Ideal leading pattern:

[larudee@pacbell.net]

David,

As a matter of simple physics, it makes no difference whether you put less lead
farther away from the balance rail or closer in, with one stipulation.  The
stipulation is that the key is perfectly rigid and has no flexibility.
Otherwise, both the momentum and inertia will be the same either way.

Of course, we know that the key is not perfectly rigid, so placement of more
lead closer in is probably preferable, all else being equal.  This reduces the
sense of inertia in the key because the part that takes the force of depression
has less mass in it than otherwise, and applies leverage to the part that has
the mass, closer to the balance rail, after some momentum has already been
gained in the key.  Along with the use of cylindrical key bearings, I think this
design is part of what Steinway calls its accelerated action, but I am prepared
to be corrected.

Paul Larudee

David Love wrote:

> I run into this sort of situation frequently and I would like some opinions.
>   Steinway model S ca 1936.  I am replacing hammers and shanks only.  I use
> Steinway hammers full taper, Abel shank 16.5 mm knuckle gives me the best
> combination of regulation/downweight from which to work.  The strike weight
> is medium and consistent throughout.  Key weight ratio is 5.0.  When I
> install the hammers, I will still want to take 2-5 grams off the downweight
> throughout much of the piano (though it is somewhat erratic) to get a 52-48g
> taper.   Doing so does not compromise the upweight.  The present front
> weight of the keys allows me to add lead without exceeding the maximum
> recommended front weight (according to Stanwood charts).  But... the keys
> already have a fair amount of lead grouped mostly toward the balance rail.
> Though the front weight is not excessive, the keys themselves weigh a lot
> because of the amount of lead in them (e.g. C16 = 163g , C40 = 144g, C64 =
> 133g).  I have the option of adding a small lead, or removing two or more
> large leads from near the balance rail and replacing them with one large
> lead out toward the front of the key.  The latter will produce a more
> conventional leading pattern--and involves a lot more work.
>
> My questions are:
>
> 1.  Which one will produce a better feel?
> 2.  Will the difference be significant?
> 3.  Do front weight parameters change with the overall length of the key:
> i.e., is the allowable front weight greater for a model D than for a model
> S, or there other factors.
> 4.  What additional information will be helpful in making a quantifiable
> decision?
>
> David Love
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