[Shotimes] (2) Detailed On -The- Car Spin Balancing (Extremely Long)

[George Fourchy]

Beginning of Part 2....

How do we do it....?

After you have determined the approximate amount of weight to start with, start at
the valve stem, to give you a point of reference easy to find, and apply the weight
to the rim.  I need (and prefer) to use stick on or tape weights, as the Lowrider's
wheels are chrome, and do not have a lip designed for clip on weights.  Your baskets
and slicers have clearcoating, which will be damaged by clip ons, so I'd use
stickons for them, too.  You can put a stickon exactly where you want it, in
addition....clip ons sometimes need to be stacked or jammed together, which is
impossible without creating dynamic imbalance.  Also, stick ons don't show.  There
are good stick ons and bad stick ons, so make sure yours, if you use them, have the
proper durable adhesive backing, and also make sure the rim is clean....REALLY
clean, where you want to put it.  A tapeweight with a bad backing will allow the
backing to peel off the weight really easily.  If it comes off there, it will come
off the car.  Use brake cleaner or carb cleaner on a rag to clean the dirt and brake
dust off the spot prior to sticking the weight in place.  Make sure the spot is
clean and dry.  Now....you have determined, for example, that you need 1/2 ounce to
try to remove the imbalance.  Stickon weights come in strips of 2.5 to 4 ounces,
marked in 1/4 or 1/2 ounce graduations.  Break off the proper amount by bending it
back and forth, or use diagonal pliers, then remove 1/3 to 1/2 of the paper that
protects the adhesive backing.  This piece of weight will be the sacrificial
weight...used only to find the heavy spot, then thrown away when you apply a fresh
section from the weight strip.  If you only take a portion of the paper off the
back, you can use it several times before it won't stick to the rim.  Touch the
sticky part of the backing once with a clean finger.  You want to decrease the
strength of the adhesive, because you are not placing this piece of weight
permanently, and you want to be able to remove it from the rim without leaving
adhesive behind, which is a pain to clean up, and you want to use the weight 3 or 4
times before you need to remove more paper and do the whole thing again.  Place the
weight on the rim in the vicinity of the valve stem, as close to its azimuth from
the center as possible....azimuth is a geometrical dimension, and is a straight line
from the center of the wheel to the edge...theoretically there are 360 of them, like
in degrees in a circle.  Try to locate the weight in a horizontal part of the wheel,
so that centrifugal force will help hold it in place. (Not down by the bead) 
Someplace on the horizontal part of the rim between the spokes or wires would be
good.  What you are doing now is locating the lightest part of the wheel.  After
placing the weight on the rim and making sure it is secure, spin up the wheel with
the engine.  If the weight is in the proper place, balancing out the heavy spot that
is opposite the valve stem, the shaking should decrease in intensity from what it
was before, at the same speed.  (About 1 out of 10 times, I don't need to move the
weight from the first place I apply it....just luck!)  If it is not in the proper
place, the shaking will be more intense, and you know you need to move the weight. 
Take note of the amount of shaking, as changes will indicate how close you are to
the proper spot.  If you need to move the weight, move it 1/4 of the way around the
wheel, either direction.  We'll call this spot 2.  Keep track of where you move
it...use the crayon and mark numbers of locations, so you won't repeat yourself if
you forget where it was two tries ago.  If it gets worse at spot 2, move it to spot
3, which is 1/4 of the way the OTHER way, or HALF way around from spot 2.  If the
shaking is the same as spot 2, then move it to spot 4, which is half way around from
the valve stem.  In one of these locations, the shaking should have improved. 
Remove all your spot marks from the tire using brake or tire cleaner, and start
over, from the spot where the shaking was least. Mark it as spot 1.  (You are
narrowing down the area of your search for the sweet spot.)  Go 3 or 4 inches in
either direction and try it again, marking this as spot 2.  Using this technique,
you can narrow down the location of the heavy (actually the light spot, which is
what you are correcting with the weight) spot, and when it doesn't get any better
moving the weight an inch or so either direction, prepare a new section of stickon
by removing all the backing paper, cleaning the wheel, and permanently mount the
weight.  A weight as small as this one does not need to be split front and rear, but
to decrease any further dynamic imbalance, it should be mounted in the center of the
rim, behind the spokes or wires.  Make sure you clean the spot for it with cleaner. 
When you are finding the light spot, it will be temporarily mounted towards the
front of the wheel, but at weights this small, dynamic errors introduced will be
slight, and eliminated when you mount the weight in the center.  If there is a LARGE
static error to be found, you cannot spin the tire fast enough to start the dynamic
shaking before the static error is corrected or it will shake off the car.  It is
not impossible for a tire to be grossly dynamically out of balance....if it is more
than 2 ounces or so, it should be returned as defective and replaced.  After you
have mounted the permanent weight, spin the tire up to 40 mph indicated, and see how
it feels.  If it still slightly shakes, do the same thing over again, except you do
not need to find the heavy/light spot, you just need to adjust the amount you
applied to that
spot.  Use another 1/4 ounce stickon, (depending on the amount of shaking/vibrating)
temporarily applied to the rim next to the permanent stickon....
the temp one can be outside, where you can reach it, but it needs to be in line with

the permanent one.  Spin the tire again, and check the difference.  If if goes down 
half as much, use a 1/2 ounce piece of temporary stick on, remove the 1/4 ounce
piece, and try again.  If with the 1/4 ounce piece it got worse, try that same 1/4 
ounce piece opposite the valve stem, to easily remove half the weight you applied
permanently.  Whichever of these procedures decreases the shake, you are getting
closer and closer to a perfect balance.  After each successful application of a
permanent weight, spin the tire up 10 or 15 more actual mph, to see how good it
really is.  After you get the hang of this, you can balance your wheels up to 140
mph, 70 on the speedo, with no shimmy at all in the fronts....depending, of course,
on the quality of your tires and wheels. 



And, this won't hurt your differential, as long as there is oil in the tranny, and
you are gentle with the speed changes....go up slowly and smoothly, and come down
the same way.....just let it spin down by itself....don't downshift it or use the
brake until you're down below 20 mph or so on the speedo.


End of Part 2