Mirage Drive Chain Assemblies Compared
The V2 style (left), 81202001, has been flattened on each side of the shaft. This rectangular shape holds the threaded stud from turning in the drum when installing or adjusting the tension nut.
Original Style, 81201001, on the right has full threads around the shaft. You must hold the stud with pliers when adjusting this style chain.
The V2, on the top in the following photo, is over three inches longer than the original style assembly. This extra length is so that the cable section can wrap farther around the drum before anchoring. This reduced stress on the cable to stud connection point.