The advent of e-bikes has gained ground so well that folks without a car seem not to feel the need to own a car. And most car owners who own an electric bike, are sometimes tempted to forget about their cars. It has taken the automobile landscape by storm. And just like car owners, e-bike owners often encounter technical problems as well, especially with the hub motor. If you are asking yourself questions about electric bike hub motor problems and how to fix them, here is the thing.
The rear hub motor, (which is mounted at the rear of the e-bike) generates the energy required to move the e-bike forward. Its potentials are fully operational when riding on hilly terrain and mountains. It’s rear positioning also gives the e-bike the force and stability to carry and transport loads. All of these factors combine to overwork the hub, causing it to malfunction from time to time. Furthermore, the hub motor oftentimes quickly overheats and fails to provide adequate support, affecting its off-road performance.
- The Hub Motor Recovers Energy (When Riding Down the Hill), Which Enables it to Recharge the Battery!
- The Hub Motor (Especially Rear Hub Motor), Releases Stress from the Chains and Lessens the Risk of Wear and Tear!
- The Rear Hub Motor Works Quietly and Peacefully!
- The Hub Motor is a Completely Independent Drive System!
- It is possible for regenerative braking!
So, when buying an e-bike, you should first determine what you want to use it for and the terrain on which you want to use it. This will give you an idea of the type of hub motor to opt for on your e-bike.
What Is Hub Motor?
Electric bikes are manufactured with two types of motors.
- The hub motor, and
- The mid-drive motor
E-bikes generally have their hub motor mounted to their wheel hub. Some e-bikes have their hub motor on their front wheels, while others have theirs on their rear wheels. And mid-drive motors are generally mounted with the e-bike pedals at the center of the e-bike. Most e-bikes with hub motors seem to lack balance, and it’s often difficult to change the tires. For this reason, most e-bikers love using the mid-drive motor due to its center position. But the hub motor is a bit advantageous because it is easy to replace, easy to maintain, and very affordable. Hub motors are very versatile for the manufacturing of electric bikes. A hub motor allows you to run the system and completely power your e-bike under the human drivetrain.
The geared type hub motor is lighter which makes e-bikes with them ride better and more efficiently on hilly terrain. While being known for their long-lasting lifespan, parts are less moving and can stand prolonged functions even at higher speeds.
Electric Bike Hub Motor Problems and How to Fix?
As an e-biker, there are numerous technical problems you may encounter with your e-bike. But let’s look at the few ones that have become commonplace in the cycling world and how to fix them.
1. Hub Motor No Longer Working
Let’s say you closed from work and on your way home, you noticed this noise on your e-bike hub motor (motor has already covered 600 miles). You don’t have any electric bike throttle problem, but any time you stopped and checked, the wires on the wheel were in order. You even tried checking the throttle and the e-bike motor ran for a while and then completely stopped. And from that point, each time you try to start the motor, not only it doesn’t run but it makes this disturbing electric bike motor noise. For that reason, you ended up pedaling the rest of your way back home.
How to Fix It?
If you have checked all the wires and you are sure nothing is frayed, then in one way or the other, there might be a problem with the hall sensor. In this case, you will have to do a hall test. To do so, you have to flip your hub motor backward. This is because the motor has a clutch that prevents the wheel from rotating the motor. And then plug the hub motor wires in and power it on. Find out if your electric bike motor spinning freely or it coggs. And then check to see if the motor also rotates freely or it coggs when the wires are unplugged. You can also check winding shorts using a multimeter. Also, check your wires carefully for possible shorting and disconnection.
2. E-Bike Wheels Unintentionally Locked up Partially
You pack your bike safely before going to bed. And the next morning on your way to work, you noticed that the wheels are partially locked up. You can spin the wheels with your hand but it is very difficult, and as you release your hands from the wheels, they stop rotating.
How to Fix It?
It could be a faulty controller. Each tick represents a magnet passing by. A magnet must have been unglued. The stator has a habit of pulling back into its slot each time you pull it out. The next time you take your hub motor apart, make sure you get a flat steel bar and use it against each one of the magnets. This way, you will be able to find out if anyone will be lifted out.
One cause of a motor short is that the wires become melted or destroyed at the axle. So, if disconnecting the controller somehow doesn’t free up the motor, don’t write it off right away. When a short occurs in a motor’s windings, it is usually fairly obvious, with the inside of the motor becoming black and stinky as the varnish cooks off the wire.
Anyway, try unplugging the controller and running some tests.
3. Geared Hub Motor Noisy & the Wheels Spin Only when There Is No Weight
You just noticed that when you sit on your newly purchased e-bike and push the throttle, the motor is running but the wheel is not rotating. When you take yourself off of the e-bike and lift it, the wheel rotates but with this noise. Even when you completely switch off the e-bike and try to move backward, it’s not rotating freely.
How to Fix It?
Such a problem should be at the level of the wires being pinched somewhere. This issue is commonplace, me inclusive. It could as well be a problem of melted wires or shorts, which causes resistance when trying to move your e-bike backward.
If that is the case, just like the case of partially locked up e-bike wheels, get a flat steel bar and use it against each one of the magnets. This will enable you to find out if anyone will be lifted out.
How Do You Test a Hub Motor?
How to test electric bike hub motor problems is something every e-biker must know. When testing an e-bike`s hub motor, you can take an overall look at the e-bike`s wiring. There may be issues like scrapes, cuts, missing insulations, etc. But generally, there are two principal electrical systems that you need to pay close attention to during the test. And these are –
- The hub motor winding (for high voltage)
- The hub motor`s hall sensors (for low voltage)
Motor Winding Test
Disconnect all phase wire leads from everything and test the level of resistance between every two phases at once. While testing, also compares the resistance of all the three phases combination. All three results from the tests must be the same. The low resistance reading can play on the accuracy of the test. But the most important factor here is not the readings, but they should be comparable. Overall, the readings can somehow be under 1 OHM. Thereafter, take a look at the resistance between every phase wire all at once, as well as a metal part of your hub motor. The reading should be infinity or even an open circuit.
Next, put together the two-phase wire and tie them in various combinations all at once for three tests altogether. At every combination, you should feel the same magnetic resistance (or cogging), each time you try turning the wheel. And when you separate all the wires, there should be zero resistance. If you are practicing this on a geared hub motor, to completely engage the motor, you have to turn the wheel in a reverse direction.
Motor Hall Sensor Test
The hall sensors of a BLDC motor determine the rotor`s position to ensure an accurate operation of the sensor type controller. Each of these hall sensors comes with three wires which need a voltage input of 5vdc, or 0vdc. while the last wire should be the output. This way, the harness wires will come to 5, RED=5vdc+, and BLACK=0vdc. And every one of the last three wires being the output of each circuit respectively. When the sensor is affected by the gauss of the motor’s magnet, the output voltage is switched from 5vdc – 0vdc. The controller uses this voltage which switches at the right time and order.
How Long Do E-Bike Hub Motors Last?
Most often when trying to purchase an e-bike, either for commuting or a pleasure ride, the question of longevity always comes to mind. The hub motor is usually the part of an e-bike that lasts longer than the rest. And with proper maintenance, it may even last more.
Let us find out how long an e-bike hub motor can last
The issue of e-bike`s hub motor`s lifespan is an issue without a straightforward answer over the internet. Because when you do a search on Google, Google will return a bunch of pages with a different lifespan ranging from 3000 to 10000 miles. These figures may be the case for some e-bikes but not for all due to the mark and brand of the hub motor, and the user base of your e-bike. A geared hub motor normally depreciates more quickly than a mid-drive hub motor, which is where the estimate of 3000 to 10000 miles comes from.
Mid-drive motors put more strain on the rest of your bike’s components. Before you replace the mid-drive hub motor, you may need to remove the chains, sprockets, and derailleurs. However, the mid-drive hub motor is more prone to overheating and rusting. This is completely against the 10,000-mile estimate. Various riders have claimed varying outcomes. Some customers have reported motor failure within the first 1,500 to 2,500 miles. Others have not claimed mileage, rather they have reported riding their bikes for more than three years. This demonstrates that our mileage varies.
For example, you would cover 12,775 miles if you are riding a 35-mile range e-bike at its maximum range daily for one year. That’s significantly more than the standard e-bike motor’s 10,000-mile rating. This isn’t outright proof of anything; it’s just something to think about.
From all we have seen so far, we can qualify the lifespan estimate of e-bikes hub motor between 3000 to 10000 as a reasonable range. But in the nutshell, the lifespan of your e-bike`s hub motor will depend on your personal management and the mark of your hub motor.
The major cause of a motor problem is an electric bike controller faults, since the controller is the lifeblood of an e-bike, sending energy from the battery to the motor. However, as the market evolves, so too does the expertise. With all the servicing issues that users are encountering, the expertise in all areas of e-bike upkeep is growing, which will lead to better maintenance of these machines.
Hello, this is Evan Larry. The chief editor of this site, “eBikeBuster.” After completing my graduation in mechanical engineering, I worked for a renowned e-bike manufacturing company as a technician. I had worked there for almost six years, and later I quit the job and started my own business where I sell different types of e-bike and their tools and accessories. I created this site, eBikeBuster, to guide people, who are new to an e-bike and don’t have proper knowledge about its tools, accessories, and maintenance.