Yes, tyres are heavily automated, but there will be very sight differences in weight of materials, composition of materials or tooling wear. Its possible you may have a tyre manufactured when the tooling is almost worn out, but still within design tolerance. The tyre is built to be fit for purpose as a cost in a world where nothing is perfect. Your always going to have variance.
I just trying to get across that there are still many variables that can change over time in a fully automated process, and this will make each component unique.
To compare, look at Car manufacturing. They are built on a very precise production lines but there are still people who get a lemon or the friday afternoon car. This can apply to just about most manufactured goods.
Daewar wrote:I think tyres are still hand made and each tyre is slightly different. Look at F1 racing & even with the best tyres money can buy there can be differances
It's fairly well automated these days https://www.youtube.com/watch?v=1o9mVZxoayA
F1 tyres may well be more manually made given the low volume made compared to car tyres