Hi Steve ,
Based on all of this information ...are tapered roller bearings the way to
go , or should I stay with the stock ball bearings and spacer ? What I've
got now is worn out .
Thank You Steve ...and others on the list .
Mark Hanna
AN5L/13731
> -----Original Message-----
> From: Steve Byers [SMTP:byers@cconnect.net]
> Sent: Monday, May 10, 1999 9:06 PM
> To: spridgets
> Subject: Re: Front Wheel Bearings... Explanation.
>
> The discussion below is about 85% correct, but has a major flaw.
>
> If you look only at the section of axle covered by the bearings and
> spacer,
> yes, that portion would be more resistant to bending loads than the axle
> alone because of the increase in bending stiffness (moment of inertia) of
> that cross section. A thicker beam is generally stiffer than a thinner
> one. HOWEVER, the bending loads don't end here. They have to be
> transmitted to the base of the axle, where it joins the spindle. This is
> the critical area, where the maximum bending stresses are (that's why the
> axle cracks here and not out at the tip). The bearings/spacer has no
> effect on reducing the bending stresses here. Why? Because the inner
> bearing is not physically, rigidly, integrally attached to the spindle
> here. It just sits on it (ignoring the oil seal) , no matter how much
> compression it is under. At the base of the axle, the bearing/spacer
> combination has NO effect on the moment of inertia or stiffness of the
> axle, or any capability to transmit or reduce the bending stresses here.
>
>
> Steve Byers
> Havelock, NC USA
> '73 Midget GAN5UD126009G "OO NINE"
> "It is better to remain silent, and be thought a fool
> than to speak, and remove all doubt" -- Mark Twain
>
>
> ----------
> > From: Mike Gigante <mikeg@vicnet.net.au>
> > To: Lancer7676@aol.com; toobmany@bigpond.com
> > Cc: spridgets@autox.team.net
> > Subject: Re: Front Wheel Bearings... Explanation.
> > Date: Monday, May 10, 1999 10:09 PM
> >
> > David,
> >
> > You can buy a crack testing kit from many rural supply places or
> > from pegasus racing supplies.
> >
> > Back to the original question. It is simply a question of engineering
> > mechanics. The spindle is a simple tapered solid beam. When the spacer
> > is in there and correctly pre-loaded you have a composite beam with a
> > much higher "Moment of Inertia". This simply means that for a given
> > bending load there will be less deflection.
> >
> > The composite beam will also ensure that the local stresses on the
> > surface of the spindle are much much lower than without the spacer.
> > Why? Because the spacer is further out from the centreline axis of
> > the assembly it contributes much more to the stiffness and takes the
> > greater majority of the bending load (as tension/compression on
> > the top/bottom half and vica versa) and thus reducing the maximum
> > tension/compression stresses seen by the surface of the spindle.
> >
> > By reducing the maximum cyclic tensile/compression stresses on the
> > spindle, the fatigue life is greatly increased.
> >
> > Note that it is the delta (max tension - max compression) that is
> related
> > to the fatigue life. The fact that the spindle is pre-stressed in
> tension
> is
> > a very minor consideration as far as fatigue life is concerned.
> >
> > Mike
> >
> >
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