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If you have challenges shifting gear, using the gear you want, or the chain getting off the bike, then you need to adjust the gears. Shifting issues can damage your bike or cause accidents.
What’s more, constant clicking as you pedal, inconsistent shift, or gears changing themselves from one cog to another, is a sign that you need to adjust the gears.
Derailleurs are parts of the gear system that allows you to change gears every time you shift. Unless they are checked well and corrected, you will still have problems with shifting gears.
Adjusting bike gears is not that difficult. With patience and practice, this is a skill that you can learn. In this article, we’ll discuss the best way you can adjust bike gears. Let’s get started.
Three Reasons Why You Are Having Problems Shifting Gears
Before you adjust your bike gears, first, you need to check the following to ensure that your bike is in the right conditions before making any changes:
Sometimes the problem can be in the chain. Remember that the rollers and pins of the chain do wear down with every ride. They wear down more quickly, especially if you are riding in bad weather conditions.
What happens is the wear lengthens each link making the chain wear. Riding on a worn-out chain makes the cassette and chainring’s teeth wear down further.
That’s why it is advisable to check your chain often and replace it when you can. Otherwise, you are at risk of replacing the whole drivetrain.
If you are riding your bike and the chain keeps falling off any time you shift gears, you need to check the chain wear. You can start by checking the chain using a chain checker tool. If your chain is OK, then chances are, you have the following two problems.
Damaged Housing or Cable
Damage cables or housing can cause shifting problems. First, check the gears’ housing, from the front to the shifting levers and back to the derailleur.
If the housing has an extreme bend or pinches, it could be restricting the movement when you shift the gears. In case you spot any damage, replace the housing and the cable.
What’s more, if you notice any frayed cables, you need to replace them. Remember that a bike with internal cable routing could have issues inside the frame you are not seeing.
If you want to diagnose the problem seriously, you may need to replace the cable and housing.
Damaged Derailleur Hanger
A damaged or bent derailleur can cause shifting issues and make your chain come off. This can even cause more problems like broken spokes or derailleur.
The derailleur has a soft metal that can bend or get damaged easily. If you fall off the bike or your bike falls, sometimes it’s vital to check the condition of the derailleur hanger before you can adjust its gears.
An ordinary derailleur hanger needs to be parallel with the cogs in the cassette. Any slight bend or twist sign that you will have shifting issues if you ride the bike. You can only rectify the problem using a derailleur hanger alignment gauge. With this tool, you bend back the derailleur to the correct position.
Tools You Need To Adjust Bicycle Gears
If, after checking the chain wear, cable, housing, and derailleur hanger, you find no problem, then you need to adjust the derailleur. In this section, there are three basic adjustments that you will need to make to fix the challenges you have. Here are the tools you will need to get started:
Adjusting the rear derailleur
The rear derailleur has a limit screw that prevents it from moving too far and making sure the chain won’t come off the cassette. If the chain comes off, it can cause a wedge between the cassette and the wheel, causing damage.
The derailleur has both the high (H) and low (L) limit screw, which limits it at the end of the cassette.
How to set the high limit on the rear derailleur
- Step 1: Shift the gear into the smallest ring cog
- Step 2: Use the Allen key to undo the cable retaining bolt.
- Step 3: Turn the cranks by hand and slowly slacken the high screw by turning it anticlockwise until you hear the chain making noise.
- Step 4: Tighten the H screw and only stop when you can’t hear more noises. If you hear the noise again, turn it anticlockwise.
How to set the low limit on the rear derailleur
- Step 1: Start by turning the cranks by hand and pushing the derailleur into the 2nd largest cog ring.
- Step 2: Stop the cranks and wheel from turning.
- Step 3: Push the derailleur to the largest cog ring without turning the cranks
- Step 4: Using your hands, turn the wheel while you hold the derailleur. If the derailleur catches the spoke, then you need to turn the low (L) limit screw clockwise until you leave it with 2-3mm clearance.
- Step 5: When the derailleur is clear of spokes, push it towards the largest cog while turning the cranks.
- Step 6: If the chain doesn’t go to the largest cog, but the derailleur is close to the spokes, chances are, the derailleur is bent. What that means is, you may need to buy a new derailleur for your bike.
- Step 7: When the chain goes into the largest cog and makes noises, you may need to tighten the L screw until the noise stops.
When you have the upper and lower limits set, the next thing is clamping the cable back and adjusting the tension. That way, you will leave the rear gears indexed well.
Adjusting The Front Derailleur
Once you have adjusted the rear derailleur, adjusting the front derailleur won’t be a challenge. Here you will require the same tools I mentioned above and your patience.
The height of the chain cage needs to be set between one to three millimeters. If you are installing a new derailleur, it will come with a guide on how to do it.
When you are setting the derailleur, make sure the chain cage is parallel with the chainring. Like the rear derailleur, the front derailleur will have a pair of limit screws for high and low gears.
The L screw is for adjusting the smallest chainring, while the H screws are for adjusting the largest chainring.
If the front derailleur doesn’t have the marks to identify the L and H, you may want to turn each of them one at a time with your hand. The screw which makes the derailleur move is always the L screw.
How to set a low limit on the front derailleur
- Step 1: Shift the front and rear gears into the lowest gears. Start rotating the cranks until the chain moves into the inner chainring. If the chain refuses to move, you may need to turn the L screw anticlockwise until it moves.
- Step 2: Make sure you undo the cable retailing the bolt on the derailleur
- Step 3: Using a screw, adjust the L screw until the chain is positioned well in the middle between the chain cage side plates.
How to set a high limit on the front derailleur
- Step 1: Put the gear on the smallest ring on the cassette
- Step 2: Unscrew the cable retaining the bolt
- Step 3: Turn the cranks using your hands while holding the derailleur and make sure the gear is on the large chainring.
- Step 4: Start slackening the high (H) screw by turning it anticlockwise. Continue doing that until you hear the chain making the sound while rubbing against the chain cage’s outer plate.
- Step 5: Tighten the H screw up until you can’t hear the noise. And that’s how you set the high limit on the front derailleur.
One thing that separates the front from the rear derailleur is that it lacks a barrel adjuster. What that means is, you have to work with the adjuster on the shifter. If you have a road bike, you will have inline barrel adjusters on the bike. However, if you lack one, you can buy and fit it into your bike.
When you are shifting gears on the front derailleur, remember to change gears at the rear. Don’t cross-chain gears from the largest ring to the largest cog at the end.
Likewise, never cross-chain gears from the smallest ring to the smallest cog at the rear in the process. Doing so can damage the gear system or cause wear and tear on the chain.
Gears are essential in a bike. There’s nothing more frustrating than fighting with gears on your bike. Adjusting your bike gears well will reward you with excellent cadence and a smooth ride. Most importantly, you will enjoy riding the bike.
If you have shifting issues with your bike, you can follow the guide above and adjust the gears correctly. It may seem not very easy at first, but you will learn and get used to changing the gears with a bit of patience.