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How to Adjust Rear Derailleur on Mountain Bike? (5 Steps)

how to adjust rear derailleur on mountain bike

Your mountain bike will eventually not function as excellent as it used to. When this happens, you will experience difficulty in shifting gear or ‘ghost shifting,’ which can lead to a nasty crash. Upon checking your gears, the rear derailleur seems to be causing all these mishaps and requires adjustment.

But, how to adjust rear derailleur on mountain bike? Check out this guide to successfully adjust the rear derailleur on your mountain bike.

Things You Need for This Tutorial

mountain-bike-derailleur-adjustment

The process for mountain bike derailleur adjustment is pretty simple. You do not need any complicated tools. You just have to prepare a bike stand and a screwdriver.

Step-by-Step Guide to Adjust Rear Derailleur on Mountain Bike

adjust-mountain-bike-derailleur

Step 1: Adjusting the H-Limit Screw

Your derailleur comes with limit screws marked as ‘H’ for H-limit screw and ‘L’ for L-limit screw. It is important that you pick the H-limit screw when you adjust mountain bike derailleur. However, if there are no markings on your mountain bike limit screw, you have to pick one screw and turn it in and out.

adjust-shimano-rear-derailleur

Observe how the derailleur responds. If there is no movement on the MTB derailleur, you are picking the wrong screw. The screw that initiates the motion on your derailleur should be the H-Limit screw.

Upon identifying the H-Limit screw, get the right setting and tighten your adjustment of the limit screw. Move the screw until you notice that it is sitting nicely just right under the smallest cog. Using a screwdriver, tighten the said screw by turning it halfway.

Check whether you hear intolerable noise coming from the drivetrain by pedaling on your bike. If you can’t hear such noise, you have to tighten the limit screw even more. It is crucial that you hear the chain rub and hit the derailleur’s cog.

If you hear the sound, you have to back out the limit screw gradually until the noise ceases. If you hear no sound after the adjustment, you have adjusted the H-limit screw successfully.

Step 2: Tightening the cable

rear-derailleur-alignment

Now for the mtb derailleur adjustment, you need to turn the barrel adjuster clockwise twice. It is important that you move it back to its original position right before you make an adjustment to the limit screw. Choose the highest gear, which is the smallest sprocket on your MTB shifter.

Make sure that you pull the cable as tight as possible and fix it to the body through the cable anchor. Next, you need to select the third gear on your bike shifter and pedal forward until you notice a shift on the chain.

Inspect the position of the jockey wheel in relation to the cassette. It is important that the jockey wheel drive falls beneath the third bike sprocket.

Step 3: Adjusting the cable tension

install-a-rear-derailleur

With the help of the barrel adjuster, fine-tune the cable tension. Whether you need to adjust shimano rear derailleur, it is important that you turn the adjuster into a counter clockwise position in order to elevate tension on the cable. This will bring the derailleur closer to the bicycle wheel.

If you turn it clockwise, it reduces the tension and will move back to the bike frame. In case you notice that the chain seems difficult to shift up, you can increase the cable tension by moving the barrel adjuster into a counter clockwise direction.

However, if the chain skips over one gear, you have to reduce the tension and move the barrel adjuster to a clockwise direction. Notice the sound made by the drivetrain, if there is no noise coming from the train, you have set up the cable successfully.

Step 4: Shifting it up

adjust-front-derailleur

It crucial that you shift into the largest sprocket for the rear derailleur adjustment. Look for the screw marked L. You will normally see it just below the H-screw. This will show how far towards the wheel the rear derailleur will be able to move.

Ensure that you push the body of the rear derailleur as close to the bicycle wheel as possible. This will prevent the jockey wheel from moving further than the setting below your bike’s largest sprocket.

Make sure that you also turn the L-screw clockwise until the rear derailleur stops moving. It is one of the most essential steps, as it restricts the rear derailleur from getting tangled within the spokes.

Step 5: Adjusting the B-tension screw

mtb-derailleur-adjustment

The last step for the rear derailleur alignment is adjusting the B-tension screw. By this poinh, the bike chain is still on the largest sprocket. Make the necessary adjustment on the B-tension screw on the upper most part of the rear derailleur.

The tension screw will show how the upper jockey wheel can sit close to the bike cassette.

The jockey wheel must move close to the sprockets without even touching or rubbing them. If you turn the B-screw clockwise, the jockey wheel will automatically move away from the bicycle cassette.

You have to tweak it so that you can make a gap of around 3mm. At this point, you have successfully set your rear derailleur, and you can now ride the bike outside. Make sure that you observe how gear shifting goes. If it fails, maybe you need to re-adjust it, adjust front derailleur, or install a rear derailleur.

Conclusion

How to adjust rear derailleur on mountain bike is a complicated process for some. But if you familiarize yourself with the different components of a derailleur, it will be very simple.

There are major components you have to learn, like the position of the H-limit screw, the L-limit screw, barrel adjuster, and cable tension to adjust them. This is a repair skill that every mountain bike owner should have.

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