Suntour Cyclone RD, can't adjust it from 7 spd to 6 spd?
I have a Suntour Cyclone MKII RD, which supposedly is able to handle up to 32T on my Vitus. It was working well with a no-name 7 speed freewheel with (I think) 28T as the biggest, and a KMC Z-chain, and Campy friction shifter.
As an experiment I tried a 6 speed Shimano "corn-cob", which only goes up to 20T. Strangely, I can't get it to shift onto the 20T, and I'm out of adjustment! This does not make sense to me since I know it can handle the range. What am I missing?
Same wheel, didn't change spacing. The 6 speed is a narrower stack. The Cyclone has only 3 screws, L, H, and the chain wrap, which I dialed all the way in. The chain just doesn't make enough of an angle going in to pick up the sprocket, just chatters.
Sorry but it's not clear that you did try the limit screw? As mentioned, the freewheel body may have a different relative position. If your freewheel is a Suntour Ultra, they have a history of being fussy with some chains.
Kirk Frameworks JKS-C, Serotta Nova, Gazelle AB-Frame, Fuji Team Issue, Schwinn Crosscut, All-City Space Horse
Yeah, that was going to be my next suggestion - taking a link or two out of the chain. if you've got it on a stand, you could manually push back on the derailleur to mimic adding tension / adjusting the B-limit while turning the cranks to see if that solves the problem, or slide the wheel forward in the dropouts to do roughly the same.
Thanks,I'll try the B-limit the other way (vertical drop-out on this bike, no adjustment). I already have the L limit fully out. The purpose of the experiment is to see if I can eliminate auto-shifting I get under certain conditions. The narrower, 6 speed looks like it will have a straighter chain line, which should help. I also have a wider Nashbar 6 speed freewheel to try.