So, the front derailleur of your bike seems stuck. You tried fumbling with the limit screws once or twice, but no luck.
Now you must be wondering:
What to do when limit screws not moving front derailleur?
To solve this problem, first you need to know the exact way to limit screw settings. Twisting the screws clockwise, you need to adjust the limit screws to the front derailleur. It will ensure the movement. Work on the settings of inner stop and outer stop separately to get the best outcome.
We completely understand if you are still confused. But don’t worry. Because, in this article, we’ve answered how you can easily ensure the movement of the front derailleur.
Keep reading to find out!
Why Does Limit Screws Not Move Front Derailleur?
There can be a few reasons why limit screws restrict front derailleur movement. As in it’s stuck in a place and won’t operate. Here are some possible reasons:
- The mechanism might be containing any dirt or grime that is interrupting the movement.
- There can be an error in the limit screw settings.
- The adjustments of limit screws with the front derailleur are not done correctly.
- There might be an issue with inner and outer stop settings.
Some of the above reasons are responsible for limit screws not moving rear derailleur.
How to Solve the Problem of Limit Screws Not Moving Front Derailleur?
Getting rid of the stuck front derailleur is not that difficult of a job. You just need to know the right way and follow a few things. Starting from the exact way of setting up the limit screw to the front derailleur adjustments.
Here’s a detailed snapshot of the things you should do:
Limit Screw Settings
Limit screws usually halt any inward or outward expedition of the front derailleur cage. They’re marked H and L.
The job of the L-screw is to stop the movement of the derailleur. It prevents its going toward the small chainring. The H-screw helps halt the movement of the derailleur to the biggest chainring.
Sometimes you may find no markings in the high and low limit screws. In that case you need to distinguish which one is “H” and which one is “L”. You can do it by testing.
Start with the chain that is on the tiniest cog. Loosen up the cable tension entirely. For that you can use a cable barrel adjuster.
Place one hand on top of the derailleur body and try to get a feel. Look for any sidewards movement. Then select a screw to swerve a full turn clockwise first.
Then twist it again but this time counter-clockwise.
In this process if you could feel any motion in that derailleur, that indicates the L screw.
If no motion is found, you need to do the exact test with another limit screw. Then try to permanently mark the L screw. So, by default, the other one is surely H screw.
The limit screws should halt the derailleur. It’s the wire that is inside that creates any kind of motion in the derailleur. The derailleur spring does the same as well.
If that inner wire includes extreme tension, the derailleur isn’t going to lay on the L-screw stop.
The tension of the inner wire could change sometimes. If so, the inner limit of the derailleur is also supposed to change. However, it will probably cause the chain to topple over the rings.
Front Derailleur Limit Screws Adjustments
So you’re facing the issue of limit screw not moving front derailleur high. Or maybe no movement of front derailleur. Remember all of these are caused by poorly adjusted limit screws.
The case of the derailleur swings side to side from the derailleur body. It happens in reaction to the shift commands.
Also, it transmits the chain from one chainring to the other. It should move back and forth within a very precise range for it to perform adequately.
Limit screws mainly control this back and forth movement of the front derailleur. It applies for both the inner and the outer border of the derailleur.
These tiny screws are normally placed next to each other on the central front derailleur body. They are either assembled horizontally or placed side by side. Each of these screws regulates one pinnacle of that derailleur’s movement.
The screw in the outer stop determines up to the point distance. The distance that the derailleur may transit away from the main frame. The screw in the inner stop infers how crowded that derailleur may transit toward the frame.
If you turn the screws clockwise it will limit the outward range of derailleur. If the chain is springing off the ends of the chainrings or maybe the outer cassette. That is the only time you should swivel those screws clockwise.
However, Twisting those screws counterclockwise can enable the derailleur to gain more range. Plus, throw on its outer limits as well.
Nevertheless, you really need to tune those two limit screws properly. If you can do that, the front derailleur will operate without difficulties.
Take a peek at some of our top picks for Shimano front derailleur:
These derailleurs can also be used alongside other brakes, using an adapter.
Inner Stop Setting
To tune the front derailleur, first you have to detect how far it moves toward the frame. For that, you have to change the position of the front derailleur towards the innermost chainring.
Then you need to allow the tension to come out of the front derailleur cable. You can do this by loosening small bolts that anchor cables with the derailleur body.
Loosening the cable is going to ensure that the arm is unrestricted. Also that it’s free to swing as far off as it can go.
After that, you have to shift the chain to its furthest position inside. That is the neatest chainring as well as the biggest rear cog.
Use the inner limit screw for positioning the inner wall of the front derailleur cage. Make sure that there’s 2 mm of clearance in between.
Also, try to maintain the same distance for the chain. Especially at those points where the chains may come closest together.
Once you are done setting the inner stop, you need to yank the derailleur cable taut. And then re-anchor it steadfastly. Do this task when the chain is on the small chainring.
In case you’re struggling with adjustments, you should check out guides on front derailleur cable.
Outer Stop Setting
After you’re done setting the inner stop, you need to shift the chain to its farthermost position. It refers to the biggest chainring as well as the tiniest rear cog.
Properly position the outer face of the front derailleur cage using the outer limit screw. The derailleur cage needs to be in about 2 mm distance from the outward surface of the chain. That’s that point where the chains come closest.
It’s the derailleur cage that helps keep the chain from going past the outward most chainring. And thus prevents it from falling off the bike. Always remember while making the adjustment.
Many shifting systems can not automatically move the derailleur out as farthest as possible. In terms of shifting towards the biggest chainring. This is true especially for the newer ones.
So, you need to pull on the front derailleur outward a bit, not rear derailleur. Do this when you set and assess the adjustments of the outer limit.
The amplified cable tension is going to confirm that your derailleur is actually in its outermost status. Also, the chain can’t tumble down.
How do you reset limit screws?
To reset the limit screws, first, turn both of the limit screws out. Next, position the derailleur with both the highest and lowest gear. Maintain the sequence respectively. Then twist the screw associated with it in each case. Don’t stop until you notice it reaching its designated area of the plate.
How to adjust the front derailleur to the right height?
Loosen the bolt that is clasping it to frame. Then rotate it to the proper position. Notice when it’s above the larger chainring. The outer edge of the derailleur must sit 2 mm above the chainring. If needed, trudge it to and fro and tighten the bolt again.
How to fine-tune the front derailleur?
For this you need to shift through the gears using a barrel adjuster. Turn it anti-clockwise and you will notice it increasing the tension. Thus shifting it to the large chainring more easily.
We hope we have cleared your confusion about why limit screws not moving front derailleur?
One added tip, before you go all- mechanic, just check your front derailleur. Look for any grime and dirt that’s perhaps interrupting the movement.
That’s all for now. Have a good day!