Originally Posted by
sageo3000
I currently have a 68mm traditional 3 piece cup and cone bottom bracket.
if the cups tighten like british/iso (left side tightens right, right side tightens left) style bottom brackets, does it necessarily mean that the thread sizing is that of a british/iso style bottom bracket (1.370" X 24 tpi)?
Not necessarily. For example, Swiss-threaded bikes also have left-hand threading on the fixed cup, but the diameter and pitch are the same as French. A bike shop once almost destroyed the frame of our tandem by making the wrong guess about French vs. Swiss threading.
What make is the bike?