Electric bike conversion kits 2024: Add a motor to your bike

E-bike conversion kits Why pay for a brand new e-bike when electric bike conversion kits can easily give a boost to the bike you already have? E-bikes have enabled people who need or want some pedal assistance to broaden the range and scope of their riding while making it easier than ever to choose sustainable and greener transport methods.

Whatever your reason for wanting pedal assistance - whether it makes cycling more accessible to you and your family, or you think you'll have more fun with that boost - the e-bike market is vast and often requires a large upfront cost.

So if you're struggling to find an e-bike that suits you, and already have a bike at home that's suitable for conversion, then you might consider an electric bike conversion kit instead.

Whichever option you go for, there's no denying that the best electric bikes[1] make it easier for riders to explore and experience different terrains and riding environments. Plus they offer a cheaper and greener form of transport to get you from A to B at a higher pace for less effort than a conventional bike, which is especially beneficial for those who are commuting or using them for work. The best electric bikes for commuting[2] can make for a speedier and altogether less sweaty cycle to work, not to mention the money saved when compared to soaring fuel or rail fare prices.

But what if you're not sure about which option to go for?

If you're weighing up an e-bike vs an e-bike conversion kit[3], consider whether you already have a bike that you love riding. Converting it means you can continue enjoying the same ride quality while introducing you to a new world of electrically-assisted fun.

To make all these decisions easier for you, we've outlined in our buyer's guide lower down this page the key things to consider when fitting an electric conversion kit to your own bike, including the various motor and battery options available. We've tested as many as possible in real-world riding conditions, assessing how easy they are to fit, and what kind of electric assistance they provide.

So here are our findings, and our roundup of the best electric bike conversion kits you can buy right now.

Best e-bike conversion kits: Quick list

Best overall

[4]

1.

Cytronex Well-thought-out design, engineering and easy installation with a couple of Allen wrenches. Intuitive operation, app-based diagnostics and great UK-based customer support.

Smooth ride quality and easy mode choice too!

Best budget

[6]

2. Bafang Front

A simpler alternative to mid-drive setups. Customizable specs for wheels, displays, and battery sizes. Powerful motor and high-quality construction.

Installation is more complex, but it's excellent value.

Easy installation

[8]

3. Rubbee X

Effortless installation; it simply attaches to the seatpost. The 250-watt motor propels a roller that moves the rear tyre, and assistance adjusts based on your pedalling. Three models offer three battery options, and an app tailors assistance modes.

Blend in

[10]

Easy conversion by replacing the front wheel with a motorised one. Includes a convenient handlebar-mounted battery, and an LCD display in place of buttons, which makes it easier to see your battery level and more.

Configuration

[12]

5.

Bafang Mid Comprehensive mid-drive conversion kit suitable for bikes with a bottom bracket size between 68 and 73mm. Customization options for front chainring size, battery size, and display preferences.

Dealer support

[14]

E-bike conversion kits can be complex to install, so Pendix works with a dealer network for sales, installation and support, ensuring correct installation and peace of mind, albeit with an additional cost.

Best electric bike conversion kits available now

You can trust Cyclingnews Our experts spend countless hours testing cycling tech and will always share honest, unbiased advice to help you choose. Find out more about how we test.[16]

Recent updates

The electric bike conversion kit market is quite dynamic, with brands entering and exiting it regularly. All the options listed below are from established brands though, and we've checked the continued availability of these electric bike conversion kits as of April 2024 and updated this guide accordingly.

Best e-bike conversion kit overall

The Cytronex e-bike conversion kit attached to a lightweight Brompton folding bike (Image credit: Josh Croxton)

Best overall design

Specifications

Wattage: 250 watts

Battery included: Yes Battery size: 198Wh Motor position: Front hub

Reasons to buy

+

Thorough attention to detail in the design

+

A clever battery setup maximises power while ensuring it's cheaper to deliver and safe for flying

+

Easy to operate the controls while riding

+

The accompanying app offers basic diagnostics

+

Installed using nothing but Allen keys

Reasons to avoid

-

A thorough purchase process ensures the right configuration is easy to select, but it's complicated to install so can take time

The first on our list is one which really impressed us.

The Cytronex electric bike conversion kit is extremely well thought-out, with great specs and top-notch engineering. You only need Allen keys to install it, it comes with an accompanying app to offer up basic diagnostics, and once it's set up it's a breeze to operate.

When purchasing, you'll go through a thorough process, which can feel a bit over-complicated, but in doing so it means the actual conversion is a straightforward one. We tested out the Cytronex on a Brompton T-Line and found it delivered smooth and intuitive power.

Plus, our hands-on time with it leads us to believe it's strong and durable enough to use for commuting.

While it's pricier than some of the options listed below, one thing to consider is that it comes from a UK-based company that offers comprehensive customer support. You can pay less for a Bafang kit on Amazon, but buying direct from a company that can support you if anything goes wrong, makes it a smarter choice in our view.

For an in-depth look, check out our Cytronex[17] review.

Best budget option

It's not subtle, but the huge battery on the rear rack provides a huge range (Image credit: Josh Ross)

Most powerful electric bike conversion kit

Specifications

Wattage: 250, 500, 750 watts Battery included: Yes

Battery size: Varies, 840Wh as tested Motor position: Front hub

Reasons to buy

+

Relatively easy setup

+

Powerful once converted

+

High-quality components

+

Control for every component is in your hands

Reasons to avoid

-

Cable management is a challenge

If you're on a tighter budget than the Cytronex or Swytch allow for, then as we mentioned above, getting a kit from Chinese manufacturer Bafang may be a better option. Plus, if you like the idea of an electric bike conversion kit but just don't want to have 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 below, the Bafang Front Hub Motor kit covers everything required and gives tons of spec choices.

We started by choosing our wheel size and display preference, then added the battery size and shape we wanted.

We did find it more of a time investment, given the installation process was more complex than the Cytronex, Swytch and Rubbee, but this did allow us to achieve a powerful, high-quality set-up.

To find out more about how we got on, read our Bafang Front Hub Motor[18] review.

Best for easy installation

This is the easiest e-bike conversion kit to install, by far (Image credit: Josh Ross)

Best for easy installation

Specifications

Wattage: 250 watts Battery included: Yes Battery size: 94Wh / 186Wh / 272Wh (tested)

Motor position: Rear tire

Reasons to buy

+

Regenerative braking

+

Wireless cadence sensor

+

Incredibly simple to set up 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 this list but the Rubbee X takes it a step further. We were really impressed with how easy it was to attach the mount to the bike's seat post and then click the unit into the mount. There's no need to change the wheel as with the Swytch system.

Here the motor sits on top of the rear tyre and a roller pushes it around from above. There's also a wireless cadence sensor, as this is a cadence-based system that adjusts based on pedalling cadence, rather than torque.

There is a slick-looking 250-watt motor with a single battery in the base kit. If the 10-mile range of the base unit feels a little constricting, another battery can be added to double the range, or a three-battery model adds both extra range and another 100 watts of power.

Rubbee also has a handy phone app that can be used to change assistance modes.

We've spent some time testing it out, so why not check out our Rubbee X[19] e-bike conversion kit review for more details.

Blend in - it just looks like a normal bike

From afar, you probably wouldn't notice this is an electric bike (Image credit: Josh Ross)

Best for blending in

Specifications

Wattage: 250 watts Battery included: Yes Battery size: 90Wh / 180Wh

Motor position: Front hub

Reasons to buy

+

Battery is tiny

+

Pleasant ride

+

Easy to move to a different bike frame

+

Inexpensive as long as you are patient

Reasons to avoid

-

The ordering process can feel convoluted

-

Short range

One of the easiest ways to convert a bike to electric is to swap out the front wheel for one with a front hub motor. This is the approach that Swytch takes, but there's more to a good system than just a motor and battery. From our time testing and reviewing it, it's clear to us that the team behind Swytch has considered the whole system in its design.

The battery mounts to the handlebars and we found that a really useful detail.

It is easy to disconnect and take it away for storage, so it doesn't get stolen when you are out and about, or to lighten the bike when, for example, it needs to be carried up a flight of stairs.

The 2022 Swytch system, which we tested, makes use of a neat handlebar-mounted LCD display instead of the buttons on the battery it had before. There's also a cadence sensor that attaches to your bike. It's a well-thought-out system that looks and feels great.

To read all about how it works, and find out why we gave it four stars, take a look at our Swytch[20] review.

Easy and plentiful configuration

The mid-drive kit mounts to the bottom bracket of your bike (Image credit: Bafang USA)

5.

Bafang Mid-Drive Motor Kit and Battery

Best for custom configuration with different motors, displays and more

Specifications

Wattage: 500 watts Battery included: Yes

Battery size: Varies Motor position: Crank

Reasons to buy

+

US specific support

+

Lots of kit options

+

One of the most experienced conversion kit manufacturers

Reasons to avoid

-

Instructions could be more detailed

-

68-73mm bottom bracket shells only

Bafang is one of the largest and best-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 far 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.

If you're not sure whether or not a mid-drive motor conversion is what you need (or what other drive options there are), head down to our FAQs at the bottom of this article for an explanation of all the possibilities you can choose from.

Best for bike shop support

The Pendix ebike conversion kit must be installed by a professional mechanic, who will also provide aftersale support (Image credit: Pendix)

6.

Pendix eDrive 300

Best if you want the support of a dealer network

Specifications

Wattage: 250 watts Battery included: Yes

Battery size: 330Wh Motor position: Crank

Reasons to buy

+

Fits most bikes with a threaded bottom bracket

+

Torque-sensing pedal assist

+

Dealer installed

Reasons to avoid

-

Not allowed to fit it yourself

-

Dealer installation may come at a cost

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 few 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 a slightly more intimidating prospect.

The Pendix system does the same thing as other kits but there is 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 ready to ride.

Best for natural ride feel

The Tonsheng offers a torque-based sensor, offering the most comprehensive ride feel of the bunch (Image credit: Tongsheng)

7. TongSheng Mid-Drive Kit with Battery

Best for a natural ride feel

Specifications

Wattage: 500 watts Battery included: Yes Battery size: Varies

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 electric bike conversion kits are going to be those with 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, such as the Rubbee X cadence-based system above, a torque-based system adds a percentage of the power you are putting into your pedalling. The Max torque available on this TongSheng 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, so you can go further with less effort.

Types of e-bike conversion kits

Friction drive conversion

A friction drive e-bike conversion means there is a roller that pushes against the wheel's tyre. So when the roller turns, the wheel turns. It's not the most efficient strategy, but it's simple and it works.

There is very little involved with regard to making it work but, at the end of the day, it doesn't work as well as other systems out there. The Rubbee X is an example of a friction drive conversion kit system.

Mid-drive conversion

The best electric bikes tend to be mid-drive because this delivers the most natural ride feel, 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 power delivery sensation.

The only downside is pricing and packaging, plus it can be complex to set up yourself. Different standards make it challenging to figure out exactly what you need, as well. The Bafang Mid Drive Motor Kit is an example of this.

Electric bike wheel conversion

Swapping either a front or rear wheel for one with a hub-mounted motor 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.

Cytronex and Swytch are examples of this.

How to choose the best electric bike conversion kit for you

If you're interested in fitting an electric bike conversion kit to one of your own bikes, you should consider your own personal requirements first and do plenty of research. You're in the right place, as this guide will help you with a lot of that.

Before anything, familiarise yourself with the laws regarding e-bikes in your region. Then you may want to choose a conversion kit based on your range and journey needs.

If you live in a hilly city, for example, you may want something with a little more top-end power. Lastly, check whether or not the system is compatible with the bike you plan to fit it onto. If you don't feel comfortable doing this yourself, think about getting a quote for installation from a reputable bike shop.

Do all electric bike conversion kits come with a battery?

The short answer is 'not always'.

You need a battery, of course, so when browsing online, make sure the kit you select has one included. Since not all kits include a battery, you might find yourself browsing through options and landing on something at an unbelievable price. If that's the case, double check it's got the battery included.

If not, then it is possible to source the battery yourself, but be sure about what you are getting. The battery voltage and output need to match the motor. It's really important to make sure that your charger is compatible too; charger incompatibility is cited as a cause of many fires caused by electric bikes.

What is the range of an e-bike conversion?

It depends, and that's why we've not quoted it for each kit listed above.

Instead, we've included the battery size and motor power, to help you get a fair gauge of how one compares to the next. To help you understand why that's relevant, a quick basic formula: A 100Wh (Watt-Hour) battery will last for one hour when the motor is putting out 100 watts of power. Different products come with different battery sizes and various motor powers, but as an example, if your e-bike conversion kit has a 250-watt motor, and it has a 500Wh battery, it will last for two hours at full power.

To then convert that into a distance (to be able to quote a range) is even more confusing. Riding uphill will use more power but be slower than riding downhill, so you'll cover different distances for the power output depending on where you live and the terrain you'll cover. What's more, one person may use full power sparingly, whereas another will use it everywhere.

And finally, if it's cold, batteries perform worse than if it's warm, so will drain more quickly in winter than in summer. With all that said, in our experience, a 200Wh battery paired with a 250w motor will get you around 25-30km when used on mixed terrain with a mixed use of power outputs. Some battery options will have much larger capacity than this though.

Long-range electric bike conversion kits might give you around three times this range, although the battery will be larger and heavier and cost significantly more.

How fast do electric bikes go?

This is hard to answer specifically as electric bikes are, on the whole, designed to assist pedalling rather than replace it, and it is the same with electric bike conversion kits. The measurement of the power of the motors is in wattage and, in effect, the higher the wattage of the motor, the faster speeds it will be capable of achieving. However, the speed is often limited as a result of country-specific regulations.

In the UK, the assistance an e-bike can legally provide is up to 25kph (15.5mph) and, after that point, the bike can go faster but without any assistance from the motor. Anything faster would not meet the UK's electrically assisted pedal cycles (EAPC) criteria[21], would be classed as a moped or motorcycle, and need to be licensed and taxed appropriately. The same is true in the EU.

The laws are different depending on the country, with the United States, for example, allowing more powerful motors for some e-bike classes[22] - although individual states have their own legal frameworks.

Which bike is best for electric conversion?

You should consider the condition and componentry of your old bike. 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 of an electric bike conversion kit and increasing potential speeds will put more stress on the brakes as they try to curtail momentum. We recommend choosing to convert a bike that has disc brakes as they will provide far better braking performance.

I haven't heard of a lot of these brands, are they safe to use?

In the world of electric bikes, there are a lot of brands you may not have ever heard of. There's been a boom going on for a while, 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 most of the time 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 will be 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 the need to be open to new companies.

At the very least be willing to look a little deeper, read reviews, and do some research. The brand you've never heard of might actually be a well-established brand from a different part of the world.

Is converting my bike to an electric bike worth it?

There are plenty of reasons to install an electric bike conversion kit to your current bike, but the question of whether it's worth doing is going to depend on your circumstances. For many kits, once the installation has been completed, it will be an arduous task to remove it again, so one of the questions you'll need to ask yourself is whether or not you want to retain the ability to use the bike as a 'normal' bike.

If you expect to be flitting between powered and non-powered then a kit that can simply be folded out of the way - like the Rubbee X - might be perfect, but you might instead prefer to simply buy a second bike for the convenience. The second question is to assess the state of your current bike. If you don't yet have one, then the cost of buying a bike, buying an electric bike conversion kit and then fitting it, is probably not going to be worth the time, effort, or money involved.

However, if you have a bike that is in reasonable repair, then the value for money - and effort - will be greater. Beyond the financial and practical element, the question of 'is it worth it' will also depend on the amount of use you get out of it. E-bikes can be incredibly motivating and enjoyable and if converting your standard bike to electric helps you to ditch the car on a regular basis, then the answer becomes clear.

If you want a monetary answer to this question, then there are ways to work out whether the investment is worth it. Take a moment to think about your current car usage and work out the cost per day/mile, including fuel, parking and running costs. Try to work out how many journeys, days or miles you will use the bike for after it is converted.

Once you know this, you should be able to work out the reduction in car running costs per mile/day and, with that, you should be able to work out how many miles/days it will take for the electric bike conversion kit to pay for itself.

Should I just buy an electric bike instead?

Remember to consider all your options. You have a bike in the shed you haven't touched for many years and 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 of 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 whether it makes sense compared to what's on the market. In some cases, it will but in others, it won't.

Are electric bike conversion kits legal?

The kits themselves are entirely legal, and fitting them to your bike is equally so.

However, the question of legality arises in relation to where you then plan to use your newly powered electric bike. The answer will vary hugely, depending on where in the world you're based, and which kit you choose. For example, in the US, there are different classes of e-bikes that vary by their power, speed limitations and whether or not they have a throttle, and each class is subject to different rules.

Things are a little more simple elsewhere, with the UK and EU stating that anything with a speed limiter of over 25km/h is classified as a moped, while anything up to 25km/h (15.5mph) is classed as a bicycle. Before you complete any purchase, make sure you have an understanding of the local laws that govern electric bikes, which is where our guide to e-bike classes[23] comes in handy. The best legal electric bike conversion kit will vary by where you are based.

In the UK and EU, a motor has to have a continuously rated power output of no more than 250 watts, whereas in the US a more powerful electric bike motor can be used. There are also higher speed limits for assistance in the US and an electric bike conversion kit can include throttle control, whereas elsewhere it needs to be pedal actuated.

Which are the fastest electric bike conversion kits to install?

Sadly, there is no single and simple answer to this question. Each electric bike conversion kit works in a different way and therefore fits onto your bike in a different way too.

The most simple options, and thus the fastest electric bike conversion kits to install, are the friction-drive kits, such as the Rubbee X[24], which place a roller onto your rear tyre. In the example of the Rubbee, you simply need to mount the device onto your seat post, with the roller placed against the tyre. However, more complex systems require the removal of drivetrain components and wheels, and the installation of wiring.

These are far from impossible, but they may require some tools and a bit of patience. In general, a kit which includes a replacement wheel is likely to be faster to install than one that sits in your bottom bracket, as removing your old wheel and fitting a new one is relatively straightforward. It's then a question of bolting the battery to your frame and cabling the two up, along with any extra control units and sensors included in the kit.

How much does an electric bike conversion kit cost?

Prices will depend very much on the conversion kit in question.

Some are available for as little as GBP250 (£350), while the more high-spec and integrated kits can fetch as much as GBP750 (£900) or more. An e-bike conversion kit will add significantly to the value of your bike and, if it's easy to install, it's also easy to remove. It's worth considering insuring your e-bike conversion kit[25], just in case.

Will a bike shop fit my electric bike conversion kit?

It's understandable that you might not want to take on the arduous task of fitting your electric bike conversion kit yourself.

You might not have the tools, the know-how, the confidence, or simply the time to invest. Luckily, almost all bike shops will be happy to fit it for you. Some systems, such as the Pendix kit listed above, are only sold via physical stores and the fitting is sold as part of the overall package.

However, with kits bought online such as the Bafang kit, the shop will charge you for the time it takes, which will add to the cost of the overall conversion. In our opinion, knowing that it's been done correctly and safely is worth spending extra. Some bike shops or workshops may refuse to install a conversion kit to a bike they consider unfit for purpose or potentially unsafe.

If you plan to have your local shop fit a kit it may be worth consulting with them on the job first to make sure they are happy to do it for you.

How do we test the best electric bike conversion kits?

Like all of our buying guides, our advice is gained through countless hours of using products in the real world, often back to back against their peers to compare them, but ebike conversion kits have an additional need. If a conversion kit is too tough to install, it will cost you more as you seek the help of a professional. Therefore, with our testing, we also spend time fitting the kit to the bike in the first place, judging how long it takes and how intuitive it is.

Once that's done, we do the real-world testing, judging the range, the ease of use and the durability of the product in question.

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.

References

1. ^ best electric bikes (www.cyclingnews.com)
2. ^ best electric bikes for commuting (www.cyclingnews.com)
3. ^ e-bike vs an e-bike conversion kit (www.cyclingnews.com)
4. ^ Best overall (www.cyclingnews.com)
5. ^