Comparing Mid-Drive and Rear Electric Bike Conversion Kits

what is the best bike to e-bike conversion kit?
motorized bicycle, electric bike

Are you looking for a motorized bicycle, but don’t want to purchase one outright? Instead of diving in feet first, try dipping your toes in the water by exploring the array of e-bike kits available. 

E-bike kits allow you to transform your ordinary everyday bicycle into a powerful motorized e-bike. Before you buy any old e-bike kit out on the market, it is essential to:

  • Make sure the kit you buy is compatible with your existing bike
  • Be confident that you are mechanically minded enough to install and maintain your e-bike kit.

With this in mind, let’s explore our top four e-bike conversion kit options so you can weigh up the pros and cons of some of the best e-kits that are out on the market right now. 

Top 4 rated e-bike conversion kits for 2020

E-Bike KitBrandMotor Size/TypeFeaturesPrice
Bafang BBS02B (8fun)  48 volt, 
mid-drive motor
ChainringCranksLCD screen with button attachment Battery sold separately Check Price
Bafang BBS02B (8fun) 48 volt, 
mid-drive motor
ChainringBrake levers (or hydraulic sensors)Chain wheel and chainring plastic guardCranksA set of lock nutsEB-BUS waterproof cableLCD screen with button attachment Battery is optional extra (additional cost)Check Price
CSC MTB Rear E-Bike Conversion Kits 36 volt, 250-watt rear hub motor

Optional wheel rim dimensions: 20, 24, 26, 27.5, 29 inch and 700 C
Wheel rim Motor controllerHalf-twist throttleLCD screen Battery sold separately.Check Price
Unknown36 volt, 450-watt side mounted electric rare earth DC motor (DC)ChainFreewheel and freewheel adapterMotor controllerMounting plate and bolts Accelerator handle – twist throttle (with battery indicator and key stitch) Battery sold separatelyCheck Price

Mid-drive e-bike conversion kits explained

When you explore your options, it is best to start by understanding what a mid-drive electric conversion kit is. Mid-drive kits are designed to replace the standard chainring and cranks on your bike.

Mid-drive e-bike conversion kit motors use the rear cassette to improve climbing or speed (depending on which gear you are in). Mounting the mid-drive motor to your bike’s bottom bracket will propel and bring you and your bike forward. 

Mid-drive kits can be a bit tricky to install yourself, so you may need to work with your local bike shop. 

Bafang BBS02B (8fun) E-Bike Conversion Kits explained

There is a variety of different types of mid-drive conversion kits available on the market. Therefore, it is important to make an informed decision when purchasing your e-bike conversion kit. This will ensure you buy one that suits your needs and budget. 

The “Bafang” BBS02 e-bike conversion kits are manufactured in China by a well-established, reputable industry leader. When it comes to mid-drive e-bike kits, Bafang offers a range of high-quality mid-drive kits. Bafang e-kits include an instructional video to make the installation of your mid-drive e-kit a little easier. 

The tables below provide a summary of some of Bafang’s most popular e-bike kits. 

Bafang BBS02B (8fun) E-Bike Conversion Kit (750-watt)
Complete Kit48 volt, 750-watt mid-drive motor 
LCD screen with button attachment (thumb throttle)
Optional 48 volt battery 
Max Speed20 MPH
DisplayC965 LCD screen
Suitable forOn and off-road cycling. The 750-watt motor is excellent for hilly conditions.  

You’ll notice a significant price increase if you decide to purchase a Bafang BBS02B (8fun) e-bike conversion kit that includes the battery. Remember, if you buy your kit without a battery, you will still need to invest in this in the future in order to operate your electric bike. 

Bafang BBS02B (8fun) E-Bike Conversion Kit (500-watt)
Complete Kit48 volt, 500-watt mid-drive motor
Brake Levers (or hydraulic sensors) 
Chain wheel and chainring plastic guard
A set of lock nuts 
EB-BUS waterproof cable
LCD screen with button attachment (thumb throttle)
Speed sensor and magnet
68-73mm installing extra parts gaskets (gift)
A headlight and power extension cable (gift)
Optional 48 volt battery with charger
Max Speed20 MPH
DisplayEither C965 or DPC18 (both LCD screen)
Suitable forOn and off-road cycling

If you decide to purchase this kit, you will notice Bafang BBS02B and 8fun are used interchangeably. The company decided to rebrand the BBS02B to 8fun for the US market. Now you know why the term “Bafang” is occasionally on the LCD screen and “8fun” on the motor, vice versa. Go figure?

Essential mid-drive e-kit parts explained

e-bike, electric bike kit

Mid-Drive Motors Explained 

The advantage of Bafang’s mid-drive e-bike conversion kits is its versatility. Mid-drive kits can be installed on various bike types, including road, mountain bike, or cargo. 

When installing this kit’s various components, keep in mind that your bike’s bottom brackets must measure between 68mm and 73mm. 
Note: Due to physical constraints, you cannot install this kit on fat-tire bikes. 

One of the best features of the e-bike conversion kit is the 48 volt, 750-watt motor. This 750 wattage is the most powerful, legally compliant motor available for cyclists in the US. Even though the 750 and 500-watt motors can travel at a top speed of 20 MPH, the 750-watt motor provides more power when going uphill. Another feature of the Bafang motor is that it is relatively quiet, and this is handy when zipping around suburban streets. 

When it comes to installing this kit, it relatively easy for an experienced person. Remember that you must have a crank puller and spanner wrench to get started. If you are not feeling too confident about installing this kit on your own, contact your local bike shop for more assistance. 

LCD screen with button attachment

Your bike’s pedal assist and button attachment (thumb throttle) integrate well with the LCD screen. There are a variety of LCD screen models available on the market. Both the C965 and DPC18 LCD screens are a popular choice with cyclists because they are easy to use, and cyclists can navigate through the screen to check speed, trip distance, battery levels, and so much more. 

Another bonus of the DPC18 LCD screen is that it comes with an inbuilt USB port. This allows you to charge our phone while on the road. Note: The DPC18 LCD screen is not always an option that is available in e-kit packages.

After installing the LCD screen, it is pretty tough to remove. This means the screen will remain fixed on your bike, but the good news is that you can swivel the screen and angle it to view information better while riding your bike. 

Suitable E-Kit Batteries for the Bafang mid-drive e-kit

When purchasing your e-kit, keep in mind that some kits do not come with a standard battery. If you opt to buy a kit without a battery, it is best to work with a shop to select one that will mount easily to your frame and is suitable for your e-kit. 

When selecting your battery, look for an option that can be easily mounted to either the rear rack or downtube. And remember, a 48-volt battery should only power a 48-volt motor model. 

The Pros and Cons of the Bafang mid-drive e-kits

The Pros 

  • It operates at 20 MPH depending on wheel size and bike setup
  • You can use both pedal assist and throttle mode to allow for different styles of riding
  • It is more efficient than a hub motor because the mid-drive leverages the rear cassette for improved climbing or high-speed riding.
  • The weight of the mid-drive motor is relatively light, and because it is installed in the middle of the bike, it improves the frame’s balance and reduces unsprung weight
  • Mid-drive e-bikes are easier to service because wheels and tires are more accessible (more agile and responsive) 
  • Bafang is an established hardware manufacturer with a proven track record in producing quality e-components
  • Kit is compatible with a range of bottom bracket sizes (68mm to 73mm) 
  • LCD is backlit and lets you easily change settings like the number of pedal assist levels, speed readout, and wheel size.

The Cons 

  • The mid-drive motor is slightly louder than a majority of gearless e-kit motors
  • You will need to install this kit yourself. If you are not mechanically minded, you may need to work with your local bike shop
  • Cannot be installed on super wide 100mm fat-tire bikes
  • The mid-drive motor places extra stress on your bike chain 

To conclude

When it comes to versatility, power, and balance, this e-bike kit ticks all the boxes, but there is a high initial financial outlay. As long as you are comfortable installing it yourself, Bafang e-kits offer great value for money. They will help you fast-track your way towards a reliable electric bike experience.   

Rear-wheel e-bike conversion kits get their name because the motor is located on the rear wheel. There are two types of rear-wheel e-bike conversion kits available; they are the hub and side mounted motors. Rear hub e-kits are easier to install than mid-drive motors, but side mounted motors are considered more challenging. Either way, it pays to be mechanically minded, or in touch with your local bike shop for more assistance with troubleshooting. 

Rear-wheel e-bike conversion kits explained

When it comes to rear-wheel e-bike conversion kits, you are spoilt for choice. Rear-wheel kits are often referred to as the “fun option” because they sort of feel like you are riding a motorbike! 

A majority of hub and side-mounted e-bike components are manufactured in various factories across China. There are a variety of rear e-bike conversion kits on the market that vary in price and quality. If you are prepared to pay a little extra, it is recommended you purchase yourself a rear hub e-kit. Keep in mind that hub motors will make your bike pretty heavy.

CSCbike MTB Rear E-Bike Conversion Kit Explained 

CSC is rear hub e-bike conversion kits are manufactured in China. While Bafang is considered an industry leader, CSC is also well-established and has a reasonably reputable online presence. 

CSC MTB Rear E-Bike Conversion Kits Specifications
Complete Kit36 volt, 250-watt hub motor (also available in 48V)
Wheel Rim (double-wall aluminium alloy rim)
CSCbike e-bike controller (the brains of the bike)
Pedal-assist sensor
Half-bar twist throttle
LCD screen 
OptionalWire and tube
Not includedBattery – Compatibility is 36 volt, charger
Wheel Rim Size Optional dimensions: 20, 24, 26, 27.5, 29 inch and 700 C
Max Speed15 MPH 
DisplayKT LCD 3 screen
Suitable forOn and off-road cycling.

Key rear hub e-kit parts explained

Rear-wheel hub motor

The CSC e-kit motor is installed by replacing the rear wheel of your bike with a hub motor. The spin on this wheel works well since the weight of the rider is concentrated on the back wheel. To ensure this motor fits your bike, the CSC e-kit motors come in a variety of wheel size dimensions. The wheel’s wire and tube are optional extras. If you decide to purchase a 20” aluminium rim only, you will need a 20” x 1.75-2.25 tire.  

The pros and cons of the CSCbike MTB rear e-bike conversion kit

The pros 

  • The kit is compatible with a range of rear dropout bracket sizes (135mm to 142mm)
  • Chain and gears will not accumulate as much wear and tear as a mid-drive e-kit. This is because the hub motors do not use your existing drivetrain (chain, gears, pedals) to operate. 
  • These hubs are considered to be safer because of stronger dropouts in the rear. 
  • Cyclists can navigate through the screen to check speed, trip distance, battery levels, and so much more using the LCD screen.
  • Rear wheel hub motors are generally safer than the front wheel, and it feels like you are riding a motorbike. 
  • Hub motors provide good value for money. 

The cons 

  • You will need to install this kit yourself. If you are not mechanically minded, you may need to work with your local bike shop. Rear e-bike conversion kits are more difficult to install than front wheel hubs.                                   
  • The wheel can be a bit heavy. This means that the weight distribution on your bike will be slightly uneven. 
  • The battery and charger are sold separately

To conclude

The rear-wheel hub motor is excellent for flat, suburban streets. If you don’t need a lot of extra power to incline up hills, the rear hub e-kit is a cost-effective solution. However, if you need superior power, then you are best to invest in a mid-drive motor. 

When it comes to versatility and bike compatibility, the CSC MTB rear-wheel hub motor is perfect because it offers a wide variety of wheel rim sizes to fit many different existing non-motorized bikes out there.

Side Mounted Motor Design E-Bike Conversion Kit 

If you have a limited budget and are looking for the cheapest e-bike kit on the market, the side mounted motor design is probably your best and only option. However, be warned because it is a bit dicey, and the online reviews are mixed.  

Side Mounted Motor Design E-Bike Conversion Kit
Complete Kit36 volt, 450-watt electric rare earth DC motor (brushed motor)
Freewheel and freewheel adapter
Motor controller 
Mounting plate and bolts
Accelerator handle – twist throttle 
(with battery indicator and key stitch)
Not includedBattery 
LCD screen with button attachment – this is because this kit uses an accelerator handle (twist throttle)
Max Speed20 MPH 
Suitable forOn-road cycling

The pros and cons of the side mounted e-bike conversion kit

The Pros 

  • Can use a more cost-effective battery such as led acid. This bike does not need to operate using a Lithium battery.
  • The hub motor does not add extra stress on your chain or shifters 
  • If you have limited funds, this e-kit can be a great way to dip your toes in the electric bike scene. 

The Cons 

  • These types of e-kits are challenging to install in comparison to the rear hub e-kit 
  • It is safe to say that the manufacturer of this e-kit is based in China, but because they are “unknown,” their reputation and track record cannot be measured against
  • Customer feedback about the product parts from this supplier varies significantly. Often, if you can install the motor, it breaks quickly once in use
  • Sometimes, the parts will not fit your bike; be careful of the term “universal.” Universal parts do not necessarily fit all bikes out there  
  • The technology in this kit is basic. For example, you are using a twist throttle instead of the button (thumb throttle). This means you do not have an option to include the LCDs available in more modern kits. 

To conclude

The side mounted motor is the entry-level e-kit to buy on the market. It is suitable if you are on a restricted budget and are mechanically minded. However, it is worth noting that you get what you pay for with this e-kit. The product parts are really basic, and feedback has been mixed. It might be worth spending a bit more money and buying a slightly expensive and reputable e-kit. 

To close out

When it comes to e-bike kits, one size does not fit all. You need to do your homework and compare your options to ensure you get the e-kit that meets your needs.

Before you buy your e-kit, walk through this checklist:

  • Will the e-kit you select be able to be installed on your ordinary bike? 
  • Does the e-kit meet all of your specifications?
  • Is the type of e-kit you are selecting suitable for your riding experience?
  • Are mechanically minded enough to install your e-kit? 
  • Do you have support available if you need assistance with troubleshooting?
  • Does the e-kit you are looking at purchasing match your budget? 

Hopefully, this information has helped to answer some of the questions in your e-kit checklist. What else do you think is important to consider when buying an e-kit?