You can add a motor to an existing bike with the best electric bike conversion kit. It is easy and inexpensive – at least when compared to buying an entirely new electric bike. There are a growing number of ebike converter kits available. They’re becoming more advanced and easier to fit on your bike. This makes them a viable alternative to buying a brand new electric bike.
A kit for converting an electric bike to an electric bike will contain the motor and battery. It must also include an apparatus to adjust the power output. This is usually a bar-mounted display.
A kit will include sensors that detect your speed and pedal input, to ensure you get the right power supply.
All electric bike conversion kits must stop when you aren’t pedalling. They also need to travel at 25kph in Europe, Australia, and the majority of the rest of Europe. This is 20mph in the USA.
BikeRadar has tested several electric bike conversion kits, but we have yet to test many more. Stay tuned for our full review of the top electric bike conversion kits.
You can find a detailed explanation of each type of kit in our explainer, further down the page.
The best electric bike conversion kits for 2022
Kit for Swytch conversion of an electric bike
Pros: Compact, easy-to-install, a wide range of options
Cons: Only 100mm threaded for front axle, not compatible with thru-axles
Swytch, a London-based company, makes a 3kg conversion kit. It converts any bike into an electric bicycle.
This kit comes with a 40Nm brushless hub motor-based motor and a replacement front wheel. The lithium-ion battery pack attaches to your handlebars and acts as both the system controller, LCD display and controller. A crank-mounted cadence sensor is all that’s needed to attach to your bike.
A Brompton-specific kit is also available, which includes an adaptor to the Brompton front luggage mount.
There are three types of battery packs available depending on how far you need to travel. They have a range of 35km, 50km, and 100km.
Swytch recently introduced a smaller kit that is just 700g in weight and gives you 15km range. Pre-orders will open soon for the new kit. However, the Swytch existing kit will still be available until late summer 2022.
Kit for Cytronex electric bicycle conversion
Pros: Smart sensor technology, decent range
Cons: There is not much information on the range and battery level on the onboard display.
The Cytronex Cytronex Ebike Conversion Kit weighs between 3.2kg to 3.6kg. It is another front-wheel conversion that houses a hub motor. However, in this case the battery can be fitted in a standard bottles cage.
The kit was tested on a Cannondale Quick hybrid. We estimate that the conversion takes about 30 minutes. The battery’s LEDs display the charge level and also house the controller. A single charge can get you up to 48 miles.
The kit was also tested on a Brompton P Line lightweight file folder. It weighed less than the C Line-based Brompton Electrical. It can be fitted to a C Line, which is also less expensive than the Brompton electric.
Electric bike conversion kits: different types explained
You have a few options to electrify an existing bike to assist you up the hills. One is to attach a power unit to the bottom bracket. Another option is to mount a motor above the rear wheel to drive it via friction. Or, perhaps most cleverly, to hide the motor under the seatpost.
It doesn’t matter if you are a hybrid, mountainbike, road bike, or even a folder or tourer, it should be possible for your bike to be converted.
If you feel confident and have some spare time, many can be fitted by a qualified home mechanic.
What are your options? Let’s look at some of the options available to convert your non-assisted bicycle into an electric one.
Powered ebike bikes
A powered ebike wheel is the best option. You can swap your non-powered wheels to fit a hub with a motor and add a battery. The bike is powered by an oversized hub and a strap-on battery.
Although it sounds easy, the downside is that you will have to add rotating mass to your bike. This makes it harder to accelerate than non-rotating.
Kit for rear-mounted friction drive ebike conversion
Some readers may recall earlier versions of this box in the 1980s/90s. It sits on your rear wheels and is powered by friction using a rubber flywheel that is driven by a motor.
It hasn’t died, and the idea lives on in devices like the Rubbee that promise bolt-on electric assistance to nearly all bikes.
Rubbee’s base model is only 2.8kg in weight, and can travel 16km, but it can also go up to 48km with its top-spec, 4-kg version.
This wheel can be used with any diameter wheel between 16in to 29in. It also has an integrated carrying handle that clips onto your seatpost. Prices starting at EUR579.
Concealed ebike converter kit
The Vivax Assist concealed a motor inside the seat tube and applied power directly at the crank.
Vivax
We now come to the simple way: hide a motor in your bike so that no one can find it.
Although the Vivax Assist is no longer in business, it was the most well-known device. Femke Van den Driessche, a Belgian Cyclocross Pro, used the Vivax Assist system to power her victory at her home championships in 2016. After being discovered at a subsequent race she was banned for six years and forced to quit racing.
Although Vivax Assist is no longer available, we think this idea still has legs – at the least for budding cyclocross competitors.
Kit for mid-drive ebike conversion
Motors can be found on many ebikes that are commercially available. They are located near the pedals and around the bottom bracket.
These bikes have the added advantage of putting the weight lower on the bike which makes it more stable.
You don’t have to buy a pre-made option. Aftermarket conversion kits can be purchased with mid-drive units.
Bafang, a brand that focuses more on complete ebikes but also offers a mid drive conversion kit on Amazon as well as hub motors.
Bafang claims that the conversion costs only PS360 and requires just a few tools to complete.
As previously mentioned, throttle-controlled kit that doesn’t comply with UK ebike regulations will be illegally considered a moped.
Amazon also sells other mid-motor systems, such as the TongSheng unit, which claims to fit 95% of standard bicycle frames and is 30% lighter than a Bafang one.
The torque sensor is used, so it should be within the ebike regulations. It costs around PS350, but does not include a battery.
Folding ebike conversion kit
Brompton electric conversion by Electric Concepts is just one of the many options available to electrify an already existing Brompton.
Electric Concepts
What should you do if your folding bike isn’t working and you want to be part of the electric revolution?
There are many ebike conversion kits available for Brompton owners. These kits work with a powered hub on the front wheel and a bag that holds the battery.
Both Cytronex and Swytch can be used to convert Bromptons, as we have already discussed. The Brompton kit from Swytch is priced at PS999. However, there are discounts up to 50% sometimes.
Like the other systems, it has a front wheel motor, a clip on power pack, and a bottom bracket torque sensing. The quoted range is approximately 50km.
Swytch can also make wheels for folders using different wheel sizes and fork blade widths such as Dahon’s models.
