Have you ever noticed red or yellow dots on the sidewall of a new tyre?
It seems that, although some people work within the industry, not many are aware of the function of these dots. By understanding what they’re for and how to use them properly, your garage can save money and do a more professional job for your customer.
On the sidewall of most new tyres are red and yellow painted dots. If these marks are aligned with particular points on the wheel, you will reduce the amount of weight required for balancing. The less lead weight used, the lower the cost of wheel balancing and the higher the profit on the job.
The Yellow Dot
When tyres are made, they are almost never perfectly balanced, and most manufacturers will place a yellow dot on the section of the tyre where there is least weight. When fitting a tyre, you should line up this yellow dot with the valve stem as this is the heaviest point of the wheel. By aligning the lightest spot on the tyre with the heaviest point on the wheel, the tyre/wheel balance is as close to optimal as can be. So, you won’t use as many weights around the wheel to balance out the tyre and wheel. Fewer weights make for a more balanced wheel, which then means a quieter, more comfortable ride, and a longer-lasting tyre.
The Red Dot
In the same way that tyres are never perfectly balanced from the manufacturer, tyres are never perfectly round either, even when new. They have high and low points which occur where the belts are joined, and these points can cause vibrations when a tyre is rolling. The red dot indicates the tyre’s high point. Most of the time a wheel will also have a dot—either a drilled dot or a sticker to indicate its low point; if you have these marks, you should align the red dot with the mark on the wheel and ignore the yellow dot. By doing this you minimise the vibration caused by the high point of the tyre
Red over Yellow
If both red and yellow dots are visible on your tyre and you don’t have any dots or marks on your wheel, red takes precedence over yellow and you should align the red dot with the valve stem. Cancelling out the high point takes precedence over the lightest point of the tyre, which can be addressed with wheel weights.