I am trying to make a decision on if my transmission may be worn out or if I am just not adjusting it properly. I have configured a number of bikes in the past but I cant get this one to work with me. I am starting to wonder if I am fighting a loosing battle. The transmission is Ultegra 6600. The shift levers and rear derailleur came to me from a barn. They sat in a box in that barn for an unknown time after the bike was hit by a car. The rear wheel was damaged so it is possible the derailleur suffered damage as well. It has no marks, or blemishes and appears to be in perfect working order. The levers have some rust on the adjustment screw, and some of the pin heads looking at at the bottom of the levers. I cleaned the levers with solvent and liberally applied T9.

The symptoms I am having is with proper fine tuning the shifting for the rear. I can get it to where it will either shift up consistently or shift down consistently. The best adjustment I have been able to get is so that it will up-shift with each click but to down-shift I have to shift and apply just a fraction bit more pressure to the shifter to get the chain to jump to the larger cog. I can adjust the barrel adjuster a tiny bit and remedy this so that I can down-shift smoothly but the up-shift will not release enough cable for the chain to move to a smaller cog.

This is on a steal frame and I have already used a derailleur straightening tool to properly align the mount. I have also played around with wheel placement in the dropouts. I haven't found a solution yet. Could this be a telling symptom of worn out equipment or do I just need to keep messing with it until a solution is found.

The frame is a Puch Force XII the cogs are a ebay purchased Dura-Ace that appear to be lightly used. The chain is new KMC.