The popularity of electric bikes is growing in leaps and bounds in the United States and around the world, and for good reason. Electric bikes or e-bikes are faster, more efficient, and safe for the environment.
Furthermore, there’s also a wide range of electric bike sizes, styles, and motor speeds, which makes it easier to find one within your budget.
Apart from the many benefits of owning and using an electric bike, some issues need to be addressed from time to time. Electric bike hub motor problems are one of them.
Electric Bike Hub Motor
A hub-drive eBike has the motor conveniently located inside the wheel hub, either on the front or back wheel. The engine propels the vehicle forward by rotating the tire to which it is attached.
A hub motor eBike may not navigate naturally for certain riders; depending on whether it has a motor on the front or back wheel, the eBike may feel like it is being pushed or dragged.
An inexperienced rider may face difficulties as a result, either because the greater weight in the front wheel makes steering difficult or because the additional weight in the back wheel makes it harder to balance.
The motor for a mid-drive eBike is located at the bottom bracket of the bicycle, just between the pedals. This guarantees a low and central centre of gravity, balancing the weight, and a typical bike-like riding experience. Because of its placement, the motor’s added weight is not felt by the riders, offering mid-drive eBikes excellent directional and tracking stability.
The improved gears make it possible for more prolonged riding, which riders can’t see but will feel on a long ride, especially on hills. Similar to a car’s engine, electric motors want to spin quickly.
The motor in between the pedals is turning at an efficient rpm as the user changes gears to pedal at a natural bike-riding cadence (usually 50–100 rpm). Bosch only uses mid-drive motors due to these factors.
A hub-drive eBike’s motor powers the wheel, which on a steep climb can spin quite slowly. When a motor is rotating slowly and the rider is using the hub motor heavily, it may occasionally overheat, resulting in either a permanent shut-off or irreversible damage to the magnets within.
The hub motor making a whining, grinding, rattling, or banging noise means it needs to be checked out before it turns into something serious.
Any of a number of problems might be the cause, and to check some of the components, you will need to open the hub cover. Ball bearing problems, loose parts, or gear lubrication are some issues that may arise in the hub motor.
Remove the gear hub/motor cover for a quick fix by raising the electric bike on its kickstand. Rotate the rear wheel to hear the sound coming from different directions. If the noise is coming from the gears, they must be greased. If the sound is coming from a loose magnet, epoxy must be used to reattach it.
Hub motor noise is one of the frequent problems with electric bikes. If the motor’s bearings, disc brake, or gears are worn out, this problem frequently occurs. Such noises can occasionally also be caused by a loose bolt.
The issue can be resolved by replacing the worn-out component, but if it still occurs, the motor bearings likely require lubrication and the noises are caused by friction.
An electric bike hub motor is a better choice than an electric bike mid-drive system for most people who are new to electric bikes or would want a casual rider. Cost is the main factor.
You could spend over $1000 on an e-bike conversion kit with a mid-drive motor, or you could spend about $250 on a high-quality hub motor kit, most of which cost under $300.
Another factor is the weight distribution and handling advantages of a hub motor versus a mid-drive arrangement. A standard hub motor weighs roughly 2 pounds, but depending on the technology you choose; an e-bike mid-drive can weigh up to 16 pounds.
Hub Motor Stopped Spinning
The hub motor’s ability to cease spinning is a common issue. This usually means that there is a controller issue. The engine may not be receiving power to start because of a loose connection or a total lack of connection.
Check your controller’s functionality and connection to the motor to resolve this problem. Replace any broken controller or wire components right away.
The E-bike may occasionally experience significant vibrations and strains that might cause some loose connections, which could either make the E-bike function improperly or leave it entirely useless. Due to these problems, it is advised that anybody with reasonable intellectual capacity occasionally inspect the exterior wiring of the E-bike.
Another improved bike maintenance method is having regular maintenance inspections performed by maintenance professionals. If the maintenance requirements are not properly attended to, the problem can wind up getting worse rather than better.
Check the Hall Sensor
The hall sensors are located within a hub-style motor. The rotor, a wheel of magnets that rotates with the stator, is located using hall sensors. This setup guarantees precise controller functioning. There are three wires and a voltage input required for each hall sensor.
The motor controller won’t synchronize with the energy transmitted by the motor if these sensors stop working. This is why an instrument called a multimeter is required to test the hall sensors.
A multimeter is a tiny electric probe that typically has two connected leads and prongs at the end. By turning on the hall sensor with a DC battery, putting the prongs to the sensor to produce a readout, and comparing the readout to the rated voltage, you may use these prongs to test the voltage of your hall sensor.
Typically, if one of the hub motor’s hall sensors is destroyed, you will hear a vibrating noise without seeing any movement from the motor. The tremendous heat created by the motor, which may exceed the temperature that the sensor can endure, is the primary factor that causes damage to the hall sensors in the hub motor. Thus, it is always advisable to purchase hall sensors designed to tolerate high temperatures.
Using a multimeter to gauge each sensor’s voltage is the initial testing method, which is also the least expensive. While the motor is operating, the reading must either be positive or zero to indicate that the sensor is functioning.
Depending on which magnet is opposite to this sensor, for instance, you may observe a positive reading on the multimeter when you begin the measurement but a zero reading when the motor is rotating.
The reading must remain the same. Thus, if it is 4, it must stay that way every time. However, if you see that the positive reading is 4, 5, or 2, this is a sign that the sensor is damaged.
Hub Motor Overheating
The heating of the wheel hub motor can also be caused by inadequate or inefficient lubrication. In addition to functioning in a very hot environment, the motor spends most of its time running at temperatures below 70°C. Poor or inefficient grease will cause the issue of an overheated hub motor issue, resulting in a cracked and locked bearing.
The temperature of the hub motor bearing system, which has a relatively stable limit value to manage, is typically 95 °C under normal conditions. The actual testing revealed that heat would transfer to the wheel hub motor when the bearing system is hot, and the bearing system suffers when the winding temperature increases.
The issue of casting flaws mostly affects hub motors with relatively big power and relatively long rotors. The rotor of the motor will heat up significantly during operation, and this heat will naturally transfer to the hub motor, heating it as a result.
Because the power of the motor load is almost constant, the voltage must be at least 10% greater than the rated value for the motor to operate without overloading the stator and rotor magnetic fields.
Alternately, the motor’s bearing may be damaged, increasing the strain on the motor and raising its temperature, heating the wheel motor.
Connecting Wires
You must pay close attention to the connection wires if your e-bike has a rear-hub motor. You should check the wires for indications of fraying if you’ve recently driven over rough terrain that might have jostled the hardware or if you’ve been hauling large luggage that could have added extra weight to the frame.
Damaged wiring can be potentially harmful in addition to damaging your bike’s performance. However, fraying is not limited to rear hub motors. It affects all motor types, including mid-drives and gear hubs.
Examine the electric motor, controller wire, and of course, the battery. A weak or problematic connection may result if one or more have come free. This should be your next action if you have already conducted a few on- and off-tests.
Unplug the device and check the connections for damage, dirt, or dust. This is a common problem with e-bike kits that were manually installed onto conventional bicycles. Try to scent the cables as you examine them.
Melting may result from overheating in your motor, and one quick method to tell if this is the case is to look for the powerful aroma of melted plastic or rubber.
Check for Free Play
You must have your chain and sprocket system examined by a specialist to see whether there is play. You can repair it if there is only a minor amount of slack. You may need to completely rebuild your rear hub motor or replace certain components if there is a lot of slack in your system.
Since internal gears are used in most electric bike hubs, replacement may not be an option. Therefore, if that is what you are dealing with, be sure to take it in for a cost estimate before starting any repairs.
Hub Motor Overhaul
Repairing it might be a smart alternative if you’re on a tight budget and only need to get your electric bike going or if you bought a secondhand hub motor. You must determine whether or not this makes sense in light of your circumstances in order to save money and the environment.
There are a ton of tools available if you choose to repair your electric bike hub motor yourself. Electric bike hubs frequently have forums with guides on how to overhaul them, videos, and other specific instructions from both makers and riders.
Ending Note
When something is wrong with your ride, you should first troubleshoot and test the electric bike motor. Even if there is no issue, regular motor tests can maintain your electric bike in top condition for years to come and help you avoid spending money on pricey repairs or buying a new one.
There is no harm in checking your motor to make sure it is in working order, but if a guarantee still covers your bike, opening the motor might void that warranty. Additionally, unskilled people may face risks when working with electrical wiring and connections. Please contact your manufacturer if you test your electric bike motor and discover issues that straightforward modifications cannot resolve.
Retrofitting an existing conventional bike with a hub motor allows riders who already possess one flexibility and is more cost-effective. Still, it can potentially have a detrimental effect on the bike’s performance and present safety risks.
The frame, chain, gears, and brakes of a standard bike are not made for motorized usage, and adding a conversion kit adds weight and stress to these components, which were not intended to withstand the greater loads and faster speeds of an eBike.
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My name is Matthew, staying in Seattle, Washington. Electric Vehicles (Electric Cars & Electric bikes) caught my attention for the last few years and my love for electric cars and bikes is everlasting. I spend many of my weekends traveling to various places all over various cities with my electric vehicle (e-bike and electric car). Here I am sharing my expertise, experience, and invaluable information about electric cars and electric bikes. Check out more.