Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Is 62gr down/40gr up weights too heavy for a grand action?

Dear experts, I have noticed that (the tendons in) my hands are starting to complain when I practice for more than an hour every day, which I have been doing consistently since I received my brand new Kawai GX-2. So I read up a lot about regulating, lubricating and easing the keys, static and dynamic weights, etc, both on this forum as well as the articles, trying to figure out whether it is (only) my bad technique that is causing this, or is the action of the piano also too heavy.

I methodically measured a few specs on the action against Kawai's manual, namely the blow distance, which was spot on at 46mm for every hammer, the let-off and drop, and after touch. It is impressive how price the piano is. However, I noticed that the balance rail holes understandably need some easing. This resulted in a dramatic improvement in touch and feel and my ability to play even more piano than ppp! It also resulted in some objective improvement in form of reducing the static downright by some 2gr on some of the heavier keys across all registers.

However, I still find that my hands are starting to develop some permanent tenderness and pain, so I decided to shoot a short video showing how I measure the keys and seek advice from you all, especially since this is my first proper acoustic piano, therefore I do not have any basis to compare. In short, I press the pedal and tap to overcome the initial friction. Here's the video.

As a final note, I do realize that the static weight is not the full story, but it's the best I can do in terms of measuring things. I actually feel that the dynamic weight is much heavier due to the fact that I especially feel the weight more during fast passages.

TLDR, in the video I measure 3 keys, 2 on the bass (measuring 62 down/40 up), 1 middle (measuring 56 down/38 up). The rest of the keys hover somewhere between these two measurements.

Did you lift the dampers before measuring?
Ian

Pooya said "In short, I press the pedal and tap to overcome the initial friction." so I think he is indeed lifting the dampers. My bet is on tight hammer flange pinning. Had this with a 7' Boston and was able to use decimal/inch sized center pins that were just a hair smaller than the metric ones without having to ream the bushings themselves.

Kawai grand action has always been on the heavy side. That is how they are built.

Coming from a digital piano it will be very hard for you to play on that GX-2.

IMO, you should better trade it up for a lighter action piano. Maybe a Yamaha grand.

You beat me to it.

Another option is to not practice over an hour a day until you build up to it! And even when you do, make sure to take breaks every 20 minutes!

With good action geometry as your measurements suggest it’s reasonable that there is excess friction that can be diagnosed and treated. A down weight of 52 to 55 should be achievable.
A good tech should be able to sort that out for you.
That 40 gram upweight will be a blessing when this all gets solved.

Could be the wrong hammer set for that piano, excessively heavy.

Thanks, UnrightTooner. My first guess was also the excess friction, but that is why I measured the upweight, thinking that the friction shouldn’t be able to push up and do work (in the physics sense). But please correct me if I am wrong folks.


Thanks, Hakki. So this is exactly my question: if this kind of weight is in the normal range, it must be my technique that needs to get better. I am willing to take up the challenge, especially if this action is simulating a concert grand better.

Thanks, Gene. This can explain the high upweight. I believe what I am about to say is a red herring, but in multiple places under the keys and on the action frame it says GX-5, but I believe the actions on GXs should be interchangeable (excluding the concert size GXs). Moreover, why should GX-5 be heavier than GX-2?! So your wrong-part theory makes a lot of sense (compared to entirely wrong action). Should I confirm that with Kawai?

There is likely a factory spec for downweight or upweight that Kawai has for this model. Most likely the downweight no higher than the low 50's. It may be that this heavy touchweight might be addressed by your warranty. Most likely Kawai would want a qualified technician make a visit to check the action generally and take his own down and upweight samples. I don't think the factory tech support people will want to go by your measurements as an amateur.

You should understand that by doing some of the needed action work yourself (such as freeing the balance rail holes), you run the risk of potentially voiding your warranty. (I do not speak for Kawai, just stating that one must be careful about such things).

You would better your position by hiring an experienced tech who does key weighting to come in and assess the action overall, and then take his own touchweight measures. Were I the person you hired, I would volunteer to speak with the Kawai tech support person, as he and I can have the necessary tech to tech conversation about the good, the bad, and the ugly. The person on the Kawai end can quickly assess whether or not I know what I am talking about. If he determines that there is a problem, often they will ask me to address the problem on their behalf, for which they compensate me for. All of this I make clear to the customer who has hired me to look at the piano. Serving 2 masters in this way requires integrity on the part of the tech, and clear and full communication between all parties.

Virtually all piano makers are very interested in honoring their warranties and they follow through. I would expect no different from Kawai (and most of us on this forum hold Don Mannino in very high regard). It is uncommon for piano manufacturers to ask a technician to do something that is morally compromising.

I would contact your retailer and or Kawai before doing anything other than diagnosing any excessive friction there may be.
Thinking more about this your 62g down and 40g up suggests action friction is in a normal range
Down minus up divide 2 = 12g
Nothing wrong with that.
Did you have a look at the lead weights in the keys??
Typical is 3 to 4 in the bass tapering to zero or maybe one on the back side of the key in the treble.
Too few weights could be an issue as well.

Check out this thread on touchweight and things Emery did to his GL-10 to address it. He also recently added a touchrail system to his other piano. Hopefully he'll see this thread and chime in, the GL10 has the same action as your piano so he'll probably have some thoughts for you.

Unless you are in the boonies with no dealer nearby, the proper first course of action should be to contact the dealer who sold you the piano. That is what Kawai and other makers would want you to do. Likely, the dealer will send out their own tech.

Both grand actions I have bought improved with a thorough lubrication using Protec CLP and PTFE. Lubricate the backcheck cushions, key bushings (both front and balance rail), which are often tight on a new piano, whippen cushion and damper rail bushings. It is not difficult but somewhat time consuming and can remove excess friction.

Yes, pressing the keys I can see the leads from the side. Also exactly my thoughts on the friction (that it seems normal).

Oh yes, I have read and re-read all of Emery’s threads and you guys’ discussions. Very informative. I am very leery of making changes to my piano at this stage though.

Sage advice.

Update: Just called the Official Kawai Technical Support. The Acoustic Piano representative I spoke with expressed that the 62gr is within spec. Regarding the upweight they mentioned that the 40gr is a bit high but that it’s to my advantage as a player. They said that things are they way they are and that this does not involve the warranty. They suggested to have the piano customized, but I explained that it is not my intention to lighten the piano that is within spec, only to confirm that it’s me and not the piano touch that is the issue. They recommended that I ask my dealer to remove excess friction, but I am not sure they will be amenable to doing that.

The piano is for you, not the other way around, if you don't like it, change it.

I can't remember, did the sale include the first tuning by the dealer? If so, I'd talk to the tech when they come out and see if they will help. The guy who came from my dealer was willing to address anything I had as a concern.

High friction would likely result in a lower upweight than 40g. Find a tech who is well-versed in touchweight modification to diagnose this for you.

Why should the buyer of a new piano have to engage a specialist tech to diagnose a problem with an (expensive) new piano?