Adjust The C-Screws On A Bike’s Rear Derailleur
The last adjustment on a rear derailleur is a C-screw. This screw presses on a small tag on the the back of the gear-hanger and adjusts the position in which the derailleur rests.
TheC-screw is sometimes called the ‘angle-of-dangle screw’. You don’t usually need to adjust it.