Originally Posted by
KCT1986
Are you using friction shifting (no clicks)? Is the crankset a double with standard size rings, 52/42 was pretty common in '85? Do you want brand new or used?
Based on the 30T cassette, a mountain bike RD would be good option. If you use friction and buy used, most long cage models should work fine. Many older short cage RD won't comfortably do a 30T cogs or have a the total capacity for a 29T wrap. Older MTB RD can be found at good prices. If you currently use a 9 speed chain or plan to soon, a 9 speed RD has slightly narrower pulleys, but this not too critical.
Friction Shifting. Yes, standard double front crankset, yes. Brand new is better, but lightly used is okay. Yes, I'm using a "narrower" 9 speed chain already because I thought it would be necessary for the 9 speed cassette I bought for the back.
Thanks for the MB suggestion, maybe the best option.
For RB stuff, It seems like the only "long cage" models are the 600EX that I'm replacing and the GS dura ace stuff from the 70's. If I'm missing something super obvious, would be open to suggestions!
Thanks again,