wierd derailleur problem

ddraver

hey guys

I have this problem with a SRAM X.9 read rerailleur on newish XT cassette and old crankset (Knackared BB) using a SRAM crosslink chain

Usually but not always at low chain tension times, the chain appears to lock in the derailleur, often when i'm about to put the power down, this pulls the derailleur forward untill i stop pedalling, If i'm going fast enough i can backpedal about a quater of a turn and it will free up and be fine until it does it again

the jockey wheels are not in tip top condition but i though i'd check if that was the problem?!

many Thanks

DaveK

mattv

Checked for a stiff link in the chain?

Rockhopper

Hooked tooth on the chainset not letting the chain go perhaps.