How to Adjust Front Derailleur on a Mountain Bike

How to Adjust Front Derailleur on a Mountain Bike

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Nothing’s more frustrating than an out-of-balance bicycle. We’ve all been there when, the front derailleur and chainrings no longer sync up to provide a crisp shifting sensation.

This is a common problem during the warmer months when dirt and debris from riding often get stuck in the gears. 

These tips can help you adjust your front derailleur setting without visiting a bike shop to get that crisp shifting back.

What is a Derailleur?

The derailleur is the device that connects the chain to the chainrings. Most shifting problems have to do with poorly adjusted derailleurs so there’s a good chance fixing the adjustment will solve your issues.

Key Takeaways

Most shifting problems are caused by issues with the derailleurs. The most common causes are incorrect positioning of the derailleur itself or loose limit screws.

Below I’ll explain how to fix both these problems.

Problem #1: The body of the derailleur is not positioned correctly

Step 1. Adjust the angle and height of the front derailleur

You can adjust the angle and height of the front derailleur to achieve a proper shifting mechanism. First, loosen the screw located at the front derailleur body with a hex wrench or an Allen wrench. 

Then, shift your bicycle fork so that it is in neutral position. Start by aligning your front wheel at the right height. If needed, you can flex the brake lever so that the front wheel is aligned with your handlebars. 

Raise or lower your front derailleur, until it becomes parallel to the back derailleur. You can do this by turning the screws that are found at its upper part.

Also, adjust its angle so that it is facing the correct direction. Next, tighten up both screws of your front derailleur after you’ve made adjustments on its position and height. 

Step 2. Make adjustment on its height through a positioning clamp

If you have a positioning clamp, make use of it by adjusting the height of your front derailleur. The positioning clamp, which is also known as the low clamp, will hold your front derailleur in place and increase its efficiency in shifting. 

To raise or lower the front derailleur, simply shift the screw upward or downward. If you decided to raise the height of your front derailleur, tighten up the screw so that it holds firmly in place. Now, loosen the screw on your rear derailleur.

When you are done, adjust the height of your front derailleur so that it is parallel to the back derailleur. You can do this by turning the screw located at its lower part.  

Step 3. Make use of a thumb lever

Another way to make minor adjustments is by using a thumb lever which is mounted to your handlebar. This will increase or decrease the angle of your front derailleur’s cage depending on how far you press it. 

Now, shift your bicycle chain into the lowest gear. Place it in the smallest chainring and smallest sprocket. Before you use your thumb lever, make sure that its bolt is tightened securely to avoid unscrewing it during shifting.

When you have made adjustments to the height and angle of your front derailleur, test whether or not it works before you come up with a final solution.

Do this by having somebody pedal for you, so that you can observe if the chain shifts properly from one chainring to another.

Problem # 2: The limit screws aren’t secured properly

Step 1. Make sure you set the inner limit screw. 

It is highly suggested that you shift the back derailleur to the highest gear possible. Then, position the chain on a large chainring and no sprocket. 

Next, loosen the inner limit screw located on your front derailleur’s upper part. Then, shift your bicycle chain to the smallest chainring and smallest sprocket.

Close your front derailleur by turning it back to normal position while applying some pressure on its shift lever.

Step 2. Check the adjustment of the outer limit screw. 

After you’ve finished adjusting the inner limit screw, shift your bicycle chain into any gear that has a large chainring and the smallest sprocket combination.

Now, pedal your bike to check if your front derailleur is working properly. If it is not shifting to its extreme position, align both limits by turning the screw located on the lower part of your front derailleur.  

Step 3. Make necessary adjustments

If both limit screws are properly adjusted, you shouldn’t be having any problem with your bicycle’s front derailleur.

But if the chain is still not shifting smoothly, make necessary adjustments on the front derailleur’s inner and out limit screws.

You should do this by turning them with a hex wrench or an Allen wrench until they are both perfectly aligned to one another. Take note that it will take practice before you can do it in no time and without much effort. 

Note: Adjusting limit screws should be done by someone who has advanced mechanical skills. It is not recommended that beginners to intermediate cyclists do this.

This will only set your bike off balance and it can cause a bigger problem like ruining the components of your bicycle. 

FAQs

How tight should the front derailleur cable be?

The front derailleur cable should be tight enough to decrease the chance of it snapping and shifting your bicycle chain at the same time.

A good reference is that if you feel that your hand is shaking when you are holding the shift lever, then it means that your front derailleur cable is too tight. 

But if you find it hard to shift into any gear or only have one gear available, then it means that your front derailleur cable is too loose. 

Should the front derailleur touch the chain?

No. The front derailleur should not touch the chain when shifting from one gear to another. If this is the case, then you will need to readjust your front derailleur and check if you are applying enough pressure while shifting gears.

Conclusion

The front derailleur is one of the most important parts of your bicycle. It will greatly affect how smoothly your bicycle will shift and handle its gears.

It can cause internal problems in the front derailleur, make it less efficient which can make it harder to shift gears, and it can even cause damage to other parts of your bicycle. 

So, if you are adept when it comes to working on bicycles with components like those in the front derailleur, then you shouldn’t have any problem adjusting them through this step guide.

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Written By

From riding to school since the age of 13, attending BMX races and events with his dad to himself conquering 50+ trails across the globe. For Rob, his Giant Stance 29 2 2020 is the friend that makes everything better. He is also a proud member of the International Mountain Bicycling Association (IMBA).

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