As electric bikes are gaining popularity with time, many riders are shifting toward this two-wheeled electrical transportation for commuting and exploring and it's common to get curious about the core function of e-bikes motors.
There are two main e-bike motors, the hub drive and the mid-drive motor. Both have unique mechanisms, but they serve one purpose, powering up the e-bikes. So if you're having trouble deciding which type of e-bike motor you require for your rides or simply want to learn more about them here's great explanation.
Mid Drive motors are the most widespread and cheaper type of electric motor found in e-bikes and it's usually located in the center of the rear wheel but it can also be found on the front or both wheels. In general, hub drive motors have a cadence sensor that measures how quickly the cyclist is pedaling and enables pedal assistance based on the speed. This mechanism is more similar to a pedal activated motor.
Now let's look at the advantages. First, hub motors are typically easier to maintain and might even need no maintenance due to their drive system being integrated into a chassis. They can easily fit into a wide range of bike frames. As the hub drives have been in the bike industry for a long time, there are many options to choose from. Like low and high-power modes or maybe different wheel sizes and many more, plus it's not connected to the chain drive or shifters so hub motors won't stress your bike parts like mid drives.
Moreover, the hub drive motor operates by directly putting cadence to the wheels within an enclosed system. And there are two types of hub motors, a geared hub motor and a gearless one. The gear hub drive motors have internally placed gears that can manage the speed formation of a higher rpm motor, whereas gearless hub drive motors are also known as direct drive due to their wheels axle passing through the center of the motor is the axle of the motor itself.
Besides, as the e-bike's pedal system and motors are completely independent, this puts a plus point on its redundancy because if somehow the motor breaks, you can pedal and get home or vice versa This would be impossible on mid-drive motors due to the direct connection with chain drive. If the chain snaps, you'll have no option but to carry the bike back.
Lastly, coming down to weight management of e-bikes with hub motors, its effects vary with different circumstances. For example, if the hub motor is situated on the front wheel and the battery pack is on the back. Iin such a case they will balance out the center of gravity of the back.
So, let's look into the disadvantages now. Because nothing is perfect, not even the
hub drives. The first disadvantage is the limitation of compatibility. With gears and hub drives, e-bikes perform better at higher rpm, which is where the hub drive lacks compared to the mid-drive. Climbing steep terrains can get exhausting if you're riding with a hub motor integrated e-bike. Further, hub drives are heavier and sometimes not fitted in a bounce proportion on the bike, making the bike's weight distribution uneven. Plus, it limits the flexibility of choosing the preferred wheel components, like rims tires and cassettes because you'll be stuck with the wheel that comes with the hub motor.
Another thing to mention is that the geared hub motors have the possibility of geared tooth breaking off because of continuous use of high power, so that's why a gearless hub drive is a better choice. It won't be an issue until the rust forms or the bearing wears down.
You can say that gearless hub drive motors pretty much last eternally. The hub drive motors have been there for decades and are still being used today because they serve their purposes. With its power and capabilities, it's simple and requires minimum maintenance so it's a good choice for the commuters or those not requiring a considerable amount of power for riding.
Now that we've discussed the basics of hub-drive motors, let's move on to the mid-drive. This type of e-bike motor drives through the pedal cranks. More precisely, they are located at the center of the bicycle. With control over the chain drive, it transfers power from the chain drive to the rear wheel, just like the pedal, giving riding a more natural feel. It started gaining popularity over the past couple of years and has proven to be much more potent than hub drive motors. And mid-drive engines utilize a torque sensor to assist the rider which detects the rider's pedaling force rather than the speed, and then assists the rider while contributing force while pedaling.
Let's look into the advantages first. The first and foremost advantage to focus on is the gear ratio. Mid-drive motors work in tune with the chain drive, taking advantage of the bike's gears. It makes off-road riding smoother, allowing more control and power when climbing steep hills.
Furthermore, mid-drives are lighter and smaller than hub drives of similar power. Plus these motors run at a much more efficient rpm, ensuring a higher range. So a 500 watt hour battery can power a mid-drive motor for approximately 40 to 50 miles while a hub drive can run for about 30 miles on a similar setting. On top of that, mid-drive motors look sleek and stealthier on a bike not just due to their size but also for its integration point. It's fitted right at the middle of the bike making the bike feel evenly weighted. And most people won't notice the mid-drive motor's presence at first glance. But the hub motor, mostly the single wheeled, feels like an extra pull or push because of its location on the wheels.
Finally, changing the tires of amid-drive e-bike feels like changing a traditional one because of minimum complications on the wheels. But that isa big downside for the hub drive motors. You need a set of different tools and go through a complicated process just to change a tire. Moreover, mid-drive motors won't limit you in choosing the tire or wheels you desire as long as they fit the frame.
Moving on to the disadvantages, you might face with a mid-drive. After learning about its drive mechanism, we all can guess that it put the most pressure on the chain, drive leaving a huge chance of snapping the chain any time. And a solution to this issue is putting some more dollars on the bike and getting a mid-drive bike with a belt drive system. Besides, it's better to remember never to shift gears when driving on motor power. It will instantly snap the chain due to not being able to handle so much power.
Talking about the power, a normal human being, in healthy condition, can pedal with 100 watts of power for a long time which can reach nearly 250 watts maximum if the rider is sprinting hard for a sudden burst. At the same time, a mid-drive output range is about 250 to 750 watts continuously, which of course can be brutal to the bike, making the snapped chain a leading issue for many mid-drive riders.
As there are a lot of engaging parts of mid -drive motors, there are a lot more chances of failure compared to hub drive motors. Plus maintenance or replacement can get a bit too expensive mostly for the frame integrated mid-drive motors.
Well, everything is a mixture of negatives and positives and them same goes for these e-bike motors. One might opt for a mid-drive e-bikes for off-roading because they are lightweight but the hub drives are great for commuting due to their simplicity. But that choice varies too. There is no mainstream usage of any. Whichever suits your riding style and comfort is best for you.