What Are The Drawbacks Of A Mid Drive Motor?

The mid drive motor is a motor that is installed in the middle of the body, i.e. the pedal position. The motor is connected to the body and transmits power by connecting to the rear wheel through a chain. There are foot pedals installed on both sides of the motor, in case the motor has no power supply, you can still achieve riding through the foot pedals.

Disadvantages

1. Mid-mounted motors can be expensive compared to other motors.

There are very few electric cargo bikes with mid-drive motors under $2,000, especially from reputable brands, but there are plenty of affordable hub-drive e-bikes.

Hub motors are cheaper not because they are lower quality, but because they are less complex and therefore cheaper to manufacture. In terms of durability, hub motors are just as robust as mid drive motors.

While regular mid-drive cargo bikes have more advantages than regular hub-drive cargo bikes, they are also relatively more expensive. Of course there are some great hub-driven cargo bikes. But before you buy, you should always consider how the whole cargo bike fits together.

2. The drivetrain is more likely to wear out; the chain is more likely to be damaged.

Since the drive power needs to be transmitted to the rear wheel through the gear plate and chain, it will intensify the wear and tear of the gear plate and chain compared to a hub motor.

You can pedal at a higher wattage and it can last a long time, for example, your usually ride with 100W of power, while with a mid-motor drive, it allows you to ride steadily at 200W or higher power, but this time you have to consider the chain problem.

3. The cost of mid-drive motors is much higher than hub motors in terms of maintenance.

The structure of mid-drive motor is more complicated than hub motor. The whole structure requires clutch, drive shaft, drive chain, transmission, differential mechanism and other components to work together to output power to the rear wheels, in addition to the motor. These components not only add complexity, but also make maintenance more difficult. A cargo bike with mid-drive motor requires regular maintenance and is much more difficult to repair.

Although mid drive motors have some unavoidable disadvantages. However, its advantages far outweigh its disadvantages.

Advantages

1. The resistance of the mid-mounted motor is small and the rolling resistance is low.

Hub motor is generally brushless motor. It is a simple structure that affects the speed by controlling the current level, and is a typical magnetic induction drive principle. However, limited by the traditional structure, rotating friction, motor heat accumulation and other aspects, the motor energy efficiency is low. The conversion rate of electrical energy to kinetic energy is only between 70-80%. In addition, the traditional hub motor has always been "seepage phenomenon", that is, when the battery is constantly depleted, the electromagnetic resistance generated by the motor will gradually increase with the loss of power. That means it’s hard to keep riding without power, and the more you ride the harder you feel.

The mid drive motor is a power directly acting on the central shaft, and requires the clutch, drive shaft, differential and other components with the output of kinetic energy to act on the tooth plate, to assist the rider pedaling.

The motor is only responsible for the direct mechanical transmission, only the role of the vehicle pedaling force part. Its electrical energy - kinetic energy conversion rate is generally above 80%. The internal design of the clutch gear of the mid-motor can make the motor and the mid-motor gear completely detached under non-electricity. So when you normally ride your bike for sports and fitness, you can ride without any hindrance even if you are suddenly faced with the situation of running out of power.

2. The mid-mounted motor has more variable speed conditions and more torque, which also has better hill climbing performance.

Even if the torque sensing is added, the traditional wheel motor can only control the speed through the current, simply increase the speed to enhance the load and climbing torque, which will make the power consumption more, and more useless work, the overall efficiency is low.

The more technologically advanced mid-motor, which is a combination mechanism of internal variable speed gears, with multiple clutch gears inside the motor housing to form a variable speed gear, makes its output torque elevated and higher power for load and hill climbing. And its torque sensing is also more sensitive, sensing the change in pedaling effort of the crank, which will act directly on the mid-axis and accelerate more rapidly.

Since the overall basic shifting and transmission structure of the bike is not changed, riders can also work with the vehicle’s original mechanical rear derailleur mechanism, which can be used in concert with the mid-assist to achieve higher riding efficiency.

3. The mid-motor has a lower center of gravity distribution, which makes the whole vehicle’s center of gravity distribution reasonable and more suitable for sports bikes.

“Mid driver motor”, as the name implies, the motor is in the middle of the frame, so the vehicle’s center of gravity is still in the middle, which will not affect the balance of the vehicle under fast driving, and there is no need to arrange additional battery weight to counterweight.So most of the new models on the market today have the battery hidden in the down tube part of the frame.

On the other hand, the power effect is only on the center shaft, crank, disc, which normally simulates riding force, and does not change the rider’s habit of operating the mechanical shifting system, so different speed ratios can still be selected to match different road conditions and riding environments - thus making the mid-mounted motor more suitable for use on sport bikes.

And there is no additional burden on the braking system, no change in the under-wheel mass of the front and rear wheels, and no impact on the regular braking performance.

4. Fewer connection lines for mid-mounted motors, more streamlined accessories, and high integration.

All sensors are integrated in the mid-box, only one wire out, connected to the handlebar controller, even the battery connection is the concealed way of internal alignment plus contacts. This streamlined and integrated design makes the mid-motor bike easier to maintain, simpler in appearance and more convenient for the user.

After understanding in detail the pros and cons of the mid-motor, would you choose it? Tell us your choice in the comments below.