Mark,
You're driving proof that braking can loosen the knock-off, and I've had
many philosophical discussions with mechanical types as to whether the
convention is the best use of "handedness" of the threads! Maybe any vintage
racers in the group can shed further light? Perhaps we can conclude that
effective brakes were less of an issue when this convention was established.
Cheers,
Nigel
> -----Original Message-----
> From: Mark McCombs [SMTP:loadcel4@infinet.com]
> Sent: Monday, September 25, 2000 10:40 AM
> To: Nigel Geach (CRFPULP)
> Subject: Re: Thread Direction
>
> I once had a TR-3 wheel fall right off the front left, by heavy braking
> and
> having the wheel spin over its worn splines, unspinning the spinner, (it
> fell of first) , the wheel immediately thereafter. It was not pleasant. I
> always thought they "sided" the threads for this phenomena.
> Mark
> -----Original Message-----
> From: Nigel Geach (CRFPULP) <Ngeach@fccl.com>
> To: 'lbprince' <lbprince@email.msn.com>; mg-t@autox.team.net
> <mg-t@autox.team.net>
> Date: Monday, September 25, 2000 12:42 PM
> Subject: RE: Thread Direction
>
>
> >Ben,
> >Part of the answer is in your nearest Engineering Dynamics text.
> Visualize
> >yourself in a moving frame of reference, ie travelling with your car at a
> >steady speed down an endless highway, and observing the right front
> wheel.
> >The wheel is turning clockwise, and the knock off is also turning
> clockwise.
> >In order to sustain its angular momentum in a clockwise direction, a
> >continuous (albeit small) force must be exerted on the knock off by the
> hub.
> >If the knock off were a right hand thread, this rotational force relies
> only
> >on the friction of the thread, and if that friction slips, the knock off
> >would spin off. Hence the use of a leftt hand thread on the right side .
> >Repeat the visualization for the left side wheels, and we conclude a
> right
> >hand thread is required. Braking will tend to loosen knockoffs, but
> >subsequent acceleration will tighten them again!
> >However, the TD/TF thread question baffles me completely!
> >Cheers,
> >Nigel
> >46 TC 0710
> >73 Triumph Trident
> >
> >> -----Original Message-----
> >> From: lbprince [SMTP:lbprince@email.msn.com]
> >> Sent: Saturday, September 23, 2000 7:06 AM
> >> To: mg-t@autox.team.net
> >> Subject: Thread Direction
> >>
> >> As we all know, wire wheel knock-offs on the left side are right-hand
> >> thread
> >> and those on the right are left-hand. These orientations supposedly
> keep
> >> the knock-offs from loosening, particularly with heavy braking.
> >>
> >> Per the Workshop Manual, the axle nuts on the TD/TF are a different
> story.
> >> The left-front nut is left-hand thread, and the right-front nut is
> >> right-hand thread (page K.6). Both sides on the rear are right-hand
> >> thread
> >> (page H.5).
> >>
> >> Aside from dismissing it as being "typically British", does anyone know
> >> the
> >> reasoning for all this?
> >>
> >> Ben 54 TF 1500
> >>
> >>
> >
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