I got this bike 2nd hand and it came at a good price, but the front derailleur came rusty as shown in the pics above. One of my LBS said that they were unable to do anything as they could not soak the entire di2 front derailleur into de-rusting chemicals.
I would like to know if anybody has experience dealing with this type of rust on a di2? Besides that, if the rust is unremovable, how can I carry out maintenance such that the rust won’t get worse?
by from_9