Installed 12-14-17 Bikegang kit with end lug and Sunrace 3-speed friction shifter. Everything works fine and it shifts great but ran into this problem which seems strange. If I tighten the derailleur 15mm nut that holds the derailleur on more than hand tight, the underneath side of the derailleur hits the driver that holds the sprockets. So the driver rubs against the derailleur. For now I have it on hand tight but with two cone nuts, one acting as a jam nut so it can't come off. Since I did not alter the driver or the derailleur, I can't understand why this should be.