I am having an issue with a chain riding up on the chainrings. Everything works great on the stand. However, when I get it on the road, the chain starts "dancing" across the lower stretch of chain between the lower pulley and the chainring. At first, I though it was a bent RD, but after I installed a new RD and the problem persisted I did some additional trouble-shooting. While on the stand, I started adding some resistance by manually pressing on the brake caliper and noticed that I could duplicate the problem. I noticed the chain starts riding up the chainring at the bottom of the rotation. Can some explain what is happening and suggest a remedy.

I'm wondering if I have a too-think, early generation chainring. However, the large ring is a pinned, later generation chainring which came with the crankset. Although the problem is not as pronounced in the big ring as the small ring, the chain does "dance" or ride up the back of the chainring on both the big or small ring.

I made a couple videos, which I hope I am successful in posting. The first is on the road and the second is the bike on the work stand (after a few seconds, I press the caliper and you can see the chain ride up the bottom of the chainring).

Lastly, the entire drivetrain (Campagnolo 9-speed chain, Chorus 9-speed cranks, Chorus 10-speed RD, Campagnolo 9-speed cassette) has fairly low miles, though it's been pieced together from various sources.

Thanks in advance.



http://vid850.photobucket.com/albums...ps6f9gp8ce.mp4



http://vid850.photobucket.com/albums...psb2iw9kev.mp4