Derailleur Adjustments

This easy repair can be performed in just a few minutes if you complete the task correctly. We have arranged a list in chronological order for task completion.

Tools Needed: 5mm Allen Wrench or 9mm open-end wrench, Phillips screw driver, pliers and bike stand.

Rear Derailleur

• Put bike in stand.
• Put chain in middle-ring and smallest cog in the rear.
• Turn barrel adjuster on the rear derailleur and shifter all the way in (clockwise) to loosen the cable tension. The adjusters are located at the end of the cable housing on the back of the derailleur and at the other end on the shifter. Again, this will loosen the cable tension.

• Loosen the cable-anchor bolt with the Allen wrench or open-end wrench (see picture, 1A.).

• You must now use your adjusting screws (See Picture:2A). These DO NOT AFFECT cable tension directly. They are what defines the "range" the derailleur will move within (See Picture:2B).

NOTE* If your adjusting screws are not labeled, you will have to determine which one adjusts which function by trial and error. When you turn the "H" screw you can actually see the derailleur move. If you are turning the screw and nothing is happening then you are turning the "L" screw.

• The "H" screw will stop the derailleur from dropping down too far (past your smallest cog) and the "L" screw will keep the derailleur from shifting into your spokes (past your largest cog).
• Now, adjust the "H" adjusting screw (it should be labeled and stands for high gear). This is accomplished by pedaling and making sure the derailleur pulleys are properly aligned with the last cog (smallest cog).Turning the "L" screw clockwise will cause the derailleur to move up towards larger gears.
• Now, with the pliers, grab the end of the cable and pull the slack out of the cable and re-tighten the anchor bolt.
• Shift up one gear to see if the chain moves from the small cog to the next bigger cog. If it does not move up a gear, it means that there is still too much slack in the wire and you need to fine tune it with the adjusting barrel. Turn this to the left (counter-clockwise) to increase the tension on the cable.
• Shift again, does it go up a gear now?
• Keep using the barrel adjuster to fine tune the cable tension. Remember, turning it to the left will help the derailleur move up a gear, turning the adjuster to the right will loosen the tension and make the derailleur not travel as far.
• Now, you must adjust the "L" adjusting screw(should be labeled and stands for low gear) (picture:A). This is the biggest cog in the rear cluster.
• Shift slowly and pedal so that the chain moves into your biggest cog.
• If you cannot get the chain to go into this cog it means that the "L" screw is stopping it from going into this gear. Loosen (counterclockwise) the "L" screw until it allows for the chain to go into this gear. NOTE: YOU WANT THIS ADJUSTMENT TO BE PRECISE SO THAT YOU NEVER SHIFT YOUR CHAIN INTO THE SPOKES. ADJUST IT SO THAT IF THE "L" SCREW WAS ANY TIGHTER THE CHAIN WOULD NOT GO INTO YOUR BIGGEST COG. This is your final adjustment.
• If your chain makes it into the biggest cog, then you need to lock the setting down by tightening (Clockwise) the "L" screw until you feel the screw hit the derailleur. You want this adjustment to be performed precisely like mentioned above. Just enough for the chain to make it into the biggest cog if you have this adjustment too loose you will shift into your spokes.
• Ride

DISCLAIMER: Please understand that by working on your own bike you are taking responsibility for the adjustments. Most adjustments require expert service and the descriptions above are written for reading purposes only and are not factory directions. Bikeparts.com claims no responsibility for any adjustments made by the reader and recommends that you take your bike to a shop for proper adjustment.