One of the most frustrating and common problems you are likely to experience when riding a mountain bike is unresponsive gears. When this happens, you will not be able to shift gears which makes the bike difficult to ride. This also means that you won’t be able to control the speed or ride on hilly terrains. However, this is something you can easily fix without even taking the bike to a bike repair shop. Check out this guide to learn how to fix bike gears that won’t shift.
Why should you be concerned about bike gears?
Before we guide you on to fix bike gears that won’t shift, it is important you first understand how gears work.
Mostly a mountain bike has different gears according to the model. Most MTBs have 1, 3, 18, 21, 24 and 27 gears. For example, if the bike is labeled a 24-gear bike, it means that it has 24 gears. The low numbers represent low gears while the high number represents high gears. This means that the 1st gear is the lowest while the 24th is the highest gear.
All these gears are very important because they allow you to manage speed and they also allow you to climb hills or slopes more easily. The major reason why you can’t use a road bike on hilly terrains is that they do not have gears like mountain bikes.
When changing the gears, you should keep pedaling to keep the chain moving. This allows the derailleurs to move the bike chain from one sprocket to the other. The gears won’t change until you start pedaling.
Now that you know how bike gears work, let’s take a look at the tools you need to fix bike gears that won’t shift.
What tools do I need?
Make sure that you have the following tools before you start the process.
- A screwdriver
- A bike repair kit
- A bike cassette removal tool with chain whip
- A bike stand
- High quality bike tools
3 reasons why bike gears won’t shift
Chain problems
In case you experience shifting problems when using your MTB, the first thing you need to check is the chain because it is the part that connects the hub to the gears. Once it breaks, it will not be possible to move the bike forward.
One of the major reasons that might cause the chain to break is dust or dirt since they affect the movement of the chain. This is something you can prevent by using plastic wrap or covering it with a thick layer of grease. The plastic wrap ensures that dust doesn’t get into contact with the gears. If you decide to use plastic wrap, it is important also to wrap the entire chain with a flexible fine wire.
You also need to confirm that the cables are not under any pressure. Again, make sure that the derailleur is properly adjusted. When checking the chain, you need to ensure that there are no rusted kinks. Also, check if the gaps in the links are clogged.
Replacing a broken chain is not easy since you may need to disassemble the whole system. Therefore, it is advisable to invest in quality bike chains to minimize the chances of breakdowns.

Derailleur Problems
The derailleur is a highly precise and small pulley system that controls the shifting of gears. In case it is damaged or not working properly, you will experience problems when shifting. In case the gears are not moving at all, you need to check the cable that connects them to the derailleur.
This might also happen if the shifters are not well-positioned. To solve this problem, you should grease the chain. Start by wiping it with a clean cloth and then apply some bike lubricant to lubricate the chain and the links. Turn the wheels back and forth when applying the lubricant. If you find that the problem is a result of a malfunctioning or damaged derailleur, you should replace it.
Cable Problems
Another thing that might cause gears not to shift is the brake cables. When you pull the brake lever on the handlebar, the brake cables pull the cable which causes the bike to slow down. These cables contain two parts which include the housing and the inner wire. After some time, the cable’s housing may rust or they might become overstretched. They might also get damaged which means that you will need to replace them. In other instances, you may only need to clean them but when doing this, you should ensure that the housing ends, brake cable plus the metal cap that covers the housing ends are all clean. You can also use a reliable bike lubricant to clean the brake cables. Remember to apply a thin layer of coating.
If your bike or the cables are new, the gear cables are likely to stretch. You can use derailleurs to tighten or loosen the cables. You also need to ensure that the chain is well aligned.
Cable routing
The other thing you need to check is the routing of the gear cables. Turn the bars on either side and if they stretch, it means that they are not well routed. You need to re-route them to ensure that there is no tension on the cable once the handlebars are fully locked.
Conclusion
Before you hit the road with your mountain, bike, you need to ensure that the bike is in good condition. The gears are among the most important parts of a mountain bike and if they don’t shift, it means that you won’t be able to control speed or ride on hilly terrains. If you have been wondering how to fix bike gears that won’t shift, we hope that this guide has helped you on how to go about it.
Happy biking!