Touchweight
A piano action that feels just right
You’ve probably noticed that from one piano to another, the touch can vary significantly. Some pianos feel heavy, others much lighter—even between pianos of the same model, brand, and year of manufacture. For a long time, this phenomenon was poorly understood by both piano technicians and pianists, and largely ignored.
Touchweight
OBSERVATIONS
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The traditional method, still widely used today, involves measuring only the downweight and balancing the keyboard accordingly, without taking into account the hammer weight or the action’s geometry.
This method doesn’t consider variations in friction from key to key and, more critically, adds a great deal of inertia when using heavier hammers—something that significantly hinders pianists, especially in fast passages.
Fortunately, solutions exist. Thanks to the remarkable work of American technician David Stanwood, we now know that hammer weight is a crucial factor. Just 1 gram of hammer weight translates into 5 to 6 grams at the front of the key—that’s roughly 10% of the minimum force required to depress a key.
COMMON SCENARIO
Hammers have been replaced and the touchweight feels heavier.
You’ve had your hammers replaced with new ones, and suddenly your action feels unplayable because it’s too heavy. Yet your technician assures you that the keyboard was balanced according to factory specifications—and that may well be true. However, the technician likely did not account for the weight of the new hammers, and instead added excessive lead weights to the keys to compensate.
This situation is easy to understand if you imagine two seesaws of different weights and balance points.​
Let’s imagine that the two children weigh 30 and 31 kg, and that the two elephants each weigh 100 and 101 kg. In both cases, the weight difference is 1 kg, but the seesaw with the two elephants will be much harder to move than the other one. That’s a difference in inertia. The same thing happens inside the piano, where hammers of a certain weight are on one side, and a key with a certain number of lead weights is on the other side of the fulcrum.
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This problem is widespread, and for a simple reason: over the last century, hammer weights have increased significantly. Hammers produced around 1900 were much lighter than those used today. At the time, the geometry of piano actions was designed for those lighter hammers. When we replace old hammers with modern ones while keeping the original action geometry, the leverage no longer corresponds to the new parts' weight, and the resulting touch becomes drastically different.
Precisely adjusting each hammer’s weight and the friction according to the action’s design and the pianist’s preferences is therefore essential.
This kind of precise, time-consuming work often clashes with the needs of mass production, which is why factories usually don’t take it into account—resulting in inconsistency and lack of precision.
Fortunately, as technicians, we can take all of this into account and modify the weight of existing parts, as well as the action’s geometry.
OUR WORKING METHOD
The action tailored to your own taste.
We use a method based on the development of our own proprietary software, created for piano design. This software includes a database of all action parts currently available on the market. The time needed for measurement is drastically reduced because we simply select the new parts we’re using, and the software performs all necessary calculations.
This results in considerable time savings, making the added cost to the customer negligible. Rather than incurring several thousand francs in unnecessary labor costs, we can more easily propose replacing parts with new ones. This is clearly more beneficial for the customer, who ends up paying for new components rather than hours of redundant labor spent measuring original parts.
Our method is protected by copyright, and is already being used by some of our professional clients, including piano manufacturers and technicians. We are currently studying the launch of an application that would make this tool available to all piano technicians.
We are regularly invited to give lectures and training workshops on this subject for piano technicians around the world—in the United States (2024 and 2025), Switzerland (2023 and 2024), Germany (2025), and New Zealand (2019, 2020, and 2021).