Originally Posted by Landgolier

Oh, and for the person who is about to correct me by saying that a JIS crank will just sit 4.5 mm farther in on an ISO spindle

Originally Posted by Sheldon Brown

If you install an ISO crank on a J.I.S. spindle, it will sit about 4.5 mm farther out than it would on an ISO spindle of the same length.

Confersely, if you install a J.I.S. crank on an ISO spindle, it will wind up about 4.5 mm farther in than it would on a J.I.S spindle of the same length.