noise, but the softness of the felt.

[ummagumma]

that is a good tip!! thanks

[goldphinga]

Thick back rail felt is the secret sauce I use. But you have to also mod the entire rest of the action. The results make any Rhodes play better than ever before. But you have to REALLY know your stuff to make it work. Once you crack it, there’s no going back...

[sean]

There are two ways I think that thick backrail felt could be done:

Carve a groove in the case for the felt with a router.  (For the plastic-key Rhodes that don't have a keybed.)

or

Install the thick felt, and sand down the back end of the keysticks to compensate.


I have had the courage to test neither.

Sean

[cinnanon]

Thick back rail felt is the secret sauce I use. But you have to also mod the entire rest of the action. The results make any Rhodes play better than ever before. But you have to REALLY know your stuff to make it work. Once you crack it, there’s no going back...

I did this thinking it was a mistake at first, but I went with it. I had to use the thickest balance rail felts I could find just to get the key height back to normal (I supposed I could have shimmed the balance rail but this is a 77 stage and only has two screws holding the action down). I also had to use thick front rail felts too.

[pianotuner steveo]

Thicker is ok if you know what else needs to be done, but op was asking about 2 layers which I do not recommend.

[bourniplus]

There are two ways I think that thick backrail felt could be done:

Carve a groove in the case for the felt with a router.  (For the plastic-key Rhodes that don't have a keybed.)

or

Install the thick felt, and sand down the back end of the keysticks to compensate.

Yeah, I thought about this while I was in there, but felt like it would have been a crime to carve a Rhodes like that.
All this brings another question to mind: how much should hammer-to-tine distance be? I haven't found anything about this in the forums or in the service manual.  I didn't think of measuring it before installing the bump mod,  but -after shimming the action rail to bring it back close to original- it seems to be around 47mm. (1"13/16) I also measured my MkV, where it's about 50mm (1"15/16).

[cinnanon]

All this brings another question to mind: how much should hammer-to-tine distance be?

I think the more important thing is to get the escapement set/shimmed correctly (when your tonebars are set back to the standard 3/8" height). If that's correct then your hammer-to-tine distance should be fine.

One thing about the bump mod, if you have the era piano with the white felts on the hammer cams (and you remove those and intend on installing the bump mod with felt overtop on the key pedestal) then your escapement / key dip is going to change when the mod is complete (assuming you're using a thinner pedestal felt than the white hammer cam felt). Your escapement should increase slightly, and your key dip should increase slightly as well. So with that said, when you actually do the miracle mod, you're supposed to set the key height first (and key dip). Don't do this without any felt on the key pedestal (remove the hammer cam felt though). Cut a piece of pedestal felt and rest it on top of the key pedestal to simulate what it's going to be like. Do your leveling/key dip, then do the mod.