Why don't many electric cars use hub motors?

Models
1

Hey there, Why don’t many electric cars use hub motors? They seem like they’d be a good choice for custom upgrades too, but I haven’t seen many projects using them. Is there something about them that makes them not work as well?

2

Hub motors do offer some advantages, like simplified drivetrain design and potentially better traction control since power is delivered directly to the wheels. However, they also come with some drawbacks that might explain why they aren’t as prevalent in electric cars as you might expect.

  1. Unsuspended Mass: Hub motors add significant weight to the wheels, which increases unsprung mass. This can affect the ride quality and handling of the vehicle, as well as putting extra strain on suspension components.

  2. Thermal Management: Electric motors generate heat, and cooling them effectively can be challenging when they’re enclosed within a wheel hub. Overheating can lead to reduced performance and decreased motor lifespan.

  3. Complexity of Integration: Retrofitting or customizing a vehicle with hub motors can be more complex compared to traditional motor placement, especially in terms of integrating them with existing suspension and braking systems.

  4. Limited Space for Components:The space inside a wheel hub is limited, making it challenging to fit all necessary components such as motors, brakes, and suspension parts without compromising performance or safety.

  5. Repair and Maintenance: If a hub motor fails, it can be more difficult and expensive to repair or replace compared to a centrally located motor. This could potentially increase maintenance costs and downtime for the vehicle.

While hub motors might not be as common in electric cars as some may expect, they still have their niche applications, such as in electric bicycles and some small electric vehicles. As battery and motor technology continue to evolve, we may see improvements that address some of these limitations, making hub motors more viable for a wider range of electric vehicles in the future.

3

On smooth pavement, it’s not an issue, but imagine that heavy hub motor hitting a pothole at 50 mph. It’s not a kind way to treat an electric device. Another challenge is the one all electric vehicles face: batteries. Storing electricity is much harder than producing it.