Originally Posted by
Bike to Work
Hello,
I recently replaced my chain and rear cassette. I had also replaced the derailleur hanger as the previous one had gotten bent. After adjustments, there is no chain skipping on the rear cassette when the chain is on the large front ring, but it skips when it is on the small front ring. I made further adjustments on the barrel adjuster and B-screw. The skipping was reduced some but is still there. Is the small front chain ring the cause of the problem? Thanks for any advice.
Skipping may occur if your chain is too long and the rear derailleur is unable to take up the slack, but it works fine when the large front ring takes it up. Or your rear derailleur is bent and/or its hanger is not correctly aligned - which ring you're on determines the amount of slack and thereby the rotation of the cage, the angle at which the jockey wheel is inclined to the cassette and it's distance from the cassette.
Fiddling with adjusters may reduce the symptoms but you need to address the root of the problem.