Thomas R. Adams and Joe Bender-Zanoni have brought back memories and I'd offer a couple of observations:
1) I never had trouble with the friction adjustment loosening up. 2) I often mixed a Shimano left with a Suntour right BarCon. The Shimano has a noticably larger barrel, so it wraps more cable and shifts a triple front more quickly. On the other hand I liked the precision of the Suntour for the back end.
Your mileage may vary.
harvey sachs
mcLean va