CF carbon fiber lever

[John Formsma]

On Thu, Feb 21, 2008 at 7:25 AM, Mike Spalding <mike.spalding1 at verizon.net>
wrote:

> John,
> Don't you also need to know something about the fiber orientation in the
> CF layup?  Been a while since I played with any of this, but I recall
> being told by a CF supplier that they can vary the modulus by a factor
> of 2 or 3 by adjusting the fiber orientation.  Of course, that was in
> rectangular sections, and maybe the options are more limited in tubular
> CF?
> Mike



Yes, you would need to know the modulus of elasticity.  And from the little
bit I've read, MOE will vary with CF material.  It depends on how it's
manufactured.  I think the tubes are merely rectangular sections joined
together, but I might be wrong about that.  For the CF tubes I've looked at,
MOE varies from 18 to 20.3.  Steel is around 28 to 30 depending on the
alloy.
A wise man once told me you can measure the actual deflection of the lever
by using weights attached to a rope, and noting how much it flexes.  Numbers
on paper don't always exactly correspond to real life.  Actual deflection
would be nice to know.

As I said before, deflection does play a part in how we feel the pin moving,
but it's probably less important than we would first think.  (Assuming a
good lever -- not el cheapo.)

In my own anecdotal experience with different levers, added mass is
sometimes helpful.  It is more tiring after a long day of tuning, however.

-- 
JF
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