Originally Posted by
boomwater
Have had a problem with the derailleur. Intermittent clunk and chain skip when riding. I had a problem with chain suck about four months ago and the rear derailleur jockey cage got bent so had to get a new one...ever since I have a intermittent clunk...The chain skips and gives a almighty clang and then is fine for a bit then does it again.
The symptoms sound somewhat like a tight or damaged chain link, which does not always occur, and when it does occur is less often than every pedal revolution. As the chain has over 100 links it will occur a bit under at most once every 2 rev's of the large chainwheel and once every 3-4 rev's of the small one. Although the chain is new it could be that it was not installed correctly. The biggest difference between skipping from a link problem and one from wear is that a bad link will skip more under low pedal pressure.
The best way to spot it is to shift the chain onto the small chainwheel and one of the smaller cogs (not so small that the chain rubs on a larger chainwheel. Turn the pedals slowly backward and look for the pulley assembly to "jump" as the tight link goes through. You can also push the derailleur body slightly forward to reduce tension on the chain further, which enables you to see more subtle problems.