I have recently had chain suck issues on my winter training bike. It is a cheap Al cyclocross frame, with Avid BB7's, Mavic Speedcity wheels, and Centaur 10-spd ('06 vintage). Bike has worked very well for me, no breakage or other issues.

I have recently had bad chain suck issues when shifting from the big ring to small. All of a sudden, instead of RPM's increasing as I shift down, I just feel the crank freeze. It is a good thing this occurs normally when coasting up to a stop with minimal power application, otherwise, I probably would have already snapped the RD off. The two instances it occured I merely pedaled backwards and the chain released, then shifted properly upon pedaling again.

Why does this happen? There are not that many miles (~2500) on the chainrings that it should be worn, especially the 50-tooth one. Any suggestions? Bike has a compact FD, and shifting is excellent otherwise.

I am really worried that this will happen sometime when I am really putting the power down, and POW, lots of broken parts.

Cheers~