Electric bicycles are rapidly becoming one of the most popular modes of two-wheeled electric mobility for commuting and leisure riding. Hub and mid-drive motors are the two most prevalent electric motor designs in today’s electric bicycles. Which one is ideal for your needs? Continue reading to find out more.
The most popular type of electric bicycle motor is the hub motor, which places the electric motor in the center of the bicycle wheel.
Mid-drive motors, which house the motor closer to the center of the bicycle and transfer the motor’s power to the rear wheel through the chain drive, have grown much more prevalent in the recent 2-3 years, threatening the hub motor’s reign as the king of the e-bike motors.
Both have distinct advantages and disadvantages, so selecting the proper motor for you will be determined mainly by your requirements and which benefits appear to be more beneficial to your demands.
Advantages of electric bicycle hub motors
One of the most significant benefits of hub motors is that they require little to no maintenance. They are a completely self-contained drive system that keeps all its components inside the motor casing, leaving nothing for you to tinker with or maintain.
Because the system is enclosed, there is less to fail. Geared hub motors contain internal planetary gears to reduce the speed of a higher RPM motor. Gearless hub motors, which have no gearing and directly link the lower RPM motor stator’s axle to the bike, are the two types of hub motors. Geared hub motors typically have just one point of failure: the gears. A tooth can fall off with time, and the strengthened nylon gears will inevitably strip.
On the other hand, gearless hub motors have no moving components other than their bearings. Therefore there is nothing to wear out. They can survive indefinitely if they don’t corrode or wear their bearings.
Compared to mid-drive motors, hub motors can minimize other bike maintenance responsibilities. Hub motors provide no extra stress to your chain or shifters. They do not make any of those elements wear out faster because they are not connected to the primary pedal drive system. If anything, your chain will likely live longer than on a non-electric bike because the hub motor will perform more work, enabling your chain to rest idle more frequently.
Hub motors enable redundancy as an independent driving system. Because the hub motor and pedal drive mechanism are wholly separate, you may lose one and still travel home on the other. When your chain snaps when you’re tearing up the trail? Throw the chain in your backpack and bike home on only electricity. What if the hub motor fails? Return the pedal. In either case, you’re covered. This is especially important if you’re far from home, especially for senior riders or those who use e-biking for rehabilitation.
Depending on the conditions, a hub motor’s weight can favorably and adversely affect a bike’s balance. In some instances, weighting a motor further forward or backward in one of the wheels might be beneficial. This is especially true for e-bikes with batteries positioned in the back. A front hub motor can shift the weight such that the center of gravity remains in the middle of the bike in such instances.
Finally, hub motors are far less expensive than mid-drives. Depending on the facility, hub motor motorcycles are mass-produced in the hundreds of thousands, if not millions, of units. In some situations, the same designs have been used for over a decade. This signifies that the prices are meager.
Disadvantages of electric bicycle hub motors
Of course, hub motors are not without flaws.
Most notably, practically all hub motors support just a single gear ratio. While this is ordinarily sufficient for flat-land cruising, a lower speed but greater torque gear would be ideal for hill climbing. Using a single-speed motor is inefficient when operating at lower RPMs under load.
Hub motors are often heavier than mid-drive motors, representing unsprung weight on suspension bicycles. This can diminish suspension efficiency and convey more bumps to the rider.
Regarding wheel components like rims, tires, and cassettes, hub motors might be more restrictive. Because you’re confined to the rim that came with the hub motor, you might not be able to fit your preferred tire. The width of hub motors typically prevents cassettes with more than seven gears from being used.
Tire changes are considerably more difficult with hub motors since you must frequently disconnect the motor wire or pull a heavy tire around while still tied to the bike. However, You can replace some pretty unique bicycle inner tubes without having to remove the bike wheel – perfect for hub motors.
Front hub motors vs. rear hub motors
Hub motors may be mounted on either wheel, and the distinction produces a few additional distinct advantages and disadvantages.
Because more weight is often concentrated on the back tire, front hub motors can assist in better weight distribution.
Front wheels also get fewer flats than rear wheels because they kick up road debris and prepare it for the rear. A front hub motor frees up the back wheel for easy tube and tire replacements.
However, because less weight on the front tire of a bicycle equals less traction, more powerful front hub motors can occasionally produce burnouts when pegging the throttle. Front forks aren’t as strong as rear dropouts, so a powerful front hub motor can harm the fork over time. However, this can be alleviated by fitting a torque arm. Strong hub motors rated at 750 W or above are usually housed in the back of a bike.
Rear hub motors provide higher traction and stronger frame installation.
They also do not produce an unusual gyroscopic effect while steering at high speeds.
Perhaps my favorite aspect about rear hub motors is that they provide more of a motorcycle pushing sensation rather than the pulling sensation of a front motor.
The differences between a front and rear hub motor are nearly indistinguishable after establishing a constant pace and going on a straight path.
Advantages of mid-motor electric bicycles
Mid-drive motors were created to address many problems with hub motors.
The gear ratio is the most significant benefit of mid-motors versus hub motors. They let the rider power the back wheel with the same chain and gear set that powers the pedals, allowing a low gear to be picked for powering up steep slopes or accelerating from a stop with huge torque. A mid-drive motor in low gear can climb steep hills than a hub motor of comparable power. It can climb hills for a more extended period than a hub motor, which can overheat on lengthy steep hill climbs.
A mid-drive motor is often smaller and lighter than a comparable power hub motor. Mid-drive, smaller and lighter motors are frequently more discrete since they may be integrated directly into the bicycle frame. Many people are unaware that a mid-motor bike is an electric bike just by looking at it.
Because there is no hefty hub motor to contend with, changing a tire on a mid-drive motor e-bike is significantly easier. You swap it out like a regular pedal bike. Furthermore, because you can use standard bicycle wheels, you can use whichever wheels, tires, and cassettes you like.
Finally, mid-drive motors enable genuine torque sensors for pedal-assist systems, which control motor power based on how hard you push on the pedals as measured at the crank. Hub motors rely on cadence sensors for pedal assist, which only adjust motor speed based on pedal speed. They might result in jerky or uncomfortable motor timing, particularly while climbing hills or maneuvering the bicycle around obstacles.
Disadvantages of electric bicycles with mid-motors
Of course, there’s another side to this coin. Mid-drive motors may be harsh on your drive system, possibly their most serious drawback.
A healthy individual can maintain 100 W of power for an extended period, and 250 W of power during a strong sprint is regular. Mid-drive motors, on the other hand, may consistently generate 250-750 W of power. That’s like having a professional cyclist pound on your pedals all day. A cheap bicycle chain has no chance.
Because broken chains are probably the most common maintenance issue on mid-drive e-bikes, retail mid-drive e-bikes frequently come with improved bicycle chains. Because both the motor and the pedals rely on the chain to turn the wheel, riding a mid-motor e-bike with a snapped chain is solely a downhill experience.
One method to avoid the chain issue entirely is to buy a mid-drive e-bike with belt drive, but keep the extra cost in mind.
There are additional sites of failure in a mid-drive motor due to the increased number of moving components. If the motor fails and is integrated directly into the bicycle’s frame, replacing it may be more expensive than just switching out a hub motor.
In reality, mid-drive motors are more costly than the tried and reliable, mass-produced hub motors seen on many e-bikes.
Mid-drives have several advantages over a traditional hub motor technology, but they have difficulties. Hub motors have been around for a reason – they function.
Mid-drive vehicles have reduced weight and better gear utilization, making them more suitable for off-road and traversing mountainous terrain.
Hub-motors, on the other hand, are reasonably robust and low maintenance, making them ideal for commuters and people looking for a basic, reliable e-bike with minimal maintenance.
On the other hand, off-roaders prefer the power and dependability of hub motors. At the same time, commuters favor lightweight, stealthy, and discreet mid-drive motors. It all comes down to which characteristics suit you the best.
After all, the finest e-bike motor is the one you have. So go out there and ride!
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