Wheel Balance Alternative

jim bounds1

New member
May 18, 1998
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Glenn,
Good to hear you got your new rims, I have customers waiting.

The powder you refer to is used by truckers because their tires are usually
so screwed up and are being used so much that the powder helps to keep them
from bumping down the road. It positions itself the same way the
Centramatic rings work. It will probobly help somewhat.

I would prefer to attack the problem in a different way but if you are
happy with the ride, then ride-on!

Let me know how the higher pressure works out, the tire is rated for it and
I have seen conflicting views on this.

Thanks for the input,

Jim Bounds
- -----------------

>
>your shortest trip to a smooth ride.>>
>
>Today, I had my recalled Alcoa wheels (rims?) replaced by the (7) new ones
>that Alcoa had sent to me. As the tires were being demounted from the old
>wheels, the tire man asked me if I had Equal in the tires. Say what? I
>didn't know what he was talking about.
>
>When he got the first tire off, sure enough, there was Equal in it. The
>stuff looked like fine white sand. He explained it self balances the tire
>and does away the need for weights on the wheel. He said many of the
>truckers around here use the stuff and swear by it; not only does it give a
>smooth ride by keeping the tires in constant balance, it also extends tire
>mileage by a very substantail amount.
>
>All my tires had Equal in them. The material had to be vacuumed out since
it
>was contaminated during the demounting/remounting process.
>
>Since they spoke so highly of the product, I had them re-install Equal in
the
>newly remounted tires. It was a Les Schwab Tire store, and I was confident
>they would stand behind the product if, for any reason, it didn't perform up
>to snuff.
>
>It takes a special pressure applicator, and the amount of Equal must be
>measured for the application. In the 225/75 R16 tire, it takes 3 oz. of the
>material, and is installed through the valve stem. Kind of fun to watch.
:-)
>
>Maybe it's all smoke and mirrors, but I'm looking forward to a smooth ride
at
>any speed with Equal, and no shimmys or shakes between 100 and 200 mph... as
>the race drivers claim.
>
>Equal costs a little more than traditional balancing ($10 v.s. $7) but, if
>you can believe the claims, it may do a better job long-term. I'll report
>back in about 30,000 miles. Promise!
>
>One more thing; I had them fill the tires to 80 psi, and was very pleased
>with the ride on the way home. I'm also comforted now, knowing that each
>tire is safely capable of carrying 2,680 lbs. They are Michelins with
>polyester sidewalls; maybe not blowout proof, but I've been told they are a
>lighter tire, more flexibile, and have superior heat dissapation to defend
>against catastrophic failure (as compared to an all steel tire... Goodyear
>G159; Michelin XPS Rib) and cheaper, too. To each his own. :-)
>
>Glenn
>78K OR
>High on Alcoa and Les Schwab Tires (throughout the northwest)
>
>
Jim Bounds/Co-op Motor Works Orlando www.gmccoop.com
 
Jim wrote;

>The powder you refer to is used by truckers because their tires are usually
>so screwed up and are being used so much that the powder helps to keep them
>from bumping down the road. It positions itself the same way the
>Centramatic rings work. It will probobly help somewhat.

I've only just joined the list today, and want to say HI and thanks to the
administrators who got it started. I'm from the Toronado List:-) I have a
tremendous love of the GMC MotorHome, and am looking for a dead original '73
Canyonlands/Painted Desert

I'm a salesman for one of the largest manufacturers of 'active centrifugal
balancers' in my area, and found the thread of special interest.I will try
to keep this from becoming a commercial;-) It is not our biggest selling
product, but its actually a good one and we get excellent feedback about it.

Something to keep in mind with any device or method of tire balancing using
an 'active' device- such as powders, liquids, gels or centrifugal methods
like Centramatic is that it still is a very good idea to dynamically balance
the tires anyways. The real benefits of the 'active' methods is compensation
for wear in tires/rocks in tread/mud in wheels etc. changing balance and the
ability to literally keep a wheel so true to the pavement that it can take a
high spot off the tread eventually. Any active device certainly will find
its task much easier if the wheels are reasonably close to balanced and true
to begin with. Any vehicle that has used an active device for a significant
period has astonishingly true treads. If you mount a tire and wheel off such
a vehicle on a tire balancing machine and spin it, there is essentially zero
'wobble'.

The main selling feature for heavy duty trucks is increased treadwear (by
quite a margin most cases) on a motorhome, this is less an issue as mileages
are usually significantly less and the tires might last many years. Active
devices make a real difference in removing vibrations that are annoying in a
coach however, and sometimes can compensate for a slightly flat spotted
tire. Considering the relative costs, they are not a bad idea and certainly
it is not possible for a wheel to be 'too balanced' or the ride of the coach
to be 'too vibrationless'. Balanced is balanced however, and depending upon
ones sensitivity and tolerance to that, and the quality of the wheels and
tires on a coach quite satisfactory results are possible from a variety of
methods, including devices and powders/liquids et al. Much comes down to
what service life you expect, and how you usually use the vehicle. Certainly
the greater the annual mileages and the higher the average speeds the more
the centrifugal devices make sense. This certainly does not describe
everyone's driving style;-)

So, to sum, don't view the devices as so much a way to cut corners, as much
as another enhancement to an already well set up Coach.

Please feel free to contact me if you like either on or off list on any
topic;-)

Brent Covey

deville
 
>Jim wrote;
>>...from bumping down the road. It positions itself the same way the
>>Centramatic rings work. It will probobly help somewhat.
>
>I'm a salesman for one of the largest manufacturers of 'active centrifugal
>balancers' in my area, and found the thread of special interest. ....

Hi Brent,

Welcome to the list. I am very curious about these products. I am having a
problem that looks a lot like a wheel balance problem. I am very skeptical
that putting powder in a tire or attaching a ring to a wheel could solve
the problem. I am wondering if you could explain how these products work. I
don't understand how the fluid or powder or whatever migrates to the
lighter side of the wheel/tire. It seems to me that exactly the opposite
would happen. It seems that the heavier side would tend to accumulate
whatever material is free to move around, thus causing things to become
less balanced.

Any info or links explaining the physics behind these products would be
very much appreciated.

Dave
73 Sequoia
 
>Hi Brent,
>
>Welcome to the list.

Thanks! I've been enjoying it a great deal, I'm very impressed with the
overall knowledge availible on such a broad range of topics even in this
short period!

>I am very curious about these products. I am having a
>problem that looks a lot like a wheel balance problem.

It may be, or it may be a lot of other things- Many vibrations are more or
less built into radial tires as example, and its not really affected by
balance. Its possible to have an immaculately balanced and true wheel and
tire with a hard spot in it that causes a fairly pronounced vibration.
Before anything else, do check the factory shop manual sections on vibration
diagnosis before getting carried away if you feel the wheels and tires are
essentially fairly close to correct balance at this point. Often
substitution of a known good set of wheels and tires will help in diagnosis.

>I am very skeptical
>that putting powder in a tire or attaching a ring to a wheel could solve
>the problem.

I certainly agree it seems like a very unlikely method of balancing a
wheel/tire/drum assembly. If you ever have had a tire with a half cup of
condensate water in it, it is amazingly rough. All of these methods are
somewhat compromised. All do work at some level however. It is important to
bear in mind that NO methods will 'dynamically' (radially and laterally)
balance a tire short of actually attaching lead weights et al to the tire
rims on both sides. For any hope of success, this should definitely be a
first step.

All the other methods have thier strong points and weak points. The
centrifugal ring type devices are not effective unless the vehicle is moving
at least ~20 mph or so, but after that are capable of bringing balance
within a very tight limit. The good aspect is that the tolerance possible to
balance (level of effectiveness) increases with speed, whereas the imbalance
forces in a conventional hammered on weight increase with the square of the
speed. A 1/4oz imbalance is not too noticeable at a low speed, but builds
force as the wheel turns faster. The centrifugal devices are 'set' by this
imbalance force, rather than the actual imbalance of the wheel. Any force
attempting to move the axis of the wheel from a stable point will force the
active devices to compensate within thier limits. Obviously, if a wheel and
tire is wildly out of balance, or not true, you may exceed a particular
device or system's potential to correct imbalancing forces.

The powders are not uniformly effective as a general rule, and have a few
problems, depending upon the brand- some tend to collect moisture and form
small balls which ruins thier effectiveness. Which method(s) you employ on
your own coach is determined by what kind of trade offs you are willing to
make. In my opinion, dynamic balance of wheels and tires is absolutely
needed, and the Centramatics are worth it to preserve your tire investment,
and maintain comfort for the life of the coach. The downside is they cost
more initially. The good part is they should last forever, and can be
transferred indefinitely as you replace wheels and tires in future at no
additional expense.

> I am wondering if you could explain how these products work. I
>don't understand how the fluid or powder or whatever migrates to the
>lighter side of the wheel/tire.

This is one of the things that is easier to demonstrate than to explain,
sort of like how a differential operates- once you've seen it once, you'll
grasp it completely;-) If I can't make it clear in this explanation, well,
its not your fault!

In short, theres one basic plane the spindles can travel in- vertically- for
the most part. You must keep in mind that the wheels are turning, not unlike
a phonograph turntable. Imagine a special LP record playing on this table.
It looks just like a regular LP, except the lip or rim has been curved up
and over itself to make a banking to keep a marble dropped on the LP from
being able to spiral right off onto the floor.Centrifugal force from the
rotation of the tire/ring whatever will fling any materials within the
circumference as far outwards as possible. Imagine dropping several marbles
on our special LP as it spins, ala roulette wheel-, its somewhat like that.

Now, the tricky part- imagine next knocking the table fairly hard from the
'bottom' (your side) with your elbow while the turntable spins with the
weights caught along the rim of the turntable. All the weights will be
displaced in the direction the disturbing force came from. The ones that are
right at the top at the instant you hit the table will remain more or less
at the relative distance to YOU they were originally, but they will appear
to drop away from the 'top' rim of the turntable towards where the force
came from.

In a nutshell, thats how they work- the weights/powders etc are just
conserving thier own momentum, while the tire attempts to jump up and down
from imbalance or a high spot. Every time the light spot or high spot hits
the pavement the tire will lift a little into the vehicle body, which
unloads a proportionate amount of weight from the top of the ring, or inside
tire at top dependent upon the process used, and this will balance out the
forces to a point that no vibration can occur from STATIC imbalance, and
that the tires will slowly knock off a high spot over time in the tread
area. It does not matter where in the unsprung weight the imbalance
originates, as long as the wheels are turning fast enough to carry the
balancing medium (ball bearings in our device) outwards completely by
centrigal force, the method will be totally effective and automatic. Due to
the inability of these methods to balance side to side imbalances, its still
a very good idea to dynamically balance your wheels.

>It seems to me that exactly the opposite
>would happen. It seems that the heavier side would tend to accumulate
>whatever material is free to move around, thus causing things to become
>less balanced.

Yes, one would think! Its a very hard thing to picture in your mind, I feel
now like I do when I try to explain the oil flow of a torque converter to
someone, hehehe!
>
>Any info or links explaining the physics behind these products would be
>very much appreciated.

The website for my outfit has some information although its a bit heavy on
testimonials and a bit short on diagrams. There is one that illustrates the
basic concept well however.

www.centramatic.com

Dave, I hope this helps!

By the way, is there a picture of your Sequoia on line yet? I always liked
that combo!

Brent
 
Sell them to a die hard 16.5 in E rated steel belted tire user like me.

Bob Morris
Jayhawk
74 Elganza SE
Cortland NY

- ---- Original Message -----
From:
To:
Sent: Thursday, July 22, 1999 3:00 PM
Subject: Re: GMC: Wheel Balance Alternative

> In a message dated 7/7/99 3:38:41 PM Eastern Daylight Time,
deville

>
> and maintain comfort for the life of the coach. The downside is they cost
> more initially. The good part is they should last forever, and can be
> transferred indefinitely as you replace wheels and tires in future at no
> additional expense. >>
>
> What happens if you switch to Alcoa 16" wheels? The rings for the 16-1/2"
> will no longer fit. I have Centramatics but will be going to the Alcoa
> wheels soon.
>
> Emery Stora
> 77 Kingsley
> Santa Fe NM
>
 
I just had equal put in all six wheels this week. It took a while to find a
tire dealer that had it. Unfortunately I didn't watch them as they did the
work. As they where doing the last wheel I walked out to see how it was
going and was appalled to find out that they removed all of my existing
wheel weights and did not use the applicator (as recommended by the makers
of Equal). I guess when I asked if they installed Equal in tires I didn't
think to ask if they did the installation per the manufacturers
instructions. Instead they just broke the bead of the tire and poured the
stuff in!

To my surprise it rides great. I will know for sure this weekend. I am
hitting the road for 10 days. We will see what happens. I will be amazed if
this simple solution turns out to solve my problem. Sure wish I had tried
this first, before having the wheels balanced, installing new shocks and
having the wheels balanced a second time....

Dave
73 Sequoia