urbanescapee

Hi All,

My wife and I recently moved back to LA from Nashville area and during our drive across the country we passed through a few snowy areas (Flagstaff). Our bikes were on a hitch rack during the drive. Those with experience may already see where this is going... Anyway, my bike is maintained more frequently because it gets ridden almost daily, thus my chain was well lubricated. That is not the case for my wife's bike which rarely gets ridden and really only gets checked out before a ride. Her chain was surely dry after sitting in storage for over a year before our cross country move. I had forgotten that the snowy, salt-treated road spray would be a problem. After the drive and sitting in our new apt for a few weeks, my bike was fine as usual, but her chain was nearly rusted solid. Being a bit cheap I was hoping, naively, that I could revive her chain with some liberal lubrication and not have to go buy a new 105 chain. After placing about a drop and a half of tri-flow on each pivot and waiting about an hour, I tried to give the chain a run through on the bike to see if it had freed up...it didn't and now I have found that the excessive force on the rear derailleur has caused it to do something that I've not seen before. Instead of the spring tension pushing the rear derailleur cage towards the rear of the bike to create the necessary chain tension, it now is sprung forwards so as to no create any chain tension at all. At first glance I do not believe that the torsion spring responsible for this action can be reset because it looks as if the pivot holding the cage onto the rest of the derailleur body is some sort of press-fit or riveted fixture; not designed to be undone. But, if anyone has any tips for possibly salvaging this rear derailleur I'd really appreciate it. It's a 105 10-sp and the bike was purchased new a few years ago.

Thanks in advance for any help,
I'll go kick myself now...

Andrew R Stewart 

The first step is to get that chain off the bike and be able to look at the der's condition without the chain getting in the way. Once this is done then you can rotate the two spring loaded pivots that control chain tension. one is the obvious cage pivot. the other is the upper pivot, through which the frame mounting bolt goes through. It is very possible that this upper pivot has gotten crummy and is now frozen in whatever rotational arrangement the rusty and frozen linked chain had forced it into. this upper pivot is able to be taken apart and cleaned and relubed. Not what I would say is a home mechanic able job if that mechanic has asked the questions that you have. But... Andy.

urbanescapee

Yes, I have already pulled the chain. I have also removed the derailleur from the frame, and removed the cage back-plate and jockey wheels that are mounted within the cage. I have isolated the "cage pivot" as mentioned above as being the problem area. I have found that there is a set screw on the derailleur body which is sort-of near the axis of the cage pivot, as of right now, fiddling with that set screw seems the next step in trying to solve this problem via process of elimination. I was just consulting here if anyone else had experienced this problem to prevent me from making further mistakes in trying to disassemble/repair this derailleur.

Andrew R Stewart 

It sounds like you have identified the problem and know the next step, trying to remove the cage pivot. I have found others who confused the two pivots and their effects when frozen tight. Good luck. Andy.