Message-ID: <001501bec2a3$c81db340$292f1e26@t3g3m5>
From: "Jeremy F Fisher" <exhibs@mindspring.com>
To: <Lancair.list@olsusa.com>
Subject: Nose Wheel Shimmy
Date: Tue, 29 Jun 1999 22:53:48 -0400
Mime-Version: 1.0

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If you look at just about any fighter, they have twin nose wheels.  It has
always been my understanding that this is because it is the most effective
way to prevent nose wheel shimmy.  When I was learning to fly a long time
ago on the Jet Provost, it had a single nosewheel.  However the nosewheel
tire was molded so that it was "U"shaped in section, with the center section
of the tread recessed, and a ridge about 1 inch wide on either side of the
tire.  This effectively simulated a twin nose wheel assembly, and prevented
shimmy.  If the outer portions of the tread were worn down to the center
portion, that was a "no go", as you could then encounter shimmy.

Better men than me can work out why this works.  It does however bring up
two points.  If your tire pressure is decreased, the cross section will be
flatter, getting closer to the ideal twin tire situation, which confirms
what has been said previously in this forum.  Secondly I do not know if
anyone makes our size of nose wheel tire with the "U" shaped section, but if
such a tire were available, it would probably provide a more effective
solution than any change to the nose gear strut.  After all, even the
factory has suffered from severe shimmy.

All this is theory at present, as my part built airplane is sitting in a
storage unit while my house is being built; very frustrating, leaving me
with time to write!  If anyone in Northern Virginia has a 360, part built or
finished, that I could see and learn from, please email me directly.
Thanks.

Jerry Fisher

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