Are cups for ISIS bottom brackets universal?
 

Since ISIS was and open standard (http://www.isisdrive.com/), does that mean that the corresponding cups can be exchanged (assuming correct thread) from one model to another. For example, if a cup is missing or damaged, can I just get another ISIS Bottom bracket an use its cups?
Is there a source to order ISIS cups?
Thanks

Just about every ISIS Drive BB is a cartridge BB so I'd imagine that you're not actually referring to the cup but the spacer ring. In order the use a different spacer ring both BBs have to have the same cartridge diameter, it doesn't even have to be from an ISIS Drive BB. This dimension is not part of the spec.