That has been my experience as well.  I replaced a main disc rotor and the
Lancair shudder between 20 to 40 knots went away.  Until of course I made a
hot heavy stop with maximal braking efforts and now it is back, subdued and
tolerated for now.


Michael D Smith


In my many years of experience working on airplanes, I have found that
the shimmy problem is not always the nose wheel in and of itself.  An
out of round tire, flat spots, loose bearings, etc. on a main tire will
excite the nose gear and start the shimmy.  Fix the main gear problem
and the nose wheel problem disappears.

duane


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