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The electric bike motor is the basic piece that represents the core of the electric bike, and without it, your bike cannot be called electric.
Despite the importance of this piece, it is known that it is not easily to get damaged and its lifespan may range from 20,000 miles to 50,000 depending on the power and type of the motor, as the design of the hub motor is considered to have a relatively longer lifespan than the mid-drive.
Although this information is considered good news for us electric bike riders, the presence of noise coming from the motor is considered very bad news.
The reason for this is that the presence of noise means that there is damage to one of the components of the motor, and here the matter is completely subject to luck.
If the noise is caused by parts that can be repaired or not
Therefore, in this post, I will explain to you all the reasons for hearing a noise from your electric bicycle motor, and also explain what can be repaired and when you should decide to buy a new motor.
Now lets Get started.
Normal VS Abnormal Noise.
Before we get into the practical part of solving motor problems, I should first explain to you the difference between normal and abnormal noise produced by your e-bike motor.
Normal noise is the result of the movement of the motor, which is mostly the result of the movement of the internal parts.
The strength of this noise varies depending on the design and strength of the motor.
For example, a hub motor does not emit a loud noise compared to the noise coming out of a mid-drive motor.
Now you may ask,
How do I know whether the noise coming from the motor is normal or not?
Based on my personal experience, normal noise is composed of only one sound, which increases or decreases according to the speed of rotation of the motor
As for the abnormal noise, it is caused by two different sounds, and it is loud in the first, and as the motor is wound quickly, it begins to gradually decrease.
Why is my ebike motor making a noise?
As a general rule the reasons why e-bike motors make noise are:
- Gears and gearboxes issue
- Damage Bearing or lake of greasing
- Misaligned stator magnet ring
- ebike controller issue
- Chain rattling noise
- Loose bolts or nuts
- Spokes loose
After we mentioned the most common reasons that cause noise from the motor, we will explain how to fix each of the previous reasons.
Note: The previous reasons are arranged from most difficult to easiest
1-Motor Noise that caused by Gears issues.
The noise resulting from a problem with the gears is a sound of metal friction, the sound is louder at slow speeds than at high speeds.
To be more precise, the reasons that lead to this sound in the gears are either the ring gear slipping or the intermediate gears are damaged.
The solution to this problem depends on the extent of the damage to the gears.
If the problem is the ring gear, you will need to have it drilled and pinned. If the intermediate gears are damaged, they will need to be replaced
however In this case, I recommend changing the motor completely, and this is for two reasons
- The first is that the cost will be very high, very close to the price of a new motor.
- The second is that the bike’s performance will be less than it was.
2-Motor Noise that caused by Damage Bearing or lake of greasing.
The sound of noise resulting from a problem in damage bearing or lake of greasing is a sharp metal or plastic friction sound, the sound is low in pitch at slow speeds and the pitch increases with the increase in motor movement
In order to solve this problem, you must open the motor (we will explain the method in the next section) and check the bearings. If they are broken, they must be replaced.
But if it is intact, it should use a large amount of lithium grease to help in reducing friction
You must also make sure that the bearing are tightened well and correctly
3-Misaligned stator magnet ring.
The electric bike motor works by electromagnetic force and is surrounded by poles of magnets called the magnet ring. All magnet poles must be organized in the form of a circle of equal height.
If any of the magnet poles move out of place, there will be a metal friction noise and also a decrease in the motor’s response.
We will explain this method in a pictorial manner because it will also help you understand how you can open your bike’s motor
Step 1: flip your ebike and remove the chain.
Step 2: Using Allen key remove all screws of the motor.
Step 3: After opening the motor you will notice that some magnet are moved up.
Step 4: Using small screw push the magnet back to its original place.
Step 5: using super glue try to put some small drops in the gabs between the magnet to avoid repeating the issue.
Step 6: wait for 1 hour till the glue dry then close the motor.
4-Motor noise that caused due to ebike controller issue.
Sometimes the motor noise is caused by a problem with the controller and not with the motor. This problem often occurs after maintaining the bike or installing a new controller.
The sound of this noise is like a thin ringing, and the motor often does not move or moves backwards
In this case, you will need to test the controller or perform a reset so that it once again recognizes the motor and turns in the correct direction.
We explained how to reset and test the controller in previous posts, which you can view here:
3 Proven Techniques for Testing Ebike Controller at Home
Resetting Ebike Controller | Full Guide
5-Chain rattling noise.
The noise may be due to the electric bike chain not being in the right place or not being tied well, which causes the feeling that the sound may be coming from the motor (especially if you have a mid-drive).
In this case, you can check the sound of the motor by using the throttle only.
If the sound disappears, the problem is with the chain. so you should lubricate it & place it in the correct position.
6-Loose bolts or nuts.
The role of the external screws and nuts in the motor is to ensure that the two parts of the motor are well connected to each other.
If some of the screws are loose, there will be a hollow noise while the motor is moving.
The solution here is to check the screws and make sure they are intact first, then tighten them well.
7-Spokes loose
If you have a hub motor, you have certainly had the experience of having one or more spokes loose
This is common in electric bicycles that have a hub motor because the weight of the motor is on the rear wheel and the motor is fixed on it using the Spokes
In this case there will be wobbling at the rear wheel with some ringing noise
The solution in this case is to tighten the Spokes well and make sure how fast the motor is on the front or rear wheel
Can you reduce the motor sound?
If we explain the causes of noise from the motor, you may ask if there is any way to reduce the sound of the motor. In fact, you will not be able to reduce the sound of the motor, but you can maintain the original sound of the motor through good maintenance.
If you want to get very little sound, your best option is a hub motor made from international brands that have motors that operate very quietly.
Conclusion.
In order to summarize what came in the post, we will mention the problem, the type of noise, and the solution in the next table
| Ebike Motor Noise reason | Ebike Motor Noise type | FIX |
| Gears and gearboxes issue | sound of metal friction | If the problem is the ring gear, you will need to have it drilled and pinned. If the intermediate gears are damaged, they will need to be replaced |
| Damage Bearing or lake of greasing | A sharp metal or plastic friction sound | Replace or use a large amount of lithium grease |
| Misaligned stator magnet ring | Metal friction noise and also a decrease in the motor’s response. | Reposition magnets & glue it |
| ebike controller issue | Thin ringing, and the motor often does not move or moves backwards | Test & rest ebike controller |
| Chain rattling noise | Rattling noise | lubricate the chain & place it in the correct position |
| Loose bolts or nuts | A hollow noise while the motor is moving | check the screws and tighten them well. |
| Spokes loose | Wobbling at the rear wheel with some ringing noise | tighten the Spokes |
