How to install and adjust a rear derailluer.

It is a good idea to install the bicycle rear derailluer first before the front derl. which will be then used to setup the latter. The same procedure is done if you want to tune up your rear derailluer.

Assuming that the chain is properly installed already.
(Also See Related Topic: Chain Installations & Shifter Cable Installations)

Step1.
After securing the rear derailluer on the hanger, shift the chain to the smallest cog. Look at the rear derailluer from the rear and turn the high-limit screw counterclockwise to move the chain away from the adjacent cog and clockwise to bring it closer, this avoid the chain from dropping out. Set the limit screw until the chain is not rubbing on the adjacent cog and the rear derailluer pulleys is aligned with the smallest cog where the chain is sitting. (see photo)

Step2.
While turning the pedal by hand push the rear derailluer inward on its side and see how far it can go. Turn the low-limit screw clockwise if the chain is over shifting and couterclockwise if the chain does not move up on the biggest cog. (see photo)

Step3.
Install the right shifter cable, turn the barrel adjusters all the way in (one located where the cable enters the rear derailleur and maybe another one on the downtube cable stop.), then attach the cable to the derailleur, pulling it taut to remove all slack (it is better to undo and reattach the cable to removed the slack and stretch the cable) While pedaling the bike, shift up one cog. If the chain moves to the next cog but hesitates or clatters, turn the barrel adjuster out (counterclockwise) one quarter turn. Shift back down, then shift up again and try another quarter-turn. Repeat until the shifting is smooth. Shift to all the cogs, If the chain misshifts when you go to larger cogs, turn the adjuster outward (counterclockwise). If it misshifts going to smaller cogs, turn the adjuster in (clockwise)

Step4.
Shift to the largest cog and looking from the rear again, check if the pulley is aligned with the cog. turn the low-limit screw counterclockwise until far enough to line up correctly or turn it back clockwise if overshifting when push inward by hand.

Tip: Clean rear derailleur every month or 20 hours of riding. Lube your chain lightly and wipe any excess. An over lubed chain will only invite dirt which than becomes like grinding compound on your drivetrain.

Enjoy
Rodge