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Discussion Starter · #1 ·
A couple of months ago I posted a new thread on 'Wheel Balance problems'. Having conduced various tests, verified that the original garage wheel balance machine was accurately calibrated and having had 4 alloy wheels (+ tyres) balanced off the car a total of 10 times, by the same garage, I went to another garage, and the annoying vibration dissapeared!

The problem:
The first garage only used weights on the inside of each wheel, so that they are not seen on outside.

The second garage used weights on both sides of wheel, as necessary to correctly balance each wheel.

Recommendation:
If you experience similar problems - get wheels correctly balanced on both sides, and forget the athetics of weights on the outside. Alloy colour matched weights tend to blend OK anyway in my view, and may save you banging your head against a brick wall!
 

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Discussion Starter · #2 ·
Conduced = conducted (typo!) |o|

Off course, as per the earlier thread on this subject, there are lots of different causes of wheel vibrations - so this is just one 'new' posibility which hopefully will be of value to someone else.

Thanks to all for previous contributions on this subject, and increasing ones Saab 'wisdom' somewhat more, as always!
 

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I think you should let everone know who the original tyre (non) balancers are as they quite clearly don't know how to balance large alloy wheels except in a cosmetic sense. If they knew their business they would not have messed you about revisit after revisit, they would have recognised the cause and rectified it. I have done some tyre testing with Avon (years ago on a Peugeot 205 1.9 GTi) and their techs would roll about laughing at anyone attempting to balance a 15" 6.5J on only one side, never mind a larger diametertyre/wheel. The variation in shape of a tyre under stress is significant, especially with something as weighty as a 9000, and the criticality of tyre pressure and balance is the only thing between us and a big "off". Please warn us off cosmetic cowboys. End of rant....sorry if I am being rude ;-)
 

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I'm no expert but recall your older thread and even I knew at the time that either the balancing machine was 'off' or they weren't checking the balance after fitting the weights.

I cant understand how people set up in a safety related business when they dont know what they are doing and then prey on the trusting public taking their money for the privelidge (priviledge?). Oh but of course Im stoopid; they're cowboys and should be avoided.
 

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Discussion Starter · #6 ·
As requested, and incase any viewers live in S-Wales, the garage at fault is 'WATTS TYRES' of Cwmbran. They have a few other outlets in S-Wales, but I guess they are not the only ones who balance alloys 'only' on the inside of the wheel.

Bambo, thanks.
The strange thing is that the wheel balance machine registered 0-0 once the weights were applied on the inside 'only'. I watched the guys do it several times, and even rotate the wheel through 90degrees and recheck the balance which also gacve 0-0.

In line with your and Bills comments, I guess that wheel balancing machine is not sensative enough to detect the slight off-balance created when the weights are 'only' on the inside of the wheel. But running at 80 on a big 9000 is a different matter.

For example, if a wheel was out by 5grms on the inside and 10grms on the outside, the garage would ad one weight of 15grms on the inside. This results in a balance across the diameter of the wheel, but not across the edge of the wheel, causing the vibration at speed.

I have told the garage at fault, and they recon that the wheels should be balanced on the axle, which is a load of coblers cos it was fine before I had their tyres fitted!
 

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Tyre balancers can have programs to balance alloys in different places, my alloys have no rim on the outside to attach weights to, our machine at work has 4 programs to balance alloys with the weights set in different places. A lot of older machines don't though. Another thing to consider is that machines can only balance tyres at a speed of 10mph. Don't take this that I'm sticking up for the garage cos i'm not, I have balanced many alloys on the inside with sticky weights and never had any comeback, because they still have two sets of weights to balance them.

Neil
 

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My boss at Rolls Royce in the early 70's balanced his E-type wheels himself, by using bits of plasticine. Honest. Just took the car out and kept fiddling until he was happy. Pre 70 limit he told me he found some of the bends on the M1 a bit of a handful(!!).
At work he was in charge of the most accurate balancing machine anywhere so I suppose he knew what he was doing.
Certainly if you have a niggling problem you can, by trial and error, improve it without recourse to 'tyre technicians'.
FWIW, wheels can be balanced 'single plane' but that plane has to be chosen correctly. Also this becomes less satisfactory as the wheel width increases.
 

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Discussion Starter · #9 ·
Thanks guys.
From 9000CS23T comments, I conclude the tyre fitters were using a modern technique with an older wheel balance machine not suitable for multi spot balancing on the inside of the wheel. So, no problem with the technique, so long as the balancing machine is capable of the job!

Next time I will get the plasticine out... and start lobbing it at them...!
 
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