Here's a point about knockoffs I don't think was mentioned. Knockoffs
tighten counter to the direction of rotation (see below). This also means
that if the knockoff strikes something out on the track, the impact will
tighten the knockoff, rather than loosen it. This was REAL important in
the early days when the tires were so skinny that the knockoffs stuck
out past the wheels. The fronts on my F. Jr. are like this. They're
Borrani, but the same principle applies. They tighten back at the top,
or counter the direction of rotation.
Did it ever occur to anyone that the reason the safety wire comes back
loose after a track session is that the wheel is flexing side to side? I
believe you said you were using some modern sticky rubber. Wouldn't this
cause the wheels to flex more? I can think of a real simple way to verify
whether the knockoff is getting tighter, or the wire is getting stretched.
Paint stripe the knockoff, or use a fine tip felt marker. If the knockoff
is getting tighter, the stripe will be broken in the tighter direction.
If the knockoff isn't moving, look for another reason the safety wire is
loose. Is centrifugal force on the wire making it stretch? How about air
resistance? My money's on wheel flex.
I don't think inertia has very much to do with it. Your exercise in physics
did point out that most cars brake better than they accelerate (dragsters
excepted). If the wheel rocks back and forth slightly on the splines, it
will rock harder when braking than accelerating. This would tend to force
the knockoff on harder. I think the paint stripe is the only way to settle
this discussion. Who's game? My next event isn't until mid May.
Carl McLelland wrote:
>
> Thanks to all who responded to my question of why one of my knockoff's
> tightened after racing. Your responses (1) generated some brain functions on
> my part and (2) answered a question of why the knockoff threads are
> directional (clockwise tighten on left side and counterclockwise tighten on
> right side) and why they "unscrew" if mounted on the wrong side.
>
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