In the 130107 MMD Vincent Thébault said: "I find that the touch weight
of my Steinway Duo-Art OR is too heavy.  I wonder if it's a 'common
illness' of such piano or if there is a solution to have one with a
lighter touch."

Vincent, if you feel the touch is too heavy, there are many ways to
change it. The first thing is to find out how much of the touch is used
up lifting the weight of the action, and how much is effort is wasted
by friction.  This is not something you can do in a couple of minutes,
as it takes careful measurements.  It has been my experience that most
technicians do not know about this.

Here is an example of the funny relationship between weight and
friction: I was carefully regulating the new piano mechanism of my AR
Steinway, and one of the measurements I take is how heavy the front of
the key is.  This is usually changed by adding or removing lead.  I
came across one key (#7) that had a larger lead weight than its
neighbors, and this was a Steinway factory original action.  I realized
that, when this action was being made, note 7 had a higher friction
than normal, and so the factory technician did what just about every
other tech would do: increase the lead in the key, so it could overcome
the extra friction.

Once I installed a new action, there was no longer a high friction on
note 7; so the old factory-installed lead weights in the keys were no
longer correct.  I had to remove some of the lead before I could get
note 7 to work like the others.

I am willing to write out the formulas, if anyone is interested.  As
for Robbie's comment about improper key geometry, I interpret this to
mean that, if ANY action is not regulated properly, you are not going
to like the feel of it.  This has nothing to do with key length,
despite the belief of many people, who are just plain wrong.  I am not
aware of a "different geometry" for mechanical playing versus hand
playing, although we know that hand-playing allows the pianist to feel
each note individually, while mechanical playing is granted a larger
tolerance, and if we can get all the notes to play, then the machine is
"good enough."

Randolph Herr