So, yesterday I picked up a second-hand Tifosi CK7. It came with a Shimano 105 5600 groupset in the triple chainset configuaration and a with medium cage derailleur.
THE PROBLEM IS that when the chain is shifted into the middle or small chainrings, the upper pulley wheel of the derailleur rubs against the cassette, making a fairly loud rambling noise when turning.
Of course, my immediate thought was to adjust the b-screw, but this is already maxed out. One observation I made is that while in the small chainring, the chain tension is really low, causing the chain to sag notably. I’m not sure whether shortening the chain alone will resolve the issue though.
Any advise?
Thanks,
Pete