What is the best eBike motor for steep terrain, fast acceleration, and handling heavy loads? || Bafang Ultra M620

What is it that makes a great eBike motor? Is it power or torque or ease of use or smart sensors? I don’t think it’s any one of those factors; it is all of those things.

That is why our Storm and Mule bikes sport the Bafang Ultra M620. This incredible motor is often called the diesel engine of eBike motors. It exceeds in all these categories and more. In this post we will discuss why we chose to use this Bafang Motor and what sets it apart from lower end eBike motors on the market. 

Mid-drive Motor Basics:

EBikes can sport one of two types of motor, a hub drive or a mid-drive. A mid-drive motor, like the Bafang Ultra M620, has many benefits when compared to a hub drive motor:

  • The mid-drive is able to take advantage of a bike's gear system to provide more efficiency. Shifting gears allows you to stay at an rpm or “cadence” that is most efficient
  • The weight added by the motor is located in the middle of bike, having the motor low and centered feels more natural and easy to handle
  • Changing the tires is as easy as on a traditional bicycle where as, with a hub drive there are some additional steps when changing out the tire or a replacing a spoke
  • Removing the motor from the bike frame is simple. This makes servicing or replacing a mid-drive motor a simple process
  • Mid-drive motors will typically have better performance and torque when compared to an equivalently powered hub motor 

Basically mid-drive motors are a pretty incredible option when it comes to a high performance eBike. However, not all mid-drives are created equal! 

 What to look for in a mid drive motor:

There are some boxes that a mid-drive motor needs to check for it to truly deliver the incredible ride quality that is available on today’s cutting edge, high end, electric bikes. 


For one, on any top of the line motor from Bosch, to Yamaha, to Bafang,  to Specialized you will find that they all have a torque sensor. A torque sensor allows the motor to understand how much force you are putting down with each pedal stroke. The motor then responds appropriately. This keeps the ride smooth and prevents the jerky feeling of lower end motors. 

High end motors won’t just have a torque sensor they will also have sensors for the brakes, the gear shifter, cadence, and speed. This data allows the motor to integrate more naturally with the rider and also show relevant information on the screen. 

Water Resistance

Apart from sensors another feature that is important is the motors water resistance. For example our motors have a rating of IP X5, this means that our motor housing will resist sustained low-pressure water jet spray. At this rating a motor will have no problem if you run into rain or mud.

Max Torque

EBike motors can range in torque from a measly 30Nm up to 160 Nm. Higher torque will allow for faster acceleration, the ability to climb steep hills, along with the capability to pull heavy loads and use a trailer. To me a high torque bike also equates to “more smiles per mile” the ability to to accelerate fast and climb hills makes having a high torque motor a no brainer.

Metal Gearing

For a motor to be able to handle the force of all that torque it is important that it has a high end build quality. Many motors sport nylon gearing, this material is easily susceptible to breakage and even warping at high temperatures. Look for a motor that uses all metal gears. The metal gears will be able to handle higher torque. Also they will transfer power more efficiently through the system. 

Inside look at Bafang M620

As an example of a motor that fits the bill here is the spec sheet for the motor that we use, feel free to take a moment to nerd out:


Not all eBike motors are created equal. Even two motors that both tout a 1000W power output may still have many important differences that will affect the quality of ride and life of the motor. A motor is one of the most important aspects of an eBike so it is extremely important to look for a motor that fits the specifications you want. What do you value most in an eBike motor?