"Tyres are black. Period," but did you know that it was not the case in the past century since car tyres were popularly seen to have white sidewall. Back in the day, they were known as whitewall tyres.
It was a trend that existed in the automobile industry for a long time and having a whitewall tyre represented wealth and status. There are also other trends like pop up headlights which have vanished completely in the contemporary times. This shows that the automobile industry is evolving and new innovations are replacing the older technologies.
Lets take a look at what are whitewall tyres and how they evolved eventually.
Tyres are made from rubber and we know that the rubber is black in colour. However, pure natural rubber is not an ideal material for the construction of tyres because it will definitely wear quickly. Such a compound will result in quick wear and will lack in traction which is why tyre manufacturers came up with Zinc Oxide which is harder and easy to mix with rubber compounds.
Zinc oxide is white in colour (if you have not guessed it yet) which is the reason why there existed whitewall tyres and comeplete white tyres. They provided the desired traction and were less prone to wear out quickly.
Also See: Know The Key Milestones In The History Of Tyres
Later, the manufacturers came with a genius plan which involved using carbon black in manufacturing tyres. It enhanced the durability of the tyres significantly. In order to save money, manufacturers began using black rubber only in the threads which resulted in the birth of whitewall tyres.
Interestingly, black tyres started to become more expensive than the whitewall tyres and there was a shift in the status structure. Now black tyres are important than the white tyres. Buying a black tyre was not an an easy task in the past since it was expensive.
An interesting fact about the black tyres is that under the black layer of carbon incorporated rubber, it was still white. The reason behind this is that the manufacturers believed that only the contact patch area or the surface of the tyre required carbon black for more durability and traction and using carbon black on the sidewalls meant nothing since they believed that it was a waste of money and effort. However, black tyres were easy to maintain and people did not have to take much care in keeping it clean unlike the white wall tyres.
The Whitewall tyres were not cool anymore and fell out of fashion in the 1960's because of the new radial tyre design. However, for some period of time, there existed narrow white strip which was incorporated on the sidewalls. The white details on the tyres were for some time considered to be luxurious and hence many automobile manufacturers used this feature on there tyres, like the ones seen on Lincoln Continental, Chevrolet Corvette etc but it too became out of fashion in the late 70s.
Now, in the present time, whitewall tyres are used on the refurbished or restored vehicles from the 70s and much earlier. There are still many manufacturers who offer whitewall tyres. However, they could be either painted or some special element other than Zinc Oxide is used to get the white coloured tyres.
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