Derailleur Hanger moves a little - hanger bolt is tight but rotates in dropout
2008 Specialized Roubaix Elite (Triple) with about 2500 - 3000 miles on it. Never dropped or crashed. Hanger is straight and rear derailleur shifts easily and smoothly.
BUT - the hanger can move forward/backward (pivots about the hanger bolt) about 0.5mm
This problem started about 200 miles ago. The symptom was a creaking sound when I put a lot of torque into the crank. I thought it was the handlebars/headset because I had been working on those. It is not getting worse.
Today I finally isolated the noise to the rear hangar. I can make it creak by holding the front wheel against the wall and torquing on a pedal. I put my ear next to the hanger and I can hear it creak. It does take a fair amount of torque - I'm 6' & 210 pounds and have pretty strong legs. It takes about 1/2 my max effort to make it creak.
I've checked the hanger bolt and it is tight - by that I mean that I can't turn the 5mm bolt head while holding the back of the bolt (on the inside of the dropout).
BUT - the entire hangar bolt rotates easily within the dropout if I don't secure both ends of the bolt.
1) Is a little creaking and 0.5mm forward/backward movement a problem?
2) How do I break the hangar bolt loose? Using my 5mm L-shaped allen wrench - I can not turn the bolt head loose from the backing when I prevent the backing from turning. The bolt head (5mm) is clean and the slots in the backing are clean and straight. Do I just use more torque - I've read else where the bolt should be 4 - 5 Nm but this way is way tighter than that.
3) What would cause the hangar bolt to become loose in the dropout? I hope the answer is not an ovalized or enlarged hole in the dropout?
4) Can I keep riding the bike until I can fix the problem (if it is a problem)?
depending on the hanger design you may need to file it a bit because the threaded boss protrudes too far. hangers are held on with a chainring style bolt too. for the creaks. remove the hanger and grease all surfaces and reinstall. clamp wheel firmly. can also grease drop outs.