Kleingeld Conradie takes life seriously. This may be because he is an elder of the Gereformeerde Kerk, or it may be because he’s a banker. Most people think it is because his wife is one of those people who cannot tolerate any of the niceties of being alive, such as having children, enjoying the outdoors, listening to good music, or even something really important like taking the occasional alcoholic beverage. To make matters worse, Kleingeld usually wears a dark suit.
His daily transport, a 2007 Ford Fiesta, is pristine and gets washed every week. It has been very reliable but lately developed a vibration through the steering wheel. It starts at about 90 km/h but settles when he goes faster. He had taken the car to three different tyre dealers to get the wheels balanced but was always disappointed. The last dealer used an on-car balancer, but it made only a slight difference. He eventually brought the car to us so that Syd could take a look at other possible causes.
Syd examined the car for play in the steering box, suspension joints or the wheel bearings, but could not find sufficient variation to set any warning signals ringing.
I was eventually dragged into a discussion on what to do next and decided to ask advice from my friend Ziggie. He runs a tyre shop in the nearest large town and offered to take the car under his wing.
Kleingeld agreed to take his car to Ziggie’s tyre shop and we sat back and waited for the result.
Ziggie phoned me that afternoon with the news that the car was fixed. His balancing machine operator had simply balanced the front wheels correctly to a close tolerance.
When I asked why the other tyre dealers could not do it, he explained that there are a number of possible reasons. The way the vibration appeared and disappeared showed that the wheel was dynamically unbalanced. This needs more precise measurement to cure than static unbalance, which simply gets bigger as the speed increases. Some tyre dealers employ untrained operators who tend to be lax when it comes to feeding important information like the hub-to-machine distance into the machine, or who are careless in placing the balance masses in the correct places. It’s also true that very few machines are regularly calibrated and the rough handling that they usually receive tends to reduce their accuracy.