Mid-Drive Motors Explained

Mid-drive motors sit at the center of the bike frame, directly connected to the crank and pedals. Instead of driving the wheel itself, the motor turns the chain, using the bike’s gears to multiply power.

This setup gives riders a more natural pedaling feel and allows the motor to perform efficiently across different speeds and inclines.

Advantages

• Better Balance and Weight Distribution: Since the motor is positioned at the center of the bike, it offers better balance and weight distribution. This makes for a more natural ride and better handling, particularly on rough terrains.
• Efficiency: Mid-drive motors take advantage of the bike’s existing gears, allowing for better power efficiency. This is particularly beneficial on hilly or uneven terrains.
• Performance: Generally speaking, mid-drive motors provide superior torque and speed compared to hub motors of the same wattage. This makes them ideal for more demanding uses like mountain biking.
• Ease of Maintenance: The motor is separate from the wheel, making tire changes and maintenance easier.

Disadvantages

• Cost: Mid-drive systems are generally more expensive to purchase or retrofit on a bike.
• Complexity: The addition of a mid-drive motor often requires a more specialized frame and can add complexity to the bike’s overall build.
• Wear and Tear: Because the motor makes use of the bike’s chain and gears, it can cause faster wear and tear on these components. You can offset this by learning how to do your own chain maintenance and taking your eBike in for regular service.

Related: How to Prep Your eBike for Winter Riding

Hub-Drive Motors Explained

Hub-drive motors are mounted directly inside one of the bike’s wheels (usually the rear hub) and apply power straight to the wheel itself. This design isolates the motor from the bike’s drivetrain, making hub-drive systems simpler and often more affordable.

eBikes with these motors are ideal for riders who want a lower-maintenance, plug-and-play eBike experience.

Advantages

• Cost-Effective: Hub-drive motors are generally less expensive to purchase and install. They're often found on entry-level e-bikes, although high-end models frequently use them as well (especially when they’re combined with torque sensors, which cause the motor to deliver power in an intuitive way that feels closer to the experience of using a mid-drive motor).
• Simplicity: These motors are easier to install and are often less complicated than mid-drive motors, making them easier for DIY e-bike conversions.
• Independence from Drivetrain: Hub motors operate independently of the bike’s chain and gears, resulting in less wear and tear on these components. That doesn’t mean hub-drive electric bikes are maintenance-free, but it does mean you might spend a little less time oiling your chain!

Disadvantages

• Weight Distribution: The weight of the motor is concentrated at the wheel, which can make the bike feel less balanced and harder to handle, particularly on rough terrains. However, an eBike with the right frame geometry can offset this effect by compensating for the motor’s weight elsewhere in the design. The entire Surface 604 collection seamlessly integrates hub-drive motors in ways that feel natural.
• Efficiency: Hub motors are sometimes less efficient on hilly or uneven terrains because they’re further away from the pedals, which means more of the energy you produce can be lost before they kick in. High-quality hub-drive electric bikes sometimes use torque sensors to offset this problem by carefully measuring the amount of work you do while pedaling and using this to adjust the motor’s output.
• Maintenance: Replacing a tire can be more complicated on hub-drive eBikes, due to the integration of the motor in the wheel hub.

Comparison Chart: Mid-Drive vs. Hub-Drive Electric Bikes

When to Choose a Mid-Drive vs. Hub-Drive eBike

At the end of the day, mid-drive and hub-drive eBikes are both still popular because there are ideal applications for both types:

• Choose Mid-Drive If: You regularly navigate rugged terrains, and are willing to pay a little more or do a bit more maintenance for performance gains and better weight distribution.
• Choose Hub-Drive If: You ride mostly on flat terrains, value cost-efficient design, and are okay with potentially working a little harder on hill climbs.

Related: Why eBikes Are a Better Workout than You Might Think

That’s not to say all mid-drive eBikes are better than hub-drive versions. In fact, using torque sensors in a hub-drive eBike can improve the motor’s efficiency greatly and create an experience similar to that of riding a mid-drive model, and often at a lower cost! The important thing is to consider any bike you’re buying carefully and make sure it’s capable of taking you where you want to go.

Our team at Calgary eBikes is ready to help you find the ideal electric bike for your needs. Visit us today to explore some of the best mid-drive and hub-drive eBikes on the market, and browse the FAQ below for more information that can help you find the perfect ride.

Frequently Asked Questions about Mid-Drive vs. Hub-Drive eBikes

How Are Torque & Cadence Sensors Different?

A torque sensor measures the force you apply to the pedals and adjusts the motor’s output accordingly. This results in a more natural and intuitive cycling experience, which can help hub-drive eBikes feel more like mid-drive versions. Cadence sensors, on the other hand, simply measure how fast you’re pedaling and adjust the motor output based on that, regardless of how much force you’re applying.

Can you retrofit both kinds of motors to a non-electric bike?

Yes, you can technically retrofit both mid-drive and hub-drive motors, but the complexity and cost will differ based on the type of motor you choose. Typically, it’s easier to retrofit a hub-drive motor to a non-electric bike, although this can affect the weight distribution. We recommend purchasing an eBike designed to work with the kind of motor you want.

How Can Frame Geometry Offset Weight Distribution Issues in Hub-Drive eBikes?

The right frame geometry can help offset the weight distribution challenges of hub-drive eBikes. Essentially, this means that the design of the bike's frame can distribute weight in a way that balances the heavier hub motor, improving the bike's overall handling.

Do Hub-Drive Motors Only Go on the Rear Wheel?

Although hub-drive motors are usually placed on the rear wheel, they can also be placed on the front wheel. However, rear-wheel placement usually produces better traction and stability.

What Kind of Maintenance Is Required for Each Type of Motor?

Both types require general maintenance like checking for loose connections, ensuring that the battery is in good condition, and making sure the motor is free from debris. However, mid-drive motors may require more frequent drivetrain maintenance due to increased wear and tear on the chain and gears.

Can I Switch from One Type of Motor to Another?

Switching from one type of motor to another is possible but can be complex and expensive. It often involves not just replacing the motor but also making other modifications to the bike, like changing the frame or the wheel. This is why researching the kind of motor you want ahead of time is so important!