Originally Posted by
cyclotoine
Sometimes a new chain on a used cassette will skip a bit at first and then settle down. It's unlikely that the front derailleur could cause skipping. If you are using friction shifting it is possible that the rear derailleur wasn't quite trimmed correctly but it sounds like you have matching 7 speed indexed shifters to a 7 speed cassette? Or am I wrong. Where did you find the 7 speed bar-ends BTW? Another possibility is a worn out rear derailleur. if the pivots and bushing have become sloppy you can get a derailleur the sits on an angle and twists so that when you apply force the chain moves out of alignment with the cogs and causes it to skip. Pedaling lightly usually keeps it at bay.
I think what was happening was that the front derailleur was pushing lightly on the chain, causing it to skip at the chainring, rather than at the cassette. Like I said, it seems to have settled down since fiddling with the friction shifter...yesterday it wasn't skipping at all.
Come to think of it, the barends weren't Ultegra 3x7's, they were 3x8's, new. I also have a pair of used Suntour 3x7 barcons that I almost used, except they're kind of chewed up and ugly. I might use those on another bike.