Ebike Motor Noise Under Load – Reasons and Fix

Choosing an Ebike over a regular bicycle means acheiving higher speeds with minimal effort. The whole point of having an electric bike is to have a hub motor for pedal assist. The harder you peddle, the higher the speed. But if the rear hub motor starts making loud grinding noises, the experience becomes less than ideal.

The noisy motor is a symptom of a faulty e-bike motor. That means the electric bike can stop running at any time. Causing you to lose control of the ride or, even worse, cause an accident.

Thankfully the problem is something that can be fixed. But before that, let’s find out what’s happening inside the motor. Let’s go

Why do you hear ebike motor noise under load?

e bike motor

It happens primarily because of a misaligned derailleur, dirty motor parts, or friction between the rotor and stator. 

Time to dig deeper into each topic:

  1. Misaligned Derrailluers: It actually might not be the motor. An e-bike with geared hub motor is a good example. The chain can skip or rub against something when the derailleur is not aligned correctly. That creates a grinding sound when you peddle hard. Also, very tight or very loose chain can cause this issue. If this is the case, the entire drivetrain needs to be fixed.
  1. Dirty Motor Parts: The rotor can’t move freely when the motor gets rusty or grimy inside. Thus, the friction increases among the motor parts, creating noise while the ebike is under load. However, the part that gets the rustiest is the opening of the rotor. Regular cleaning can help avoid this situation.
  1. Friction Between Parts: Another common issue I have seen is the friction between the motor parts. Inside a motor, there is a rotor and a stator around it. These parts can get displaced and rub against each other in some cases. This phenomenon is called “clogging.” And this friction between the rotor and stator can also cause unusual noise.
  2. Loose magnets: sometimes magnets in the motor become loose under stress; these need to be re-glued. This can be fixed by opening the motor, re-gluing the magnets, cleaning everything inside, and putting it back
  3. Striped Teeth of the Motor Gears: If the gears inside the motor look worn out, they will need to be replaced.

How to fix a noisy ebike motor

Whenever the motor starts making excessive noise, you need to fix it immediately. It’s not just about the annoying sound. It’s about the performance and safety of your electric bike. However, follow these below tips to fix a noisy electric bike motor.

Tip-1: Fix the motor

motor

Before checking the derailleur, fix the motor first. Otherwise, you will need to do it twice, which can be time-consuming. Anyways, go step by step to repair the motor.

Steps to Fix the motor

Disassemble

The very first step should be disassembling the motor. Turn off the bike and get a Screwdriver and start dismantling. Before that, you have to take the wheel off the bike. You can do it with an Adjustable Wrench. However, after taking the wheel off, remove the freewheel. Then, loosen the screws from the faceplate to open the motor.

Clean and reset

You can do minor cleaning when the rotor is on the bike. Just take a toothbrush and rub it with alcohol. However, taking the rotor off the wheel works better for precise cleaning and resetting. So, push the axle nut to remove the rotor.

Reinstallation

Lastly, reinstall the components. First of all, you have to close the motor. For that, place the faceplate correctly and then tighten all the screws. Now, reinstall the wheel. Set it on the bike and mount the freewheel. Then, insert all the bolts and washers, and you are all set.

Note: Disassemble and installation process can vary from bike to bike. Follow your bike manufacturer’s manual to do it correctly.

Tip-2: Adjust the derailleur

There is nothing special in adjusting the electric bike derailleur. it is similar to a typical road or mountain bike. Just a few things to remember here. For example, there is wiring through the freewheel. So, you have to make sure the cable doesn’t get damaged. Another thing is you have to remove the battery before doing the job. Otherwise, it can fall and get damaged.

Anyway, follow the below tips to adjust the derailleur.

  1. Turn the ebike off, remove the battery and hang it on a Bike Repair Stand.
  1. Diagnose the derailleur alignment. If the chain is straight and parallel to the cogs, then derailleur alignment is okay. Otherwise, it needs fine-tuning.
  1. To realign the derailleur, you need to adjust the limit screw setting. Tighten or loosen the limit screw and use the barrel adjuster until you achieve the ideal alignment. For advanced troubleshooting, you can follow my Rear Derailleur Adjustment guide.

How to maintain and care for ebike motor

How to fix noisy ebike motor

As they say, prevention is always better than cure. So here are some helpful tips on maintaining the motor:

  1. Keep it dry: Most of the time, water penetrates inside the motor and can cause rust. And rust can cause unwanted noise. So keep your electric bike from heavy water flow. Don’t use the pressure wash while cleaning the bike. Also, wipe the bike up immediately after a wash.
  2. Avoid lubrication:  most think lubrication will help to keep the motor parts from rusting. But in reality, it hampers the motor instead, as the lube attracts dirt and that causes issues. If you still want to lubricate the motor, apply silicon-based grease in optimal quantity.

Frequently Asked Questions About E-bike Motor

How long does an electric bike motor last?

It depends on how frequently you ride the bike. A good quality motor lasts for a long. It can last at least 10,000 miles. But, if you take well care of it and maintain it right, it will last even more. However, it’s good to maintain the motor every month and replace it after two or three years.

How often should an electric bike be serviced?

It depends on where and how you ride. As it’s a bit tricky to maintain an e-bike, a professional’s hands can do it better. Moreover, it will save a lot of your time. So, if you are okay with spending some money, it’s good to give the e-bike twice a year to a bike shop for servicing.

How often should I clean my eBike chain?

You can clean your e-bike chain as you clean the other bike’s chain. There is nothing exceptional to consider while cleaning the electric bike chain. Just make sure the motor doesn’t get wet. Avoid hosepipe or pressure wash for the washing job. However, I am telling you if you don’t know how often the chain should be clean. It’s good to wipe the chain up after every ride. Then, get a proper chain wash every month.

Conclusion

Along with the battery, the motor is essential to an electric bike. And biking with a noisy motor is not something we enjoy. I hope this post helped you diagnose and fix the problem.

Anyways, I hope you enjoy riding your electric bike.

Cheers!