Adjusting the front derailleur correctly requires precision down to the millimeter scale. If you're having trouble shifting gears, or your bike chain is rubbing against the derailleur, you don't need to go to a bike shop to have it fixed. All you need is simple equipment and a keen eye. With practice and patience, you can become proficient.
Step
Method 1 of 2: Fixing the Gearshift Problem
Step 1. Know how a properly adjusted front derailleur should look
Your goal is to position the front derailleur securely over the chain with the outer plate 2 – 3 millimeters above the largest chainring (bike front tooth). This way, the derailleur arch will be parallel to the chainrings and chain. Do not ride the bicycle if the derailleur rubs against the chainrings or gets caught in something. We recommend that you head over to the Reset section below.
Step 2. Diagnose the problem with your bike
Turn your bike upside down with the saddle and handlebars down. Raise and lower the front derailleur while turning the pedals with your hands. Can the chain shift to all gears? Is there a clicking, rubbing, or snapping sound? Record and remember any problems that occurred while you were doing the setup.
- Use a bicycle stand if you have one as it will be very helpful.
- The rear derailleur needs to be adjusted properly before proceeding, check if the derailleur does not move properly.
Step 3. Shift to a low gear position
Make sure that the chain is in position middle cog (back teeth) and smallest chain ring to keep the chain from crossing and the derailleur cable to loosen, making it easy to adjust.
Step 4. Loosen the cable retaining bolt and tighten the cable derailleur
Above the derailleur is a thin cable held in place with bolts or screws, usually attached to the bicycle frame. Hold the top of the cable and pull it up, then loosen the bolt. Pull the cable tight, then tighten the bolt again. The bolts will keep the cable from moving.
The derailleur will move a little, but you'll soon be setting it up again. Now make sure the derailleur cable is tight so that everything can function normally
Step 5. Locate the limiting screw
There are two small screws on the top or side of the derailleur which are marked with the letters L and H. Both appear to be untightened and slightly protruding from the derailleur. These two screws are the Low and High limiters, which control how far the derailleur moves to the right or to the left. Both can be adjusted with a + screwdriver.
- The L screw controls how far the derailleur moves inward, while the H screw controls how far the derailleur moves outward.
- If the limiting screws are not marked, you can easily identify them. Move to the smallest chainring. Turn one of the screws fully in both directions while looking at the derailleur. If it moves, then this screw is an L screw, if not, try the other screw. After that, mark it with the letter L.
Step 6. Set the gear low on your derailleur
Shift to the smallest chainring and rear gear to the largest cog so that the chain position is on the left. Turn the screw L until there is a gap of 2-3 mm between the derailleur and the chain.
The derailleur will move when you turn the screw
Step 7. Set the gear high on your derailleur
Turn the pedal and shift the front gear to the largest chainring position and the rear gear to the smallest cog. The chain will be on the outer part of the bike. Turn the H screw until the derailleur is 2-3mm away from the chain so that it has enough room to move.
Step 8. Shift the rear gear to the middle cog, then try shifting the front gear
Shift the rear gear to the center size cog so the chain doesn't pull when shifting gears. Turn the pedal and shift the front gear up and down, making sure there are no obstacles when shifting. Adjust the L and H screws to taste, and happy cycling.
If you turn the L and H screws too much, the derailleur will move too far and the chain will come loose. However, you can find out before you try cycling
Method 2 of 2: Resetting the Broken Derailleur
Step 1. Reset the derailleur if it hits the chainring, bends, or tilts
The retaining bolts will only help if the derailleur needs adjustment. If you feel the derailleur hitting the chainrings, pay attention to whether the derailleur is tilted, or too high. You have to reset the derailleur from scratch.
Step 2. Shift gears to the leftmost chainring
Shift gears to the smallest chainring at the front and the largest cog at the rear. It's a good idea to place the bike on a stand or tip the bike over to make it easier to turn the pedals and change gears.
Step 3. Loosen the barrel adjuster to reduce cable tension
The barrel adjuster is at the end of your derailleur cable, close to the handlebars. Follow the front derailleur cable to the small, rotatable cylindrical section, then turn it clockwise.
Count how many times you spin the barrel. You'll then return it to the same position when you're done
Step 4. Loosen the derailleur cable securing bolts
There is a cable that runs above the derailleur to the shifter (gear shift lever). The cable is held in place with bolts so that it does not move or shift. Loosen this bolt enough to allow it to move when pulled, but not enough to come out on its own.
Step 5. Carefully loosen the derailleur retaining bolts on the bicycle frame
Don't let the derailleur move too far, as it can change your entire setup. Loosen the bolts sufficiently so that you can wiggle and shift the position of the derailleur.
Step 6. Slowly move the derailleur to the correct position
If the derailleur is tilted, rotate it until it is parallel to the chain, being careful not to change the height of the derailleur. If the derailleur touches the top of the chainring, raise it a few millimeters above the largest ring. Your goal is to:
- The derailleur is 1-3 mm above the largest chainring. Adjust the distance between the outer plate of the derailleur and the chainrings to the thickness of a coin.
- The two derailleur plates are parallel to the chain.
- The bend of the derailleur corresponds to the curve of the cog.
Step 7. Reset the cable and limiting bolts
After the reset is complete, you will need to reset the derailleur to function normally. Pull the cable tight and clamp it back with the bolt. After that, re-adjust the limiting bolts as described in Step 1.
- Always lubricate and clean your chain for perfect shifting.
- Make sure you have tightened the barrel adjuster
Tips
- Use pliers to make it easier for you to pull the cable tight.
- Take each step slowly, then tighten it all up and give it a try. Do not move or twist the bolt excessively as it will make it difficult for you to return to the previous setting if something goes wrong.
