Originally Posted by cmillar87

Hi guys sorry to revive an old thread again but I'm having the exact same problem only my B screw is all the way in and the top of the derailleur cage is rubbing the largest cog when in the second to largest cog. The rubbing is just barely there but its enough where any back pedal motion snags the chain. The freewheel is a shimano 6 speed 14-28t and the derailleur is an older Shimano 105 short cage rd-1055. I tried a longer B screw to get more clearance but once the screw gets too long the angle changes and doesn't hit the tab. The bike is an 89 cannondale aluminum road bike it no hanger. Any thoughts would be greatly appreciated. I can post pictures as well but it's pretty much exactly as described. My only thoughts now how to remedy this are to buy another freewheel with a slightly smaller diameter cog on the large range like maybe a 24? Thanks very much.