> Ancient technology was astoundingly precise Highly skilled artisans could make one-off pieces fit together exactly. Doing so at scale was prohibitively expen

> Ancient technology was astoundingly precise Highly skilled artisans could make one-off pieces fit together exactly. Doing so at scale was prohibitively expensive, because machine tools hadn't been invented that let you precisely machine things identically. So, if you had a broken bicycle, you'd need a skilled artisan just to repair it- off-the-shelf parts were impossible. Every single bike would have been a unique object. This is how guns, ships, clocks, and basically everything was made before reliable methods of achieving precision were invented at the dawn of the industrial revolution. The antikythera mechanism had inherent looseness in its hand-wrought gears which greatly limited how accurate it could have been. https://en.wikipedia.org/wiki/Antikythera_mechanism#Accuracy https://en.wikipedia.org/wiki/Antikythera_mechanism#Accuracy (source: this book, which I gather is pretty accurate, if pop-history https://smile.amazon.com/dp/B072BFJB3Z https://smile.amazon.com/dp/B072BFJB3Z )