Derailleur Hanger - how to replace it?
Derailleur Hanger installation:
• When installing a replacement, be sure to clean and inspect the dropout for damage. Do not install a replacement hanger onto a damaged dropout.
• Clean surfaces and apply a light film of bike grease to the dropout to minimize noise or “creaking.”
• Apply Loctite and tighten the hanger nut/bolt.
• Over-tightening screws may strip hanger threads.
• Check to make sure that the hanger screw ends do not contact or interfere with the rear sprocket or chain. File the protruding screw end if necessary.
• Re-attach the rear derailleur to the derailleur hanger and check the inboard and outboard limit adjustment and the index adjustment(where applicable). Be sure to readjust wheel quick release so it is very tight.
• In many cases, a broken hanger could be a sign of a problem with one of the chain links, so unless you check this, the new hanger could fail again due to over-tension in the chain