The major difference between a Hub Drive motor and a Mid Drive motor system is that a hub drive motor in an electric bike is installed in the middle of the back wheel in the hub. The motor gets current through the battery which is controlled by the controller and it starts to apply torque to the wheel, operating independently of your bike’s gears.
A mid-drive, however, instead of in the back or in the front wheel, is installed right in the middle of your electric bike, somewhere in between the pedals.
The principal characteristic of Mid Drive eBike is that human pedaling propels them. The motor is activated once the user pedals the wheels. Mid Drive eBike motor systems also include an electronic controller that stops the motor support when the rider is not pedaling or the bike reaches a set speed.
Most retailers supply more hub motors due to their affordability than mid-drive motors. They basically have only one gear. Although some of them are very efficient, they are not ideal for hilly areas. If you live in a city, these are just fine. Hub drive eBike motor system is best for adults who are not looking for the highest levels of performance, such as city riders.
If you want peak performance responsiveness that gives a similar feel to a pedal bike, mid-drive motors are the better choice. They also help you ride uphill faster. Further, mid-drive electric bikes are the better option when you want to avoid soaring gas prices and stay physically fit. However, before getting a mid-drive electric bike, you have to keep in mind the rules and regulations in your country regarding the e-bike’s speed limit.
Hub Drive: Front VS Rear Hub Motors
Since the motor is positioned inside the rear wheel on a rear-hub drive electric bike motor system, it is pretty close to the mechanism that makes a bicycle move forward. When you pedal and the chain is pushing against the cassette, a rear hub motor measures the force at the rear wheel. Once it calculates how much power you are putting in, it subsequently applies its own force directly to the rear wheel, propelling the wheel and in turn the whole bike forward.
Some hub motors are quite responsive: measuring power multiple times every pedal stroke. Whereas, the cheaper ones measure only a few times per stroke and are found on some hybrid or city-type e-Bikes.
Motors positioned in the front wheel are simpler than rear wheel hub motors, because they do not apply assistance to the drive wheel. Instead, a front hub motor senses when the rear wheel pushes it forward because it is directly attached to the front wheel. The motor applies assistance to the front wheel, meaning that you will get pulled along as you continue to pedal and apply your power to the rear wheel.
Some front hub motor systems have a sensor that can measure how much assistance to apply when it senses a certain amount of drive. Cheaper models may deliver a set amount of assistance regardless of how hard you pedal.
Pros of Hub Drive
Hub Drive Motors Are Versatile
From a manufacturing point of view, the hub drive motor can be attached to various electric bike frames with a few minor tweaks. Thus, electric bikes with a hub drive motor are considerably cheaper.
Further, hub-drive electric bikes do not need chains to operate: if you are tired of pedaling or your chain breaks, all you have to do is pull the throttle and you will be on your way to your destination as if you are on a scooter. However, if your chain breaks while on a Mid Drive eBike motor system due to added motor pressure, you will have to walk your way home because your mid-drive motor only works when you pedal.
Hub-drive electric bikes are good rehabilitators: they are best for when you are feeling down and depressed and want to take a refreshing bike ride without having to pedal. It is the better choice for those who are physically restricted from pedaling.
Hub Drive eBike motor system requires little maintenance as it is an entirely independent drive system that retains all its components inside the motor casing, leaving nothing for you to fix or maintain.
There are two types of hub motors: geared hub motors which have internal planetary gears that reduce the speed of a higher RPM motor, and gearless hub motors, which directly connect the lower RPM motor stator’s axle to the bike without any gears. Geared hub motors just have one setback: the gears can break off overtime, and the reinforced nylon gears might strip.
Gearless hub motors, however, have no moving parts aside from their bearings, so there is basically nothing to wear out.
However, like all modes of transportation, eBikes require maintenance and upkeep so they do not rust out or wear out their bearings.
Cons of Hub Drive
Hub drive motors put a considerable amount of weight on the rear or the front wheel, depending on where they are installed. A common criticism about hub-drive eBike systems is that they feel as if they are pushing (rear hub motors) or pulling you (front hubs) along.
Hub drive e-bikes are inferior to their counterparts (mid-drive motors) when it comes to off-road rides because a large amount of weight of the electric bike is concentrated on either the front or the rear wheel.
Further, if the hub motor wheel is not properly aligned, the ride can feel pretty unstable. Since the motor is away from the rider i.e., on the front or the rear wheel, the ride balance is also not ideal.
Might Deplete Battery Quickly
The throttle allows you to accelerate without pedaling at all. However, this mode rapidly depletes most batteries, so throttling at full speed is not advisable except in an emergency.
A lower speed but higher torque gear would be preferable for hill climbing, however, a single geared speed motor is not efficient when functioning at the lower RPM range under load and will deplete your battery immediately.
Hub motors are also heavier than their mid-drive counterparts and that weight directly falls on suspension, in turn reducing the effectiveness of the bike’s suspension and making the rider more vulnerable to road bumps.
Limits Wheel Choices
Hub motors might limit your choices when it comes to wheel components such as rims, tires and cassettes because you have to stick to the rim that is designed for your hub motor. With Hub Drive eBike systems you might not be able to fit your favorite tire in your bike. Further, the width of hub motors often precludes cassettes with more than 7 speeds.
Pros of Mid Drive
Natural Riding Experience
The mid-drive electric bike is a recent innovation in the world of electric bikes. It gives a rather natural bike riding experience: added thrill with the natural bike riding reward system as you do have to pedal in it. Further, there is no throttle in a mid-drive electric bike, the faster you pedal the faster it will go.
Unlike hub-drive electric bikes that are imbalanced to an extent, mid-drive electric bikes have superior balance and are the better option for offroad and downhill rides.
Changing Tires: More Convenient
Mid-drives can be more convenient when you have a flat tire: removing the rear wheel is just as simple on a mid-drive electric bike as it is on a normal bike because there is no hub motor installed in the front or the rear wheel. However, in a hub drive eBike system, you will need special tools and skill sets to remove the rear or the front wheel.
If you are planning to buy an e-bike for fitness purposes, then the mid-drive system is the best option for you in which the idea is to make your pedaling easier but not make you entirely dependent on the motor.
A mid-drive eBike can take advantage of your bike’s gears. Since electric motors operate have higher efficiency at higher RPMs, the mid-drive motors are tuned to operate efficiently at a natural pedaling cadence. So, the better you make use of your gears, the motor will operate in its comfort zone.
Given equal power and torque, a mid-drive motor will usually be better going up steep hills, assuming you shift to the appropriate gear. The ability to work together with your gears has other benefits, such as improved range, and it contributes to the more natural ride experience of most mid-drive.
Since mid-drive eBike motor systems operate at higher efficient RPMs when partnered with your bike’s gears, they have better range than their counterparts: hub-drive eBike motor systems.
In theory, a 500Wh battery on a hub drive eBike is only good for about 30 miles, whereas the same size battery can give 40-50 miles for a similar effort on a mid-drive. Further, the lower the pedal assist in a mid-drive, the higher range it will give since a higher pedal assist quickly depletes the battery.
Cons of Mid Drive
Might Leave You Stranded
The mid-drive motor system is not as versatile as the hub-drive system, so the electric bike’s frame has to be designed around it. Thus, the mid-drive electric bikes also come with a higher price tag.
The mid-drive motor system can put added stress on the chain: when you pedal, you stand on the pedals, putting pressure on the chain. With the mid-drive motor system, there is an added pressure in the form of torque on the chain due to which the chain can sometimes break. Thus, the mid-drive motor system might put your chain at risk when there is a steep climb. Hence, while using a mid-drive motor, the components might need to be replaced frequently.
Electric mountain bikes have different levels of pedal assist. The highest level of assist makes your pedaling effortless but drains the battery quickly.
Harder to Shift Gears
In mid-drive eBike motor systems, you cannot shift gears unless the bike is moving (except for rare bicycles with internally geared rear hubs). Thus, if you were in a higher gear descending downhill but are forced to stop following a red light, you will have to downshift the gears before coming to a halt. Else, you will be stuck in top gear when you try to accelerate after stopping which will put considerable strain on your legs.
Do not shift gears while under motor power because it will rip your chain in two because when there is too much torque in an electric motor, the extra stress can easily break the chain when it is between cogs.
HIgh-end mid-drive e-bikes models have gear shift interrupters that briefly cut the throttle when you shift gears. But many e-bikes lack this feature, and hence it is your responsibility to remember to relax the throttle when changing gears.
The bottom line
Hub Drive VS Mid Drive eBike motor systems: which is the best option for you? It entirely depends on your reasons for getting an electric bike.
The main advantages of the Hub Drive eBike system include: low cost maintenance, operates independent of pedals and they can be attached to various electric bike frames with a few minor tweaks. On the other hand, the Mid Drive eBike motor system has a longer range, keeps your fitness on track and its tires are as easy to replace as in a normal bike.
If you live in a city and are looking to get from point A to point B in the quickest and convenient way possible, then the Hub Drive eBike motor system is the best mode for your transportation. But if you are a cycling enthusiast and want to go on off road adventures occasionally, then the more natural and newer Mid Drive Ebike motor system will suit your needs best.