When riding a bike, nothing is as frustrating as trying to change gears but they won’t shift. Every rider deserves a smooth-running transmission for a splendid biking experience.
You try to upshift to increase your speed or downshift to slow down, but nothing seems to work. Instead, you only hear a clicking sound as the chain jumps up and down on the rear cassette.
Sometimes you have to shift up or down past a gear and then back to it again to set your desired speed.
In a worst-case scenario, the chain might derail from the teeth of the gears, throwing you off balance and off the trail.
The good news is that you do not have to be mechanically experienced to fix bike gears that won’t shift.
With the help of this guide, you will learn how to adjust bike gears that won’t shift and discover ways to prevent this problem from happening again.
Here is how to fix bike gears that won't shift:
- Re-Index your gears.
- Straighten bent hangers.
- Adjust derailleur limit screws.
- Clean your cable and cable housing.
- Replace worn out chains.
- Adjust the length of the cable housing.
- Lubricate the gear system.
- File ragged housing edges.
- Replace frame with a new set.
- Avoid using excess power when shifting gears.
What Causes Bike Gears Not To Shift?
The issues causing bike gears not to shift are many and they vary in complexity depending on the type of bike you have. However, no gear shifting problem is too big for the ordinary rider to fix so long as you know its root cause.
Here, we discuss the possible reasons your bike gears are not shifting as desired.
1. Worn Out or Damaged Chain
Chain problems are among the most common reasons your gears are not shifting. If you’ve been riding your bike for a while, it is highly likely that the chain is worn-out because of normal tear and wear. This will make smooth shifting of gears almost impossible.
2. Clogged Drivetrain
The drivetrain of a bicycle comprises several components, including the pedals, chain, cranks, cogs, chain rings and derailleur. If excess dust and dirt accumulates in the drivetrain, it will become hard for the gears to function optimally. A filthy drivetrain is not only sluggish to shift but also more likely to wear out quickly.
3. Poor Cable Adjustment
Correct cable tension can make all the difference in ensuring the gears of your bike shift as smoothly as possible. However, maintaining optimum cable tension is difficult since you have to find the right balance to ensure the cable is not too tight nor too loose.
4. Loose Derailleur, Cassette or a Bent Hanger
A loose derailleur, cassette or a bent hanger could also prevent your bike from shifting gears correctly. The derailleur and hanger should align correctly for smooth transmission. You should also make sure all these components are tight and the wheel is sitting in the ideal position.
5. Kinks or Pins in the Cable Housing
If your bike trails involve riding off-road in the bush and other non-tarmacked terrains, there’s a high chance the cable housing could have picked up sticks and grit along the way. This might interfere with how the gears work. Inspect the cable housing for these and remove them accordingly.
6. Worn Out Cable Housing
Another reason your shifting might be erratic is because of a worn out cable housing. The worn out housing will cause friction over time, leading to many problems. The rugged edges of the housing could interfere with and impede the cable leading to sluggish shifting.
7. Inconsistent Cable Housing Length
In case you didn’t know, the length of the cable housing is of utmost importance as it determines shift quality and consistency. If the housing is too long, it will cause needless friction to your shifting.
Conversely, if the housing is too short, it will affect cable tension, making it almost impossible to shift gears smoothly.
8. Poor Frame Design
Would you believe it if we told you that a poor frame design could impede your gears from shifting? This is particularly true for older version bikes.
Older bikes have slippery and internally routed frames with cables running through multiple awkward angles. These frames cause excessive cable friction thus leading to shifting problems.
9. Excess Power When Shifting Gears
Sometimes, problems with shifting are not on the configuration of the bike human error. You could be pedaling too hard and shifting gears with too much power resulting in a sluggish shift and damage of components.
Steps To Fix Gears That Won’t Shift
Now that you know about the causes of gear shifting problems, it’s time to learn how to fix them. In this section, we look at some of the most effective ways of fixing bike gears that won’t shift.
Here are the steps:
1. Re-Index Your Gears
When your gears won’t shift up or down due to loose (stretched) cables, you need to re-index your gears.
Indexing bike gears is not as daunting as it seems. Your bike comes with a barrel adjuster and you just need to turn this adjuster counterclockwise to increase cable tension.
Here’s a short video on how to index your gears:
2. Straighten Bent Hangers
If your gears are indexed properly, but you are still having trouble with your shift, then check out the hanger. It should be straight, but because of damage and normal tear and wear, that’s not always the case. This could impede your shifting. Straighten the bent hanger or replace it immediately.
3. Adjust Derailleur Limit Screws
Your gears might not be shifting because of a poorly set up derailleur. You can tell the derailleur is not properly set if the chain keeps on dropping off either end of the chain rings or cassette. To fix this, adjust the limit screws to increase tension.
4. Clean Your Cable and Cable Housing
When cleaning your bike do not forget to wipe off the dust and debris from the cable housing. Debris-buildup and dust can clog your drivetrain and cause issues with shifting. Use a spray degreaser if you are having a hard time cleaning the cable housing.
5. Replace Worn Out Chains
If your chain is jumping, slipping and constantly misbehaving when you’re trying to shift gears, then perhaps it’s high you considered replacing it. You don’t need any special tools to know that your chain is worn out and needs replacing.
6. Adjust the Length of the Cable Housing
The length of the cable housing determines shifting quality and consistency. If the housing is too long, it will cause so much friction. If it’s too short, your gears won’t shift properly because of too much tension.
7. Lubricate the Gear System
Most modern bikes do not require lubrication. However, poor lubrication is one reason why your gears are not shifting appropriately. Applying a thin layer of lube can go a long way to ensure your bike shifts gears smoothly and silently.
8. File Ragged Housing Edges
The cable housing can have ragged edges for a variety of reasons.These rough edges will impede the chain and cause issues with shifting. To avoid this, file the rough edges or replace the housing entirely.
9. Replace Frame With a New Set
Older bikes comprise internally routed frames where the chain passes through queer angles. This increases the likelihood of the chain jamming and the gears stalling. If the design of the frame is the issue, you have no choice but to replace it with a newer frame that has an improved cable routing.
10. Avoid Using Excess Power When Shifting Gears
Sometimes the solution is as easy as using less power when cycling and shifting gears. Learn when to click the shifters correctly into place. You should ease up on the power you exert when pedaling to avoid problems when actuating a shift.
Tips on Tuning and Maintaining Bike Gears
Most bikers do not consider maintaining the gears of their bikes a priority. Some feel the process is complex while others choose to ignore it.
The secret to silent and smooth transmissions lies on how you tune and maintain the gears of your bike. Here are a few tips to consider:
- Clean your bicycle regularly—focusing on the chain, gears and chain housing.
- Replacing worn out components immediately.
- Replace cables four times every year.
- Ensure the derailleur hanger is straight and the wheels are tightly in place.
- Adjust the tension to the chain and align it accordingly.
- Check and adjust the length of the cable housing optimally—to find the right balance.
- Always inspect your chain and chain housing for clogs, pins and kinks.
- Apply bicycle-specific lubrication to a clean chain.
Riding a bicycle that won’t shift gears can be a horrible experience. You need a heart of steel to handle this predicament effectively. Thankfully, by following our guide on how to fix bike gears that won't shift, you can fix your bike in no time. The best part is that you don’t even need mechanical experience to do it. Try one of these tips and let us know how it goes.