alathIN

I picked up a Cannondale Slice 5 105 off of ebay. Based on appearances, it looks like someone got this bike, tried a number of very strange things to make it fit, never did ride it much, and then sold it on ebay.

I undid all the strange fit things, put it on my trainer, and rode it fairly regularly through the Winter. Come Spring, I picked up a set of race wheels, put the exact same cassette (but new) on the race wheels, and a new chain. When I replaced the chain, the chain gauge said it was lightly worn but not in the "replace me now!" range.

For a while I was able to switch back and forth from the trainer wheel to the race wheel without much problem - perhaps a barrel adjustment smidge.

More recently, I am finding some irregular shifting that happens with either/both wheels/cassettes.

What happens is that shifting up to a harder/smaller gear on the rear, it will sometimes fail to shift or get stuck in no-man's land. If I shift up to the next higher gear, it jumps straight to that one, fairly smoothly.

Shifting down is problem-free, smooth and buttery.

If I want to shift up one gear, I can click the shifter up two clicks and back down one, and it lands neatly in the one higher gear I originally wanted.

What is going on here? How do I fix it?

corrado33

Um... turn the barrel adjuster a bit clockwise? I mean that's the obvious answer.

If that doesn't work then replace your cable and housings.

My guess is that in replacing the wheel you bumped the derailleur and slightly bent the hanger.

Slash5

Inconsistent shifting to the smaller cogs usually is a cable/housing problem. That shift works by the derailleur spring and any friction will make it slow or hang up.

alathIN

New cables, and there isnt much housing on this bike. Just the little plastic fittings where the cables go in and out of the frame, and the little bit of cable housing from the frame to the rear derailleur. Is there a need to lubricate those fittings where the cables pass through?