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Best electric bike conversion kits: Give your current bike a power boost

Included in this guide:

Swytch Electric Bike Conversion Kit
(Image credit: Swytch)

If you don't want to buy an e-bike outright, the best electric bike conversion kits allow you to transform the bike you already have into something that gives you the boost you're after.

Electric bikes have come into the global conversation in a big way, and there are lots of benefits to having one: they make the world more accessible without jumping in a car, they still provide a great workout, they make difficult hills a thing of the past, they're cheaper to run, easier to park, and allow you to cycle from a to b at a higher pace for less effort.  Whether you're looking for the best electric bike for commuting or want to hit the trails after work with the best electric gravel bike, the right e-bike lets you tackle longer days, steeper hills and carry heavier loads, with faster speeds or lower levels of effort. It's no fluke that they are suddenly everywhere and everyone wants one.

The only thing that might be stopping you is the price of one. A way around that is to convert a bike you've already got sitting around. Waste not, want not, right? You've already got a bike you love, so why spend money on a brand new bike when, with the right knowledge and the right kit, you could take that old bike and add electric assist for less money and less hassle. 

Continue reading to see our suggestions for the best electric bike conversion kits, or jump down to the bottom and see some of the things to think about as you shop. Alternatively, if you're looking for a bargain, head to our Cyber Monday bike deals where you'll find over 280 deals on bikes, components and accessories, or check out our roundup of Cyber Monday electric bikes

Best electric bike conversion kits

BBS02B Mid-drive motor kit

(Image credit: Bafang USA)

Bafang Mid-Drive Motor Kit and Battery

A mid-drive all-inclusive kit from one of the best-known brands in the industry

Specifications
Wattage: 500
Battery included: Yes
Motor position: Crank
Reasons to buy
+US support+Lots of options
Reasons to avoid
- Needs better instructions 

Bafang is one of the largest and most well-known electric bike motor companies in the world. It's been around since 2003 and in 2014 Bafang established a US arm to better support the US market. There are many well-known electric bike companies sourcing its components, so if you want to get in the game and source your own electric bike components, you won't go wrong with Bafang.

This particular option covers everything you need for a mid-drive motor conversion kit. As long as the bike you are starting with has a bottom bracket sized between 68 and 73mm, this kit will work. From there you can choose the front chainring size, the battery size, and what display works for you.

Bafang front wheel conversion kit

(Image credit: Josh Ross)

Bafang Front Hub Motor kit and Battery

Stick with a well-known brand but opt for the ease of setup that comes with a front wheel motor

Specifications
Wattage: 250, 500, 750
Battery included: Yes
Motor position: Front wheel
Reasons to buy
+Relatively easy setup+Powerful once converted+High quality components+Great ride quality+Control for every component is in your hands
Reasons to avoid
-Cable management is a challenge

If you like the idea of converting your bike to electric-assist but you can't, or don't want to, deal with the added complexity of a mid-drive setup, then the Bafang Front Hub kit makes things much easier. 

Like the mid-drive system listed above, the Front Hub Kit covers everything you need and gives you tons of choice. Start by choosing your wheel size and display preference, then add the battery size and shape you'd like. 

With all the options available, finding the kit to fit your bike is easy.

Swytch Electric Bike Conversion Kit

(Image credit: Josh Ross)

A clever and attractive kit that is easy to install on almost any bike

Specifications
Wattage: 250
Battery included: Yes
Motor position: 250 wheel
Reasons to buy
+Shows battery power and assistance mode+The hub is available without a wheel for something unique+Easy to take the battery pack with you and avoid theft
Reasons to avoid
- Cadence sensor can be hard to fit 

Swapping the front wheel is one of the easiest ways to convert any bike to an electric bike. That's the approach that Swytch takes but a good system is more than just a motor and battery. The Swytch kit thinks through the whole system. The battery mounts to the handlebars and it's easy to take with you so it doesn't get stolen. While riding there are lights on the top of the battery pack to show how much battery you've got and what assist mode you are in. There's also a cadence sensor that attaches to your bike. It's a well thought out system and it looks great. 

Rubbee X electric bike conversion kit

(Image credit: Josh Ross)

The absolute simplest install possible

Specifications
Wattage: 250w
Battery Included: Yes
Battery Position: Rear tire
Reasons to buy
+Regenerative braking+Wireless Cadence Sensor+Incredibly simple to setup and easy to remove
Reasons to avoid
-Motor makes noise on the tyre, especially in the rain

There are a number of simple install options on the list but the Rubbee X takes it a step further. Attach a mount to the seat tube and click the unit into the mount. There's also a cadence sensor but that's wireless too. There's nothing easier than that and you get a slick looking 250watt motor with a single battery in the base kit. If the 10-mile range of the base unit feels a little constricting add another battery and double the range. If you need to change assistance modes, grab your phone and open up the app.  

Pendix eDrive150start

(Image credit: Pendrix)

Pendix eDrive150start

The advantages of a torque sensing mid-drive kit with a dealer network for installation and support

Specifications
Wattage: 250w
Battery Included: Yes
Motor Location: Crank
Reasons to buy
+Fits most bikes with a threaded bottom bracket+Torque-sensing pedal assist+Dealer installed
Reasons to avoid
-Expensive-Must be fitted by a dealer

If you like the idea of a mid-drive system and you want it to have torque-sensing pedal assist then you've got a couple of choices. The challenge with a system like that is complexity. For some people, it's no big deal to take apart a bottom bracket but for others it's intimidating. 

The Pendix system does the same thing as other kits but it has a dealer network that handles sales, support, and installation. This comes with an extra cost attached, but the benefit is that you can feel comfortable that the system is correctly installed and your bike is ready for it. 

Tongsheng Mid-Drive Kit with Battery

(Image credit: Tongsheng)

Tongsheng Mid-Drive Kit with Battery

A torque sensor-based pedal assist with a mid-drive motor is the gold standard for natural feeling acceleration

Specifications
Wattage: 500
Battery included: Yes
Motor position: Crank
Reasons to buy
+Torque sensor-based pedal assist+Natural feeling acceleration
Reasons to avoid
- Instructions aren’t great

The most natural-feeling motor is going to be a mid-mounted motor. If that works for you and you also like the idea of doing some pedalling, then the very best is a mid-mounted motor paired with a torque sensor. 

Instead of the system knowing you are pedalling and adding power, a torque-based system adds a percentage of power. Max torque available on this system is 80Nm but depending on your chosen assist level, that 80Nm will add between 36 and 300 per cent to your pedalling power. 

To keep it simple, think about it as an amplifier. If you pedal harder you go faster, just like a normal bike, but now your muscles have extra support. 

How to choose the best electric bike conversion kit

Make sure you get a battery

There's not a huge explanation needed for this. You need a battery, so make sure the kit you select has it. Not all kits include it, so if you find yourself browsing through options and landing on something with an unbelievable price, just double check it's included. It is possible to source the battery yourself but be sure about what you are getting.

Types of e-bike conversion kits

Friction Drive Conversion

A roller pushes against the tyre on the wheel and when the roller turns the wheel turns. This strategy isn't all that efficient but it's simple. There's very little challenge with making it work but at the end of the day, it doesn't work all that well. 

Mid-Drive Conversion

The best electric bikes tend to be mid-drive and the same is true of conversion kits. The weight sits low in the frame and the power gets applied to the crank for a more natural sensation. The only downside is pricing and packaging. Different standards make it challenging to figure out exactly what you need and there's more work involved in adding the parts. 

Electric Bike Wheel Conversion

Swapping either a front or rear wheel for an electrified version is a good balance. The conversion process is very simple and depending on how the battery mounts the weight distribution can be quite good. Powering the wheel does change the way the power delivery feels and making the front wheel heavy can affect the handling of the bike. If mid-drive seems overwhelming this is an excellent option. 

Consider unknown brands

In the world of electric bikes there are a lot of brands you may not have ever heard of. There is a boom going on so new brands are popping up all the time. Not only that but Europe, and especially the US, are playing catch up to the trend of electric bikes. You will probably stumble across a lot of unfamiliar brand names. 

Consumers have a tendency to look away when they encounter a new brand. It's not a bad strategy but in the electric bike world, including conversion kits, you've got to be more open than that. If you aren't open to names you've never heard of you will find the options limited. A lot of the names you may come across are unfamiliar to you but have a solid history behind them.

That doesn't mean you should go forward blindly. Do your research and be careful with your money like always. The only thing that might be different is a need for being open to new companies. At the very least be willing to look a little deeper, read reviews, do some research. The brand you've never heard might actually be a well-established brand from a different part of the world. 

Should you buy an electric bike instead?

Remember to consider all your options. You have a bike in the shed you haven't touched for a lot of years. It seems like a perfect candidate for conversion to an electric bike. It might be, but it's also just as possible that it's a better candidate for a sale. Sometimes it's better to take the money from that sale, and put it towards an electric bike someone else built. 

As with anything, consideration for the end-use during design and build can have advantages. A quality electric bike conversion kit might end up being very close to the price of a complete electric bike. If a company starts with a clean slate and designs an electric bike it's easier to keep costs low and integration high. Really consider why you are thinking about converting your bike and does it make sense compared to what's on the market. In some cases it will but in others, it won't.

Consider the condition and componentry of your old bike as well. With an electric motor dramatically increasing the torque, using a low quality or worn drivetrain will result in poor performance with shifting being affected and the chain skipping or even snapping. Another important consideration is the brakes, adding the extra weight and increasing potential speeds put more stress on the brakes as they try to curtail momentum. We recommend choosing to convert a bike that has disk brakes as they will provide far better braking performance.

Don’t forget local laws

Whatever kit you end up deciding on make sure you have an understanding of the local laws that govern electric bikes. Given the connected nature of our global economy, it's possible to buy kits you can't use where you want to. It's also important to understand how you can use the new electric bike you have. Depending on the kit, and its power, you may not be welcome on bike-only infrastructure. Make sure you understand what you are buying and consider how and where you want to use it.  

Individuals carrying out the instructions in this guide do so at their own risk and must exercise their independent judgement. There is a risk to safety if the operation described in the instructions is not carried out with the appropriate equipment, skill and diligence and therefore you may wish to consult a bike mechanic. Future Publishing Limited provides the information for this project in good faith and makes no representations as to its completeness or accuracy. To the fullest extent permitted by law, neither Future Publishing Limited, its suppliers or any of their employees, agents or subcontractors shall have any liability in connection with the use of this information, provided that nothing shall exclude or limit the liability of any party for personal injury or death caused by negligence or for anything else which cannot be excluded or limited by law.   

Josh Ross

Josh hails from the Pacific Northwest of the United States but would prefer riding through the desert than the rain. He will happily talk for hours about the minutia of cycling tech but also has an understanding that most people just want things to work. He is a road cyclist at heart and doesn't care much if those roads are paved, dirt, or digital. Although he rarely races, if you ask him to ride from sunrise to sunset the answer will be yes.
Height: 5'9"
Weight: 137 lb.
Rides: Look 795 Blade RS, Cannondale Topstone Lefty, Cannondale CAAD9, Trek Checkpoint, Priority Continuum Onyx