Originally Posted by
dddd
Altus seemed to replace the very good Titlist derailers, but were made using more economical stamped/folded link plates instead of forgings.
I also recall "model 60" freehubs and front derailers from this time in the late 70's, just a bit more modest than 600.
I've always consider the Altus derailleurs to be direct descendants of the Shimano 500 and 400 derailleurs.
The model 60 front derailleur is what was paired with their original 600 rear derailleur when released in 1975 and replaced by a proper 600 front derailleur for the 1977 model year.