Only issue I've ever had is some surface rust on the mounting bolts. Never had any issues with the Shimano mechs on my high-mileage bike either.
How often do you clean the bike? I always give mine a good going over after the salt is off the roads.
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C'dale BBU('05 and '09)/Super Six/Hooligan8and 3,Kona Dew Deluxe,Novara Buzz/Safari,Surly Big Dummy,Marin Pt Reyes,Giant Defy 1,Schwinn DBX SuperSport,Brompton S6L/S2E-X/M6L-X/S12 T Line
