Adamas AX was Shimano's upper, entry level Aerodynamic group, below Dura-Ace AX and 600 AX. There was lower, unnamed series of AX parts that included Positron derilleurs. It was produced circa 1981-1983. There was lots of trickle down technologoy from the higher groups. The Direct Cable Mechanism on the rear derailleur eliminated the friction of the cable housing. The brake caliper desgin was called Para-Pull. The inital lever pull brough the pads very close to rim, after which the pad stroke matched the lever stroke. The design also ensured balanced braking between the left and right arms, provided you centered them properly. The hub flange design was called Direction 6 and facilitated wheel building and reportedly resulted in a stronger wheel.

I had a Dura-Ace AX group. While it did not fare well in the marketplace, it was a novel, technologically advanced and excellent performaing group. My favourite feature were the Direct Drive pedals, which provided an extremely stable platform by putting the sole of the shoe on the pedal axis. Unfortunately, this feature did not trickle down to Adamas AX.