How To Install a Front Derailleur

Today we’ll learn how to replace a standard band-type clamp-on front derailleur. We’ll cover the E-Type bottom bracket mounted derailleurs in a future tutorial.
 

Tools

For this job you’ll need a 5mm hex key for the derailleur’s mounting bolt, and a phillips(+) screwdriver to adjust the derailleur’s limit screws and remove the derailleur cage bolt. If you are removing the chain you may need a chain tool depending on your type of chain. You’ll also need wire cutters and either a 9 or 10mm metric open end wrench or a 5 or 6mm hex key to remove and install the front shift cable.

Front Derailleur Removal

The first step is to shift your chain onto the smallest front chainring. Then pull off the shift cable’s end cap and loosen the cable pinch bolt. Remove the cable from the derailleur.
Now you’ll need to remove the chain from the derailleur. Some chains have a special connector pin that need replacing if removed, so if you don’t need to remove the chain for cleaning or replacement you can simply undo the derailleur cage’s tail screw and flex the cage open to release the chain. Rest the chain on the bottom bracket shell to keep it out of the way.
If you are removing the chain, disconnect a link and pull the chain through the derailleur cage. Now you can undo the derailleur’s mounting bolt all the way counter clockwise to remove the derailleur from the frame.

Front Derailleur Installation

Before installing the new front derailleur, apply some waterproof grease to the mounting bolt. Then place the clamp around the frame and tighten the mounting bolt just enough to keep it in place. At this point you still need to be able to move it by hand.
Now adjust the derailleur’s height and angle. For height adjustment, the bottom edge of the outside derailleur cage should sit approximately 2mm above the top of the teeth on the largest chainring. For the angle adjustment, rotate the derailleur until the cage is parallel with your chainrings. Then fully tighten the clamp’s mounting bolt.
If your chain is still on the bike, undo the tail screw on the derailleur cage and flex the cage to pull the chain through. Then re-install and tighten the tail screw again. If you have removed the chain, re-route the chain through the derailleur cage and reconnect it. Search the site for tutorials on how to use a chain tool or a quick release chain link.

Front Derailleur Set-up

Now preset the low-limit (L) screw so the small chainring appears halfway between the derailleur cage when viewed from above.
Thread the shift cable back into the derailleur, pull it tight and tighten the anchor bolt so the cable flattens. Then find a bare stretch of cable and give it a good pull to make sure the cable is seated and has no slack. Then loosen the cable, pull it tight again and re-tighten it.
Now you’re ready to adjust the front derailleur as shown in previous tutorials. If necessary, trim the cable so there is about 2 inches remaining. Then slide on a cable end cap and crimp it in place.