Originally Posted by
Rick Imby
The two main Asian tube manufacturers Duro and Kenda pressure test their tubes before deflating them and folding them up. In 30+ years of selling thousands of tubes per year, we never got a bad batch of tubes.
Here are links to a couple of
Defective Bicycle Tube Articles.
Another
Bicycle Tube Article from Down under.
Nope, I don't buy it. I have had several tubes develop leaks around the valve stem, either directly at the stem (not in many decades), or around the boot. There definitely was not any unusual stress on the stem. If it can't take the usual stresses (like with a dead straight and free to move stem), that is a defect. Recently had a Shwalbe ($$$) tube show a string of bubbles around the stem boot in a dunk test.
I quit using cheap tubes because the valve plungers would snap in two (and purchased a mini pump with a hose). A problem I never had in 150k miles, but then had 4 times in one month, while using pumps I had used for years. Probably a bad batch, but still.
Frankly, I would not take the word of a bike shop that tubes are NEVER defective. It is called denial. Sh.. happens, test your spare, and toss the bad ones.
BTW. Why would tube prices be going up significantly?