>>1579953>Why would a sticky shifter cable cause chain skippingBecause if the friction within the housing exceeds the strength of the spring the derailleur would be part-way between gears causing the chain to hop between them.
I guess it could happen shifting in both directions if the shifter allows the derailleur to go slightly past the target gear then fall back a bit when going up the cassette.
I had the problem on 2 bikes with derailleurs where there is a loop of housing going into the RD. Water gets kicked up onto the cable and capillary action lets it work its way into the housing where it gets trapped. It doesn't happen on my touring bike with Shimano's direct cable routing that I think got introduced on their shadow derailleurs.
Removing the cable loop, cleaning it and completely drying usually fixed it. BUT when removing a trimmed RD cable with frayed ends it can be difficult bordering on impossible to get the cable back in.
I found if the housing was contaminated it usually affected many gears. If its only the smallest sprocket, it could be the high limit screw.
