Bicycle Mechanics - Chatter, skipping on rear cassette

Hello. I have a problem that just recently started happening - the rear cassette is making a chattering noise and a few other things all started:
1. Noise chatter from rear cassette
2. After shifting in the midline and small cogs, the chain will occasionally move to another cog.
3. Sometimes when I shift it doesn't 'take' but seems like it is stuck in between requiring another shift.
4. When I shift sometimes the chain 'stands' on the teeth of the cog for a few seconds before dropping in
5. Sometimes when I pedal backwards the chains will go up on a certain cog

This all started on the last ride after a trip where the bike was in a van but suffered no known accidents or damage.

Anyways, the wifes bike, new chain and the cassette is newer as well. 9 speed ultegra.

Ideas?

Adam

I'm guessing the RD just needs a bit of fine tuning. Park tools has an EXCELLENT Tutorial on Adjustments (http://www.parktool.com/repair/readhowto.asp?id=64). One piece of advice, if you do it JUST like they say, it's easy. If you decide to do it by random twiddling things, you will end up chasing it all over the place. When you're done, your wife will think you are true 'bike mechanic stud' and will probably ravage you right there on the floor. (Ravaging NOT guaranteed, Your Mileage May Vary, Offer void where prohibited)

Steve W.
Who LOVES the park tools site, thinking about getting "The Big Blue Book"

Could be a bent derailleur hanger as well, if the bike was laid right-side-down in the van...

Is it a Specialized? First, check the derailleur hanger as was suggested above. The specialized derailleur hanger on my wife's Allez Vita is very easily bent for some reason. Second, check the cables. My wife's bike came with a very short rear derailleur housing with plastic ferrules on both the chainstay stop and derailleur ends. The combination of plastic ferrule material and the short housing eventually bent the ferrule feeding into the derailleur, which apparently caused similar problems to what you describe. Replace with longer cable and housing as well as a metal ferrule for the derailleur.

one other thing came to mind, check that all the ferrules are seated in their housings, and the cables are fully seated in the ferrules. I had that happen on my Cdale one time, if they aren't seated all the way, it will throw the tension off just enough to cause problems. That could be caused by something as simple as a cable getting snagged just a bit when you put it in / out of the van.

Yeah, this sounds more like a cable problem like Mentor says. Also looks for any kinks or tight spots along the cable. See if the cable is passing through the quide under the bottom bracket correctly. And it may only need a simple tension adjustment at the rear derailleur. You could try the barrel adjustor a quarter turn at a time.

Al

Ok - turns out it was a cable problem. It was very loose, guessing it got caught on something and stretched during its time in the van? Anyways, after following the Park site (several times) I adjust the limit screw slightly and then many turns on the barrel adjuster and now it is working fine.

As always - thanks for your help.

Adam

Ok - turns out it was a cable problem. It was very loose, guessing it got caught on something and stretched during its time in the van? Adam

Check your cable to derailleur binding bolt. If the cable caught on something it make have slipped where attached to the derailleur. If that is the problem then you should take it loose and go through the complete drill at the Park Tool site. These are good skills to learn anyway. And anytime you attach a shift cable you need to flip the small shift lever several times and pull the free end of the cable to make sure all of the cable is out of the shifter before attaching to the derailleur.

Al

Check your cable to derailleur binding bolt. If the cable caught on something it make have slipped where attached to the derailleur. If that is the problem then you should take it loose and go through the complete drill at the Park Tool site. These are good skills to learn anyway. And anytime you attach a shift cable you need to flip the small shift lever several times and pull the free end of the cable to make sure all of the cable is out of the shifter before attaching to the derailleur.

Al
Or else you will very carefully adjust your 10 speed RD to work fine as a 9 speed. Not that I would do that, but it could happen, yea, it could happen... That's my story, and I'm sticking with it.

Steve W.
Who has had enough "Server Fun" for one day