The tiny pieces of rubber sticking out of the tires are called ‘nubbins’, and they serve no purpose at all!
The tires for the vehicles are made in solid moulds. The mould is provided with vents to let out the air or for pumping the rubber into the moulds. The ‘flash’ is the rubber that solidifies in these holes.
These tiny nubbins are pulled out with the tire as it is removed from the mould thus, clearing the holes for the next wheel to be moulded.
You might notice that these bits of rubber are absent from the expensive tires. The manufacturers can use some techniques to ensure the production system catches the nubbins. However, this requires the use of expensive equipment and many companies choose to forgo the additional processing to increase cost-efficiency of their manufacturing process.
Watch the full process here: