Have you ever thought, “Which motor should be on your next e-bike?”
If not, now is the time to think and make the right decision.
Different motors can be used in electric bikes, including mid-drive motors, direct-drive hub motors, geared hub motors, and friction motors.
Motors have a crucial role to play in electric bikes. They propel us forward and help us climb up hills effortlessly.
Different bikes have different motors, and it cannot be apparent to select the right bike. In general, hub motors are the most commonly used motors in electric bikes. They are of two types- brushed and brushless.
Here is a review guide that will better understand hub motors and answer all your motor mechanics questions.
What Is A Hub Motor, And How Does It Work?
Hub motors are found in the center of the bike near the hub wheels. In such motors, the shaft doesn’t perform the spinning action; instead, it acts as the rear axle. Here, the hub or the motor spins around the shaft, which remains fixed and performs the propelling action.
Hub motors have a decent diameter, enabling them to generate high-power torque output even at lower RPMs. These motors give rise to the regenerative braking mechanism, helping the rider move forward and backward with equal efficiency.
Energy gets saved to a large extent, as whenever the brakes are applied, the energy is absorbed in the form of electrical energy.
Types Of Hub Motors- Direct Drive Hub Motors and Geared Hub Motors
Direct Drive Hub Motors
Direct Drive Hub Motors are gearless motors that are designed for high-speed uses without getting overstressed. These motors have more significant hubs that leverage the high-power torque better.
These motors are located near the hub wheels and thus operate outside the bike’s chain drive. This helps them supply power at low RPMs. Also, these motors simultaneously convert braking energy into electrical energy, which helps to save energy.
- Very low maintenance
- Provide high-speed rides
- Generate electrical energy
- Minimal coast resistance
- Regenerative brakes system
- Causes less wear and tear
- Highly affordable
- Don’t climb up hills with ease.
- Require higher wattage
- Heavier in weight
- Bigger in size
- Require more magnetic material
- Generate low-speed torque
- Changing tires can be cumbersome, as the wires connected to the hub motor have to be disconnected.
Geared Hub Motors
Geared hub motors have a series of planetary gears. These gears are connected to the hub, which spins faster than the direct-driven hub motors. The actual size is smaller, but the gears make the motor look wider. There is no scope of regenerative brakes as these motors consist of a freewheel. However, they coast freely when not under power.
- High torque application
- Smaller in size
- High internal RPM
- Coast with less resistance
- Low speed
- Noisy design
- Get overstressed on high-powers.
- No regenerative brakes system
Advantages Of Hub Motors
There is a reason why hub motors have the edge over other motors in the market.
Given below are some advantages of hub motors:
All the components that comprise the hub motor are properly cased, which leaves the owner with nothing to maintain. Also, these motors are independent drive systems, which means they require no external care from time to time.
Geared hub motors might require some maintenance after some time as the reinforced nylon gears will wear-off after prolonged usage. But this problem doesn’t occur in gearless motors as there are no moving parts and no risks associated with them.
Since hub motors are placed at the center of the bike, they don’t cause any stress or wearability to other bike parts, such as chains or shifters.
These motors tend to add redundancy. In simple words, the bikes with hub motors have independent mechanisms for the pedal drive system and hub drive system, which means the rider can still get home even after losing one of them.
For instance, if the hub motor fails, the rider has the backup to pedal and come back. Likewise, if the chain gets broken and the rider can’t pedal anymore, he/she can rely on the motor’s power.
Helps in maintaining balance
If you have an electric bike with rear-mounted batteries, the hub motor can easily re-distribute the weight so that the center of gravity aligns with the bike center and the bike doesn’t get skewed to one side.
Hub motors come at a very low price as compared to other motors. Due to their increasing demand, they are getting manufactured at a massive scale.
Disadvantages Of Hub Motors
Everything has some downsides, so do hub motors.
Given below are some disadvantages of hub motors:
Only Single Gear Ratio Allowed
Single gear may be relevant if the bike is to be ridden only on flat terrains, but if the rider wishes to take the bike to uphills, then a single gear system may not help.
Heavier Than Mid-Drives
Hub motors are heavier than mid-drive motors that might interfere with the bike’s suspension, thereby impacting the bike’s overall performance.
Limited Options For Wheels
You may not always fit your favorite tires if you have an electric bike that uses a hub motor. Hub motors limit the choices of wheel components such as rims and cassettes.
Front vs. Rear Hub Motors
Although the owner can fit hub motors in either of the wheels, it does make a lot of difference.
When the motor is installed on the front wheel, it can help in effective weight distribution and balancing of the bike. Also, front wheels are more prone to road debris and bumps.
But rear hub motors tend to remain more robust than front ones and minimize the chances of causing damage to the forks. Rear hub motors provide better traction and grip on the road. Even at higher speeds, the problem of the gyroscopic effect gets eliminated.
Hub Motor Brands – Reviews
A review guide is incomplete without the information of brands that support that specific product.
When it comes to hub motors, there are various brands in the race of manufacturing.
Have a look at some of these brands:
Bafang or Suzhou Bafang is a China-based company dealing with the manufacture of motors for a long time. It has been one of the biggest manufacturers of electric bike hub motors for the past few years.
Rad Power and Juiced are two such companies that rely on Bafang hub motors for their electric bikes.
Mahle bike motion X35
This automotive manufacturer primarily uses geared hub motors instead of gearless ones. Still, they make sure that the motor blends into the system very subtly and delivers a smooth and effortless riding experience. The motors are made such that bikes in which they are fitted remain lightweight and handy to ride.
Despite having a motion-sensing system, Mahle bike motion never compromises with the smooth ride and easy assistance.
TranzX may not be a top-rated company, but you can rely on it for quality hub motors.
TranzX specializes in lightweight rear hub motors and front hub motors as well.
Dapu is a Japanese firm that has been good at manufacturing hub motors for the past few years. These motors can also be used in Pedego electric bikes.
ZEHUS is known for manufacturing “all in one” hub motors that can fit all the hub’s electrical system components.
Usually, these hub motors are gearless; thus, the rider might face a problem while climbing hills. In all other aspects, these hub motors cater to all needs of the bike and the rider.
Are Hub Motors Reliable?
Hub motors are the last thing you will have to replace or repair in your electric bike.
These motors require little or no maintenance. Thus, they can be easily relied on. Even the geared hub motors tend to have only a few moving parts and have a sturdy and stealthy structure, making them preferable over other motors.
How Long Do Hub Motors Last?
You will replace everything from brake pads to tires and from chains to batteries, but the hub motors will never be on your list.
Hub motors are very reliable and are designed to last longer than any other motor. The direct-drive hub motors are gearless and can last up to 10,000 miles or more.
While electric bikes have become many popular means of commuting and recreational riding, people still get puzzled while choosing the type of motor they should have.
Hub motors are more commonly used these days as they have many advantages, including low maintenance, low cost, quiet design, and better balancing. If you have an electric bike with a hub motor, then the last thing you will have to worry about replacing is the motor itself.