Originally Posted by
dsbrantjr
The symptoms you are describing seem to indicate friction somewhere in the system. Did you replace ALL of the shift housing runs, including under the bar tape and the last run going into the derailleur? I would suggest solvent cleaning and relubricating the derailleur. Check the shifting action by pulling on an exposed run of shift wire and see if there is still sluggish response moving to the small cogs; if so there is still excess friction somewhere. A remote possibility is a weak return spring, but unless it is heavily corroded that is unlikely, or the shifter is not paying out cable correctly; the wire pull test should diagnose this.
Also, if the hanger was bent it is possible that the derailleur has gotten damaged as well.
All the cables and housing was replaced from the shifter down to the derailleur. Mechanic confirmed it all looked good. We took the derailleur off the bike to inspect it further, seems to be in tiptop condition from a visual standpoint. I think a thorough cleaning is in order before ordering a new one. I'll take it off the bike and clean it and re-lube it. Will also do the same to the shifter to be thorough.
Mechanic said the return spring looks good and feels plenty strong. Also, said derailleur appears undamaged but admitted that it can be hard to tell just by looking at it.
Can you elaborate on what the wire pull test is?