Originally Posted by
cny-bikeman
It means you did not find the leak and need to check it under water, as there is less pressure in the tube when off the tire.. You used the same tube so it is not logical to assume something wrong with the valve. Part of checking the tube for leaks is checking the valve stem.
Yep, you're right! There's a super tiny hole leaking a tiny amount of air. I've never seen something like that before! Thanks for the advice - to check it under water. I did think about doing that, but assumed no way, it couldn't be the tube since it held air. But, makes sense though that there is less pressure when the tube is off the tire.
Thanks for the help!