Common Mountain Bike Problems, Causes, and Solutions
Mountain bikes are prone to specific problems as much as any other sporting equipment. The type of problems a mountain bike will develop depends on critical factors like how it is being used, where it is being used, the type of mountain bike, and the maintenance habits of the rider. It is best to be familiar with common mountain bike problems, the causes, and their solutions.
Common mountain bike problems are a jammed chain, gear jumping, a broken chain, a skipping chain, clunking sounds, stiffness in the bike chain, a misaligned chain, and a slipped derailleur.
Your mountain bike will develop certain issues depending on the type of bike, as well as how you use and maintain it, but some problems are common to all mountain bikes. As a rider, it is crucial to know the more common MTB problems, what causes them, and how to solve these issues.
Mountain Bike Chain Problems
A bicycle chain is a roller chain that transfers power from the pedals to the drivetrain of a bicycle. Bike chains move continuously, rotating around the gears of a bike. This movement is what propels the bicycle forward. A chain that doesn't move smoothly will make pedaling difficult.
The most common mountain bike chain problems include a jammed bike chain, a slipping bike chain, a broken bike chain, a chain that skips gears, a stiff chain, a misaligned chain, and a clunking sound coming from the chain.
Your mountain bike chain is in constant contact with the drivetrain, which can cause a lot of friction. As this article from the Journal of Mechanical Design Explains, friction results in energy loss, inefficient pedaling, and wear on the drivetrain which can cause it to break. The other most common problems your bike chain will develop, as well as the causes and the solutions, are discussed below.
1. Jammed Mountain Bike Chain
You have a jammed mountain bike chain when your chain cannot move through the bike's gears as you pedal. This can happen as you ride your bike. A chain jamming is a common issue you can easily fix. A jammed mountain bike chain happens when your bike's chain gets stuck within the cassettes of your rear gear and the derailleur.
The root cause of a jammed bike chain includes insufficient lubricant like this on the bike chain or a poorly aligned derailleur. Which can be fixed with a derailleur alignment tool like this. The solution to a jammed bike chain is to carefully untangle the chain from the gear and fix it back properly onto the cassette. You can read our step-by-step guide on how to untangle a bike chain.
2. Mountain Bike Chain Slipping
A bike chain slips when it doesn’t remain on the selected cog and slides off the rockets without the rider changing gears. This can cause a sudden jolt which could distract the rider and cause them to lose control of the bike. As this Bicycle Safety Report from The Department of Transportation explains, chain-related accidents are one of the most common causes of bicycle accidents.
The major causes of chain slipping include a worn-out or loose chain, worn-out cassette teeth, extreme lubing of chain, a dirty chain or gear system, and a rear derailleur that is not well aligned. Our article about how to fix a chain that is too loose will help you figure out if your chain is too long and how to fix it.
The solution to your chain slipping is determined by what is causing the slipping. It is better to change a worn-out chain with one like this, and a cassette with one like this. This thread on StackExchange discusses when you should change your bike’s cassette. Clean your bike chain and gears with a kit like this as often as possible. Also, ensure the chain is well aligned with the derailleur.
3. Broken Mountain Bike Chain
When your bike chain is broken, your bike becomes unusable. Your bike chain is responsible for transferring power from the pedals to the drive train. Without the bike chain, your mountain bike is useless
Chain breakage on bikes is common and some reasons why a mountain bike chain breaks include a worn-out cassette, a worn-out chain, a chain that is too short and tight, or the chain that shifts under an extreme load. Our article about how to fix a chain that keeps breaking will give you some ideas on ways to troubleshoot this pesky problem as well as methods to avoid it.
To fix a mountain bike chain that keeps breaking, first remove the broken link in the chain. Then reconnect the chain using a master link or a pin. Tools needed for fixing a broken bike chain include a chain tool from a set like this, a chain link, a replacement chain, and high-quality chain lube. Our ultimate list of tools for mountain bike maintenance could be a great resource for you to figure out what tools you will need.
4. Skipping Mountain Bike Chain
Your bike chain skips when it jumps between gears, shifts twice while you are riding, or refuses to shift when you change gears. There are several reasons why your bike chain skips and if you would like to know more have a look at our article that discusses how to fix a mountain bike chain that's jumping or skipping gears.
The core cause of a skipping bike chain includes worn-out or loose chains, worn-out teeth of cassettes and cogs, dirt chains and gear systems, faulty gear cables, or a derailleur that is not well aligned. It is better to change a worn-out or loose chain first as this is the least expensive repair. Ensure that your chain is well aligned with the derailleur and properly fitted onto the rear and front gear. Clean and lubricate your bike chain and gears often to reduce wear.
5. Stiff Bike Chain
A stiff bike chain will stick and click with every rotation. It cannot roll freely around the bike gears, and you need to apply a lot of force to your pedals for your bike to move. A major cause of stiffness in a chain is poor maintenance of the bike chain, especially when not in use. Another cause of stiffness in a chain is rust. A chain should not be left to rust, and several chain lubes like this one provide rust protection.
The solution to a stiff chain is evidently to properly maintain it by cleaning and lubing it. We explain this in our quick steps to clean a mountain bike chain properly and lube it to reduce the chances of it becoming stiff. If you will not be using the bike for a while, it is good practice to clean the gear system as often as possible instead of leaving it to rust in the garage.
6. Misaligned Chain
The symptoms of a misaligned chain include chain jumping, slipping, and— in extreme cases—getting jammed in the gear system. You will often hear the clanking sound of the bike chain as you ride the bike.
The primary cause of a misaligned chain is when the chain does not fit correctly on the gear sprockets. Another reason is using the wrong size chain ring on your bike, making it hard for the chain to fit perfectly. Other causes include inappropriately placed spacers and the use of incorrect-sized sprockets.
The solution to a misaligned chainring is to get a professional to align your chainring properly. Watch this video tutorial by Park Tool on how to route your chain correctly in your bike.
7. Clunking Sound
When you hear a clunking sound from your bike as you ride it or change gear, you might need to check the crank of your bike. This sound is often followed by the inability of the chain to move to the next gear.
The primary cause of a clunking sound is a loose crank. This can happen from riding the bike on rough terrain. There is also the rare case of the crank not being properly fixed. To eliminate the clunking sound, you have to tighten the crank correctly to the lower bracket of the bike.
You may also be interested in learning if a mountain bike chain guide is worth it. Be sure to check out our related article to find out more.
Summary of Mountain Bike Problems Related to Chains
| Symptoms of Mountain Bike Chain Problems | Causes | Solution | Useful Products |
| Jammed Mountain Bike Chain | Occurs when your bike's chain gets stuck in the cassette of the rear gear and the derailleur | Skillfully and gently untangle the chain from the gear and fit it back properly | ReHook Color |
| Mountain Bike Chain Slipping | Worn out or loose chain and cassette teeth. | Change worn-out chain and cassette. | Park Tool SK-4 - Home Mechanic Starter Kit |
| Broken Mountain Bike Chain | Worn-out cassette, a worn-out chain | Change link | Masterlink |
| Skipping Mountain Bike Chain | Worn out or loose chains | Change worn-out or loose chain. | Chain tool and Masterlink |
| Stiffness in Bike Chain | Chain is rusted and dirty | Properly maintain it by cleaning and lubing | Muc Off Dry Lube and Degreaser |
| Misaligned Chain | The chain is not aligned correctly with the gear. | Align chain | Chaintool |
| Clunking Sound | A clunking sound is the result of a loose crank | Tighten the crank. | Crank Wrench |
Mountain Bike Gear Problems
A mountain bike gear is an essential part of a bike drivetrain. Bike gears determine the relation between the speed of the revolution of a bike crank, the rate at which the rider pedals, and the rate at which the drive wheel turns.
The most common problems a bike gear can develop include gear jumping, slipped derailleur, and cable problems. There is friction between the components of a mountain bike gear system during shifting and pedaling. This can wear down the sprockets. Regular gear maintenance can reduce these problems.
We will discuss several mountain bike gear problems you might have to deal with alongside the causes and the solutions to each one.
1. Mountain Bike Gear Jumping
Gear jumping occurs when the chain skips between gears when a rider changes the gear. Gear jumping is a common issue with bike gears. When a gear jumps, it makes riding difficult.
The core cause of a skipping bike chain includes worn-out teeth of cassettes and cogs, and chainrings. These are important parts of the gear system of a bike and when they are not properly maintained, it affects the gear in several ways one of which is gear jumping. Our article about how to clean bike gears gives steps on how to maintain the gears so that they don’t jump when riding.
Another solution to fix a jumping bike gear is to change the worn-out cassette or chain ring with something like this. The earlier this issue is solved, the better because if left unchecked, it can cause further damage to the gear.
2. Slipping Derailleur
A derailleur like this is a device that changes gears by moving the chain from one sprocket to another. The derailleur also holds the excess chain when the chain is moved to the smallest cassette. A slipping derailleur cannot properly shift a chain from one cog to another so the bike chain slips off when a new gear is selected, which can make riding unpleasant.
The major cause of a slipping derailleur includes incorrect adjustment and the use of a bent or damaged derailleur. Oftentimes, the problem can be with the chain or the cogs too.
To fix a slipping gear, properly adjust the derailleur. A bent or broken derailleur might have to be replaced. You should also make sure your chain is properly aligned with the derailleur. These videos by Park Tool show how to adjust a rear derailleur and a front derailleur.
3. Faulty Gear Cables
Gear cables are comprised of an inner cable made of twisted steel wire that runs through an outer sleeve from your bike’s control levers on the bar to the derailleurs. Our article about what to do when a mountain bike grip shifter is stuck illustrates how this common problem is often the result of dirty or damaged gear cables.
Gear cables develop faults when they become old, too stretched, or worn out. A faulty gear cable means you will not be able to control certain parts of your gears, like the derailleur from the bike control levers as you ride. You cannot shift gears on your bike with a faulty gear cable.
The solution to faulty gear cables is to change them. Replacing gear cables isn’t difficult but it can take a few hours to do. This video tutorial from Global Mountain Bike Network, explains how to remove the old cables and cable housing, as well as how to reinstall new cables.
Summary of Mountain Bike Problems Related to Gears
| Symptoms of Mountain Bike Gear Problems | Causes | Solution | Useful Products |
| Gear Jumping | Worn-out teeth of cassettes, cogs, and chainrings | Change the worn-out or loose cassettes, cog, or chain ring. | Cassette removal tool kit |
| Slipping Derailleur | Old gear cables | Change gear cables | Complete Bike Brake Cable Housing Kit for Mountain Bike, Road Bike |
| Faulty Gear Cables | Old and worn out Gear cables | The solution to faulty gear cables is to change them | Complete Bike Brake Cable Housing Kit for Mountain Bike, Road Bike |
Mountain Bike Brake Problems
A bicycle brake is a crucial part of a bike. It is used to reduce the speed of a bike. Responsive brakes not only allow the rider to slow down to navigate difficult trails, but they are most important when the rider needs to stop immediately. Faulty brakes put the rider in danger.
The most common mountain bike brake problems include poor engagement, break rubbing, and bike squeals. These are problems that arise from poor maintenance of the braking system and misaligned brake calipers.
We shall discuss the several problems bike brakes are prone to, their causes, and most importantly, the solution. Arming yourself with knowledge about a bike’s braking system will help you diagnose issues before they become serious safety problems. You can check out Woombike’s detailed list of bike brake problems and step-by-step instructions on how to solve them.
1. Poor Engagement
The symptom of poor brake engagement on a bike can be recognized when you tug on the lever and realize the brake pads are not effectively making contact with the wheel rim. This can be dangerous as a bike brake with poor engagement means you are prone to bike accidents.
There are two primary causes of poor engagement in your bike brake. The first is usually because of a poor connection between the brake cable and the lever. The second reason is that the brake "noodle" is not correctly seated in the brake channel.
You can solve poor engagement in a bike brake by ensuring that the brake cables are correctly fitted into the brake lever when they are connected. Also, ensure that the brake noodle is correctly seated in the brake channel.
2. Brake Rubbing
Another major problem associated with bike breaks is break rubbing. Brake rubbing occurs when the brake pads touch the rims of your wheel without you applying the brakes. Brake rubbing can cause a sudden reduction in your bike's speed as you ride, and can make pedaling difficult.
The causes of brake rubbing can vary. Some of the more common causes include a poorly aligned wheel and a stuck lever. If your wheel is not well aligned, the side to which it tilts will keep contacting the brake pad. Also, when your lever gets stuck when you apply it, your brake pad will remain engaged.
The solution to break rubbing involves aligning your wheel. Scrutinize your wheel to make sure it isn't wobbling. If found wobbling, loosen the quick release, ensure the axle is seated correctly in the drop-outs, and re-tighten the quick release. This assures that the wheel is centered and will often solve your brake rub issue. In the case of a brake lever getting stuck, change the brake lever.
3. Bike Squeals
Bike squeal is the ear-piercing noise from your bike when you apply your brakes. Bike squeals make riding uncomfortable as the noise will disturb your focus. This problem is one of the most common problems with bikes. This paper from Delft University of Technology investigates the common causes of bike squeals and how to reduce their occurrence.
The major cause of bike squeal is the presence of dirt and small stones in your bike’s brake pads and rims. The terrain on which you ride your bike often determines how often dirt gets stuck to the brake pads and rim. There is also the chance that the surface of your bike pad is not even. So when they grip on the wheel rim, the friction causes a lot of noise.
Clean your bike frequently. The frequency is determined by the terrain you ride on, the dirtier and muddier the trails you ride, the more often you’ll need to clean your bike. The solution to bike squeals is proper maintenance of your bike. Also, ensure your brake pads are correctly installed. Improperly installed brake pads often have their surfaces worn out unevenly.
Summary of Mountain Bike Problems Related to Brakes
| Symptoms of Mountain Bike Brake Problems | Causes | Solution | Useful Products |
| Poor Engagement | Poor connection between the brake cable and the lever, and brake "noodle" not correctly seated in the brake channel. | Properly fit brake gear | Complete Bike Brake Cable Housing Kit for Mountain Bike, Road Bike |
| Brake Rubbing | Poorly aligned wheel and a stuck lever | Align your wheel | Mountain Bike MTB Repair Tool Kit |
| Bike Squeals | Presence of dirt and small stones in your bike pad and rims. | Frequently clean your bike pad | Bicycle Disc Brake Cleaner |
Mountain Bike too Small or Other Size Problems
Using the wrong size mountain bike is inefficient. Whether too big or too small, when you use the wrong size bike, you feel the negative effect on your body and on your riding experience.
If a mountain bike is too small, it can lead to the knees hitting the handlebars, back pain from riding, struggling in tight corners, and poor bike aerodynamics. Riding a small bike makes it difficult to control and puts the rider at risk.
Our mountain bike sizing chart and our article that explains what mountain bike you should buy, are handy resources to help you choose the right one. Also, our guide to mountain bike seat dropper repair might be something you might be interested in learning more about.
1. Knees Hitting the Handlebars
If your knees hit the handlebars of your bike as you ride, or you find it hard to properly adjust your knees as you pedal without the handlebars interfering, your bike is too small.
A bike your size should comfortably accommodate your knee movement. The frame should be long enough that your legs have enough room to rotate freely as you cycle.
2. Back Pain From Riding Your Bike
Back pain from riding is common. Some of the reasons why you might get back pain from riding a mountain bike include riding on rough terrain, arching of the back, and poor posture. Our article about where to hold mountain bike grips to maintain better posture has helpful tips to reduce back pain.
However, if while you ride your bike, you notice your posture is compromised merely so that you can fit on your bike, then your bike is too small. According to this article by ChiroCare of Florida, a chiropractic institution in Florida, incorrect riding posture can cause back pain for riders.
3. Struggling In Tight Corners
Do you find it challenging to get your bike around tight corners? Do you struggle to make sharp turns without first dropping your legs to support your weight? If your bike is too small, these are a few challenges you will face as you ride.
A small bike doesn't offer the balance needed for flexible and efficient riding. The biggest challenge as you ride a small bike would be how to properly control the handlebar and pedals without having to stop consistently to maintain balance.
4. Poor Bike Aerodynamics
If there is a large amount of seat-post showing on your bike as you ride, chances are your bike is too small. A high seat post means your seat post is adjusted to its maximum height. While it is not bad to have a lot of seat-post showing, it can impact the bike's aerodynamics.
Most modern bikes are built to reduce drag from airflow (aerodynamics). Your seat position is a major factor in reducing drag. Once your seat post is extended to the highest level, you add to the amount of drag your bike will have to overcome from flowing air.