Re: Re: Taking off knock-offs
Jim Cantrell (jimc(at)sysdiv.sdl.USU.edu)
Mon, 24 Jun 1996 15:00:34 MDT
> will be spinning clockwise, and the knockoff will be trying
> to stay at rest, which will cause it to effectively twist
> or spin counter-clockwise. Now, if counter-clockwise
> was the direction for loosening the knock-off, as it normally
> would be, forward acceleration would cause the knock-off
> to loosen. So, they had to switch the direction of the
> threads on the right side of the car to prevent the knock-off
> from coming loose from driving forward. Therefore, to take
> a knock-off off, you need to hit or spin it the same direction
> as the wheel would go forward.
Actually, the situation is much simpler than all of this. You guys
are pointing in the right direction but not quite there. The knock
off ears have a mass eccentricity relative to the rotation center of
the wheel. The result is that when the wheel spins, the centrifigal
force, which acts radially on the ear mass, serves to tighten the
knock off. This is true regardless of the direction travelled. But
mix up left and right knock offs and/or hubs, then the eccentricity
of the ear will cause the knock off to loosen.
Kind regards,
Jim Cantrell
66 Alpine 2.8L
76 XJ12C
76 XJ6C