Fixed: Rattle Sound in Bianchi San Jose Drivetrain
 

For a few weeks I have had an annoying rattling sound in my drive train that sounded like a loose chain (it's a fixed gear). The bike went to 2 different bike shops and had a bunch of mechanics look at it but no one could pin point where the noise came from. (Everyone initially thought it was the chain rubbing up against the bash ring, so that's what the sound must be like). Some possible solutions included that I had some metal inside the frame, my chain was worn, I needed a new chain ring and cog.

I finally managed to find the problem last night. There is a metal ring in front of the lock ring and behind the spacers that had come loose. Tightening it solved the problem.

Though I would post here so people using google could find the answer.

just found this!

i had this probelm on my bianchi san jose too! and almost exactly the same story. thanks for posting.