Well, in the 70's electronics were very expensive gimmicks. Remember the
prices for the first desk top electronic calculators? Nowadays
electronics are not only cheap, they give far more possibilities which
is demonstrated by the latest balancing machines. Also the aligning
machines (or what their name in the US may be) of the old days cannot be
compared with the present ones. The 'tendency for a wheel to turn in or
out' is now measured by one revolution of a wheel and is automatically
compensated for in the measuring sequence that follows. And putting two
weights on a wheel, opposite each other, to compensate is a method of
the past as well.
I would like to add, however, that 'shaving' a tire, like mentioned by
one of the listers, is another possibility to do away with vibrations.
It is sometimes surprising to see that brand new, modern tires slip
through the factory inspection and are put on the market with over 100
thou throw - I had it with a Michelin tire. And as you don't expect such
a manufacturing error it takes a hell of a time before you find out!
Jack Aeckerlin, The Netherlands
1964 BJ8 29432
R. Cobb wrote:
> Jack,
>
> As to dynamic balancing on the car, I found this reference:
> "Automotive Suspension, Steering and Brakes", by Ellinger and
> Hathaway, printed sometime in the 70's or so.
> According to them (after static balance is completed, using the same
> instrument), "Dynamic balance may be checked and corrected on the
> vehicle. The strobe type balance...is used. For dynamic balance the
> vibration sensor is positioned against the steering arm or brake
> splash shield... In this position it will detect any tendency for the
> wheel to turn in or out. The reference mark is again used as it ws
> for the static balance. For dynamic balance, one weight is added
> inside the front of the wheel at the sensor height and one weight is
> added 180 degrees from the sensor at the rear of the wheel on the
> outside. In dynamic balance, equal-sized weights are always used to
> maintain static balance."
>
> I have an old Alemite wheel balancer that can be used as described
> above, but the main problem I have had is with the sensitivity of the
> sensor which controls the strobe. It has proven too sensitive and is
> non-adjustable. Consequently, though I have been able to improve the
> static and dynamic balance of the tire/wheel/brake assembly the result
> is not as good as I would like. I would think that with an improved
> sensing device, and a bit of practice, good results might be achieved.
>
> This type of wheel balancer has all but disappeared in the U.S., with
> the introduction of computerized, off-the vehicle, balancers, but I
> know that it used to be used extensively in the 40's through 60's.
>
> R. Cobb
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