Deep Dive - Hub Motor or MidDrive?

The electric bike industry has matured greatly over the last dozen years. With sales now more than $20 Billion annually, and with well over 130 million e-bikes in all configurations and styles, they can be found around the globe being used daily. It has become nearly impossible now to go out and NOT see an electric bike cruising down the road, walk way or bike trail.

Though electric bikes were actually first developed in the 1890's, it has only been in the past few years that technology, manufacturing prowess, and demand has risen to allow the industry to scale to the levels that they have. Reasons for this growth are numerous and varied. Interest in EV tech; the Chinese manufacturing effect; government mandates, and of course - the pandemic. These are only a few reasons. Suffice it to say, e-bikes are the most popular and affordable form of EV out there. There are many riders that have kicked the car habit to the curb and use an e-bike, e-trike or recumbent as their primary form of transportation.

Let's face it, the market is glutted with e-bikes in all shapes, styles and price ranges. For the North American market, many, if not most, are mass produced in Asian countries with most of those targeting low pricing as a top priority. You get what you pay for fits well in this circumstance. In our dealing with electric bikes in our e-bike shop, we were confronted with all sorts of styles of e-bikes and all sorts of ways that drive systems were incorporated. The wide variety of styles was based on the equally wide number of ways that riders wanted to use their wheeled transportation.

The choice of drive system should be the top priority for several reasons. The drive system is fundamentally responsible for the bike's performance, affecting factors such as speed, range, and overall user experience. An efficient drive system not only enhances the power delivery and responsiveness of the bike but also influences how it handles various terrains and weather conditions. Additionally, different drive systems come with varying degrees of maintenance, complexity, and cost, which can impact long-term ownership satisfaction. Thus, before making any decisions regarding the frame, battery, or aesthetics, understanding the characteristics and benefits of the available drive systems is essential to ensure that the final e-bike aligns with the rider's specific needs and preferences.

Without targeting a certain type of rider or experience level, let's look at the heart of an e-bike's drive system - the motor. Our focus will be on the conversion of a bicycle, trike, or recumbent style, and what type of motor might be best for your situation. Perhaps you have already experienced e-bikes and are ready for something new and exciting. Perhaps you're a serial tinkerer and like the idea of a new challenge. Maybe you just want more performance, or have found a new purpose for riding. The choices are wide and varied. Welcome to the exciting world of e-bikes.

A Preface: When we state the term "e-bike" or "electric bike", these terms can be used to describe a wide variety of styles including, but not limited to the following:

• Commuter

• Hybrid Bike

• Road Bike

• Gravel Bike

• Touring Bike

• Folding Bike

• Cruiser Bike

• Mountain Bike

• Tandem Bike

• Recumbent Bike or Trike

• BMX Bike

• Upright Trike

• Fat Bike

• Cargo Bike

When converting a bicycle, trike, or recumbent to electric, the choice between hub motors and mid-drive motors is pivotal. Hub motors, mounted in the wheel, (front, rear, or both) offer advantages such as simplicity, lower maintenance, and (possibly) easier installation. They can excel in relatively straightforward setup and benefit from reduced mechanical complexity, making them ideal for casual riders. However, they generally have limitations in hill-climbing ability, weight distribution, and efficiency, especially in varied terrains.

Hub motors come in a large variety of brands, sizes and styles. Two of the most common types are the direct drive and the geared hub motor. A direct drive motor consists of basically two components - the outer hub and the internal rotor. As with any DC motor, internal sensors trigger a pulse of electricity to fire up an interaction between the coils in the rotor and the magnets on the outside hub. The advantage to this design is pure simplicity. The disadvantage - weight.

The geared hub motor normally contains a smaller motor, but also uses an internal planetary gearing set that allows the motor to run at a higher RPM, effectively reaching its sweet spot in power conversion. This increases efficiency and reduces weight. The disadvantage - more parts.

The geared hub motor has become a mainstream choice for e-bike manufacturers due to its cost effectiveness and reliability. The direct drive motor is popular with builders looking for power choices, as many motors can be seriously overvolted. This all goes back to what the user wants and needs out of the motor.

Now, let's look at a design that has been in strong development only over the last dozen years. Mid drive motors, which are positioned at the bike's bottom bracket, deliver superior torque and efficiency, particularly on inclines or rough surfaces. They utilize the bike's gears, allowing for optimized pedaling and energy use. Depending on manufacturer, a mid drive can offer cadence sensing, torque sensing and/or a throttle.

A cadence sensor is built into the heart of nearly every ebike out their today (Exception - ProdecoTech). When a rider begins pedaling, the sensor is triggered and sends pulses to the controller. Based on the level of assist that is chosen, power is then sent to the motor, again in timed pulses, which translates to rotory motion. Basically, a cadence sensor is on or off but is effective for most purposes.

A torque sensor on an electric bike is a key component that measures the amount of force applied to the pedals by the rider. This sensor plays a crucial role in enhancing the riding experience by providing real-time feedback to the bike's electric motor, allowing it to adjust the level of assistance based on the rider's input. By detecting how hard a cyclist is pedaling, the torque sensor ensures that the motor delivers the right amount of power, creating a seamless and natural riding feel. This feature not only makes acceleration smoother but also improves overall control and efficiency during rides. With a torque sensor, riders can enjoy a more intuitive interaction with their e-bike, making climbs easier and long distances more manageable, ultimately leading to a more enjoyable cycling experience.

A throttle is more a matter of convenience, but does have several advantages. Let's say you're out on a long ride, and a knee flares up. Just hit the throttle and get back to the truck. Worn out from a long uphill ride and just want to get home? Hit the throttle. Live in an area where throttles are not allowed due to classification restrictions, or just want a cleaner look to your bike? Just remove the throttle and cap the connector. The choice is yours.

While mid drive systems can (possibly) be more complex to install and may require more maintenance due to chain wear, their overall performance, adaptability to diverse riding conditions, and ability to maintain a balanced weight distribution make them the preferred choice for serious cyclists seeking enhanced performance and versatility.

Now, a look at real world riding examples. Let's say you have a good quality mountain bike and are looking for an affordable way to add power. A mid drive is the way to go, as it centers the weight of the drive system and eliminates unsprung weight that is so important for proper handling off road.

What if you get a flat tire? With a hub motor, you will need to bring extra wrenches to unbolt the wheel along with the electric power connector. Doing this the first time can be a bit daunting. Some bike shops still shy away from it to this day. But like anything, there is a process to it, and with the right tools it's doable. A mid drive system eliminates this hassle as the wheels are like a conventional bike. Pop them out just like you would with an unpowered vehicle.

These are just a couple fo examples. Both motor designs have advantages and disadvantages, when one looks at overall cost, wear on components and performance. To find the right motor for your situation takes research. The web site where you are reading this offers a mid drive solution that covers all the bases for affordability, reliability and performance. Our 14+ years of experience in e-bikes of all types, has gotten us to the point that this is all we sell. You are the only one that will know what motor is best for you. We urge you to take your time and do your homework. A quality drive system can make a world of difference in your e-bike experience.

Please reach out to us with questions or comments.