Bicycle Mechanics - Chain seems to be slipping/jumping

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|3iker
08-13-10, 12:01 PM
This started to happen this morning on my ride in to work. At the middle cogs, the chain seems to skip and jump. I don't see any worn teeth with the cogs. I am using RD7800.
I am using a 8spd chain with the RD. Should it matter? I never had this problem until this morning.

John Montgomery
08-13-10, 12:02 PM
How old is the chain? That's my first guess -
|3iker
08-13-10, 12:06 PM
6mth old. ~ 1000km of use.

10 Wheels
08-13-10, 12:11 PM
Have you cleaned and lubed the chain?
|3iker
08-13-10, 12:23 PM
yes. every 1.5 mths.
cny-bikeman
08-13-10, 01:21 PM
It's imprtant to know if the chain is staying entirely on the gear when jumping or is instead starting to shift to another gear. If the former and the bike (not the chain) has a lot of miles on it, and you use those middle gears a lot then they have worn enough to skip (the wear is not always easy to see). It would seem unusual for it to show up suddenly, though, especially after months of using that chain.

If the latter, go through the full process of setting up the rear derailleur, including making sure cables are running smooth and clear. Any kind of misalignment of the derailleur or hanger can also cause "jumping" in some gears and not others.
|3iker
08-13-10, 02:19 PM
I think it could be the latter. As I've posted earlier, the bike & chain is not that old.