Originally Posted by sjanzeir

Yup. This is just about as weird as I've seen so far: several tubes, of different brands, material, and levels of usage - all can hold air for days on end, but leak out all their air in a matter of hours when they're inside a wheel. Thick- or thin-skinned, patched up or patchless, brandname or off-brand - doesn't seem to matter. The bubble test reveals no flaws whatsoever.

Could anybody offer an explanation to this?