What I know is there was Rival at the bottom end (I had a Gitane Prologue from that era with it) and I believe two levels above it. Supposedly, the higher levels were rebadged Campy although I don't know what models. Sachs offered an 8spd Ergo lever at one point on one or more high end groups. There were at least two groups on the moutain side. The mountain groups offered gripshifts in either shimano-spacing or their own (Campy perhaps?) I had been running a Neos RD on my beater until yesterday, when a pin fell out of the paralellogram. I thought it shifted well and looked a little better than all the Shimano/Suntour offerings of the early nineties.