Zeus Alfa Amateur (1981? version) derailleur

The Zeus Amateur series were Zeus' economy models in the early 1980s. They used the same geometry as most of Zeus' better models, but combined plastic knuckles with rather nasty pressed steel parallelogram plates.

The very earliest versions (from 1981?) were called Zeus Alfa Amateur and had the word 'Alfa' cast onto the b-knuckle. They also did not have a metal plate between the b-knuckle and the gear hanger.

Later versions (from 1982?) appear to be simply called Zeus Amateur and had no writing on the b-knuckle at all. These models do have a metal plate between the b-knuckle and the gear hanger.

The 1980s were a chaotic time for the design of Zeus’ pulley cages. And nothing captures this better than the history of the Amateur. I am not completely sure what the issue was, but it seems to have something to do with chain-wrap. The story may go something like this:

The initial, 1981?, model had a steel version of Zeus’ longstanding pulley cage design, with Zeus’ traditional, elegantly tapered, rotation stop halting the movement of the cage at about 80 degrees to the axis of the parallelogram.
Possibly for 1982 the rotation stop was changed to be a, rather crass, plain cylindrical item. The lumpiness of this stop meant that the movement of the cage stopped at noticeably less than 80 degrees - perhaps 75 degrees.
Then, perhaps in 1983, the pulley cage plates became aluminium. The outer plate was reshaped so that the rotation stop was mounted on a protruding area that allowed greater chain-wrap. The angle was now around 100 degrees.
Finally, possibly in 1984, the pulley cage plates were completely redesigned with the curvaceous shape and more modern geometry used on the top of the line Supercronoss.

While I am reasonably confident about the order in which these changes were made, I am far less confident about the exact dates on which they occurred. I would also note, with some bafflement, that Galli was also messing with their pulley cage plates in a similar way during the same period.

This is a very decent 1981? version of the Zeus Alfa Amateur. Click on the 'Photos' tab and you can just about see the word 'Alfa' cast onto the b-knuckle.

This version did not have a metal plate between the b-knuckle and the gear hanger. You can see the result on this very example. The plastic b-pivot stop that is part of the b-knuckle has been thoroughly mashed by the metal gear hanger. You can see why Zeus introduced a metal reinforcing plate on later versions.