Originally Posted by
The Golden Boy
What's funny is that the 1984 Suntour AR (towards the bottom of the lineup) was all friction but had a barrel adjuster!
SunTour was odd in putting barrel adjuster on their rear derailleurs long before they became necessary with indexed shifting. Even the old "GT" from the 1970s had a barrel adjuster:
But they didn't appear on all their derailleurs, for reasons that are lost to history.