I'm riding a 79 Nishiki outfitted with Suntour Cyclone. It's all in good shape, but I feel like I'm fishing for the sweet spots on the RD and there's a been a few starts at traffic lights or pedaling through turns where I unexpectedly drop a gear in the back. I checked the chain tension and it seems a-ok. Haven't checked the cable tension yet though. The Cyclone stuff is good, so it's probably an issue with tuning?
How do you decide: I'm going to see what x or y derailleur performs like now?