Originally Posted by
cyclinfool
On a Italian BB the non-drive side may tend to work the BB cup out as it is normal thread (lefty loosey).
You have it backwards.
Italian bottom brackets have right hand threads on both sides. Since there is a bearing between the BB spindle and the BB shell, the direction of the force is reversed. That makes the drive side want to unscrew itself.
English threaded bottom brackets solve the problem by using a left hand thread on the drive side.