Generally speaking, electric bikes aren’t cheap. So, when buying an electric bike, you should take the time to make sure you choose the one that’s right for you. In which case, there are various considerations to make. One of these considerations should be what type of motor you want it to have.
The power of the motor is also a consideration when deciding on the right motor for your electric bike. But I talk about this in another article. So here, I will focus on the motor type.
Electric bike motors are either hub motors, which are positioned in the center of the front, or back wheel of the bike. Or mid drive motors, which are positioned in the middle of the bike, between the pedals. Whichever of these motors you have, will affect your electric bike’s price. As well as its performance and riding experience.
In this article, I will talk about the differences between these 2 motor types. This is to help you determine which one would be the right choice for you. Immediately below, is a table, briefly outlining the main benefits of these motors.
Now, throughout the rest of this article, I will talk further in depth about the advantages and disadvantages of these 2 types of motors.
Advantages of Hub Motors
The Cost
Hub motors are cheaper than mid drive motors. You may find 2 electric bikes, with similar specifications, except for the motor type. Here, you should expect the bike with the hub motor to be the cheaper one.
This is due to the design of hub motors being more standardized, compared with mid drive motors. Because hub motors are fitted to the wheel, they don’t interfere with the overall design of the bike. This often means their design does not have to be altered, to accommodate different shaped frames and bike sizes. This allows hub motors to be mass-produced, keeping their cost down.
Drivetrain Freedom
Hub motors are independent of the electric bike’s drivetrain. Whereas mid drive motors are integrated within the electric bike’s drivetrain.
If you’re not familiar with the term drivetrain, then it is the mechanism that gets the bike moving. It will include the crankshaft, pedals, gear mechanism and chain.
This drivetrain freedom you get from hub motors, allows for more versatile bike designs. Particularly with the frame. This is because, if the motor is within the drivetrain, the rest of the bike will need to be designed around it a lot more.
Furthermore, there will be less wear and tear on the drivetrain (particularly on the chain), if the motor is not incorporated within it. So you should expect the components within the drivetrain to last longer, if your electric bike has a hub motor.
Better for Conversion Kits
Due to this drivetrain freedom you get from hub motors. They lend themselves to being easy to incorporate as part of a conversion kit. These conversion kits are to upgrade an existing bike to an electric bike.
As hub motors are not embedded within the drivetrain. They are less technical to install (to a pre-existing bike), than mid drive motors. With hub motors, you only have the wires going to the controls and the battery.
Better for Throttles
Hub motors are often the preferred choice for electric bikes with a throttle. Again, this is due to the drivetrain freedom they provide.
If you’re out on a ride and your chain snaps, you can still use the throttle to engage the hub motor, to get you home. The hub motor allows this to happen, because it does not solely rely on the chain to activate it. Due to this drivetrain independence.
If the hub motor itself was to fail during a ride, you can still pedal your way home. With a hub motor, you always have a back up, giving you that extra assurance.
Having a throttle on your electric bike is beneficial, for the below scenarios.
- If you’re tired during a lengthy cycle and you want to avoid pedaling, for a rest on the way home.
- If you’re using an electric bike as part of injury rehabilitation, or if you’re not currently of a high fitness level. A throttle can be a reassuring extra to have.
Riding Feel
This is not necessarily an advantage, but more of a matter of preference. The wheel a hub motor is situated on will determine the general riding feel of the bike.
Rear hub motors give you a pushing sensation and front hub motors give you a pulling sensation.
Some people like the feel of how the bike pulls you on a front hub motor, as it can feel pretty natural. Front hub motors provide all wheel drive. This is due to the motor moving the front wheel, whilst your pedaling is moving the rear wheel. Certain riders appreciate this aspect. This is because it gives better traction on slippery and uneven surfaces. This makes it easier to ride over obstacles.
Other riders like the pushing feel you get with a rear hub motor. Here, you get a rocket propulsion sensation, which can be a lot of fun to ride.
Whether it’s a front or rear hub motor, some cyclists appreciate their legs feeling supported. This is due to the fact, the power is placed on the wheel.
Require Less Effort at Top End Speed
Hub motors require less pedaling effort than mid drive motors, to maintain a high speed once you’ve reached it.
This can be especially helpful if you’re using an electric bike for commuting. This is because it can assist with striking a suitable balance between getting to work quickly, whilst arriving without a sweat.
Disadvantages of Hub Motors
Uneven Weight Distribution
As already mentioned, hub motors are at either end of the bike. Either on the back wheel, or the front wheel. This contributes towards the weight not being evenly distributed throughout the bike. Unlike mid drive motors, which are centrally positioned on the bike. Meaning the bike may not be as well-balanced, with hub motors.
If the weight is not distributed throughout the bike, this makes it harder to cycle uphill. Having heavy components at the other end of the bike, can mitigate this issue though.
For example, if you have a rear hub motor, the battery may be nearer the front of the bike and/or there may be front suspension. These will help create a more even distribution of weight.
Not as Efficient Battery Use
Hub motors eat up more battery than mid drive motors. This is down to that they are required to move a whole wheel, rather than just a sprocket. So you will need a bigger battery, to get the same mileage you would get from a smaller battery, whilst having a mid drive motor. This can mean a heavier and more expensive battery. However, the lower cost of a Hub motor, compared to a mid drive one, will mitigate against any extra battery cost.
Difficult to Change Wheel/Tire
As Hub motors are located on the wheel, it makes it much harder to change the wheel or tire.
So if your electric bike has a hub motor, you especially want to avoid incurring a puncture. You can reduce the chance of this, by always having your tires pumped up to the recommended pressure. The tire wall will have this stated on it. This is more crucial, if you’re riding on off-road conditions. You can even make a point of using good quality/thicker tires, or any sort of tire liner.
Some higher end hub motor electric bikes have a through axle. This makes replacing a flat tire much easier. But you’re not going to find this on all hub motor electric bikes.
A tip to consider here, if you’re deciding between a rear or front hub motor, is that the rear tire is less likely to go flat. This is due to the fact that the front wheel can clear obstacles (like bigger bits of gravel), out of the way of the rear wheel. Knowing this could influence you to opt for an electric bike, with a rear hub motor.
You can always take your electric bike to a shop, if you need the wheels or tires replaced. But if you’re someone who changes their wheels or tires often, you may find having a hub motor to be a bit of a pain.
Reduced Handling on Front Hub Motors
Having a front hub motor can make turning and the general handling of the bike feel sluggish. This is due to the extra weight at the front of the bike. Having a suspension fork at the front of the bike, can exaggerate this further.
Advantages of Mid Drive Motors
More Natural Riding Feel
Because mid drive motors are integrated within the drivetrain, they operate closer to the source of the bike’s movement. Which, by the way, is your pedaling. This makes cycling feel a lot more natural, compared to riding electric bikes with hub motors.
These motors work in harmony with your pedaling and allow for the extra assist to be less noticeable. This makes you feel like you’ve got superpowered legs. Whereas hub motors can sometimes have more of a scooter feel.
Better Weight Distribution
Mid drive motors provide better weight distribution throughout the bike, compared to hub motors. This is due to their positioning at the center of the bike.
Better weight distribution throughout the bike makes it easier to climb hills. You will have less weight behind you pulling you back, or less weight in front of you to push up.
Having an electric bike with a mid drive motor, can give you more confidence to attach cargo to the back of your bike, compared to a rear hub motor. This is because the cargo will not disrupt the balance of your bike as much.
More Efficient Battery Consumption
Mid drive motors are much kinder on your battery consumption, compared with hub motors. This is because they are only moving a sprocket instead of a whole wheel, so there’s less effort required from the motor. Therefore, mid drive motors give you more range from your battery.
This can allow you to not need such a large battery to cover the distances you want, to allow for less weight on your bike. Or if you are sticking with a larger battery, you’ll get more out of it. For further information, about how to get more range from your battery during rides, I have another article, “How Can I Increase My Electric Bike Battery Range?”.
Better for Uphill and Off-Road
Mid drive motors are more efficient than hub motors. This makes it easier for you to climb hills and ride in off-road conditions with these motors.
As mid drive motors are part of the drivetrain, they are therefore leveraging it. As a result, your pedaling efforts become more effective. This gives you more torque, which provides an added boost. This makes mid drive motors superior compared to hub motors in demanding conditions, like riding up hills, or carrying cargo.
The integration within the drivetrain also means mid drive motors are working more in conjunction with the gears. Allowing the bike’s performance to be more efficient and responsive.
Generally Better Quality
Mid drive motors are often built to a better quality and with higher end engineering, compared with hub motors. This is because they need to withstand more stresses due to the torque of the rider’s pedaling. As a result, they tend to hold their value longer. Mid drive motors are simply a more modern design than hub motors.
Removing Wheels and Tires is Much Easier
Removing or replacing the wheels and tires is far less of a headache, if you have a mid drive motor. This stands to reason, since the mid drive motor is not attached to the wheels, like the hub motor.
This makes life easier if you ever have a flat tire, or a damaged wheel, or even if you wish to switch to a different tire type. For example, if you ever wish to switch from a thinner tire to a fat tire, for a spot of off-roading.
Disadvantages of Mid Drive Motors
High Cost
Mid drive motors have the bike designed around them, due to their position at the center of the bike. This means they are not as mass-produced as hub motors. Coupled with the fact they are built with more sophisticated engineering, means they are more expensive than hub motors. This increases the cost of the electric bike.
Difficult to Add to a Regular Bike
If you’re planning on converting your regular bike to an electric bike, this is hard to do with a mid drive motor. This is due to the motor being integrated within the drivetrain. Making it a complex task to add this motor to your bike yourself.
It can be equally tricky removing this type of motor. If you want to toggle between electric and regular bike (if you have a conversion kit), a hub motor is the easiest option for you here.
Wears Drivetrain Faster
As mid drive motors are part of the electric bike’s drivetrain, they cause it more wear and tear, compared to hub motors. This is due to the extra torque that mid drive motors provide, placing more stress on the drivetrain. This means having a mid drive motor can result in more maintenance.
In particular, the chain is more likely to snap on an electric bike with a mid drive motor. This is even more likely if you’re riding up steep hills, when the motor is applying even more torque and pressure.
Having higher quality components within the drivetrain can negate this tough. This can include a better quality chain, or even having a belt drive instead of a chain. Some electric bikes, with mid drive motors, can sometimes have an extra cog within the chain loop. This spreads the stress, to minimize the amount of stress on any single part of the chain.
Sometimes, mid drive motors have a gear sensor. This disengages the motor whilst you’re changing gear, to reduce wear and tear on the chain. General maintenance, like lubricating the chain, will help here as well. Muc-Off provides a chain lubricant
suitable for electric bikes.
Lower Positioning of the Motor can be Problematic
As mid drive motors are low down on the bike, there is risk of obstacles damaging them. This is even more likely whilst off-road cycling. With this in mind, you should be extra cautious when riding an electric bike with a mid drive motor.
Easier to Lose the Chain Whilst Riding
If you’re freewheeling and incur a vibration (say if you’ve ridden over an obstacle), this could cause the chain to fall off, if you have a mid drive motor. This is because a vibration can push the chain ring a little bit to the front. The advice here is to be careful of obstacles whilst freewheeling, with this type of motor.
Your Bike Can be More Likely to Slip from Excessive Force
Because mid drive motors leverage your pedaling power, that extra torque can make your bike more susceptible to slipping. You can mitigate this though, by using tires with good tread and cycling carefully. For example, by not cycling fast around bends. When comparing these 2 motor types, hub motors help your electric bike grip the surface you’re riding on better.
Conclusion
I hope this article gives you some idea of which of these 2 motor types would be most suitable for you. If you can clarify which type of motor you want, this will help narrow down your choice of electric bike, from the extensive choice out there.
You may be intending on riding an electric bike on hilly routes and/or for off-road riding. Here, the increased efficiency of the mid drive motor, which will benefit you in these scenarios, may make this motor type a clear cut choice for you.
If you’re planning on using an electric bike, solely for riding on flat, urban conditions. You may consider the extra efficiency of a mid drive motor not necessary and opt for an electric bike, with a hub motor, to save money.
Ultimately, you want the type of motor for your electric bike to be the most suitable one for your needs.