Originally Posted by
cyccommute
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In addition, no one tests each tube coming off a production line. That would take hours per batch and be cost prohibitive. Any quality assurance is done by random sample testing…even from your supposed higher quality tubes. .
Sure they do. From Schwalbe's web site
https://www.schwalbetires.com/bike_tires/tubes/all
"All tubes are inflated and stored for 24 hours in order to test for air pressure retention. Afterwards each, individual tube undergoes a careful visual inspection."
Continental also tests each tube. That's why they're more reliable, and also more expensive. You get what you pay for, especially with tubes and tires.