Skip to main content

Electric conversion kits for mountain bikes: Power up your existing bike

Bafang Mid-Drive Mountain Bike Conversion Kit
(Image credit: Bafang USA)

If you've had a bike kicking around for a while but your fitness isn't where you want it to be there's no reason to let that stop you - there are some options available. The promise of electric bikes is longer days, faster speeds, more climbing and less work. The best electric mountain bikes represent a great way to get into the sport for the first time, not to mention help reduce exercise intensity if you're on a recovery day or coming back from an injury.

To make things even easier you can convert the bike you know and love. It's yet another way of lowering the barrier of entry. Instead of taking a risk on a new bike, work with what you've got. Keep reading to see a list of electric bike conversion kits that will work on a mountain bike or jump down below to see a few things worth considering.

Electric conversion kits for mountain bikes

Bafang Mid-Drive Motor Kit and Battery

(Image credit: Bafang)

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 : 500w
Battery included : Yes
Motor position: Crank

Reasons to buy

+
US support
+
Lots of options

Reasons to avoid

-
Needs better directions

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 Bafang components. 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.

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: 500w
Battery included : Yes
Motor position: Crank

Reasons to buy

+
Torque sensor based pedal assist
+
Smooth power delivery

Reasons to avoid

-
Needs better directions 

The most natural feeling motor is going to be one of the mid-mounted kind. If that works for you and you also like the idea of doing some pedaling, then the very best is a mid-mounted motor paired with a torque sensor. A torque-based system adds a percentage of pedal power to your cadence. Max torque available on this system is 80Nm but, depending on your chosen assist level, that 80Nm will vary assistance between 36 and 300%. 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. Not only does this feel natural but it’s gentler on trails making it an especially great option for a mountain bike. 

CYC X1 Pro Gen 2 mid-drive motor

(Image credit: Cyc Motor)

CYC X1 Pro Gen 2 mid-drive motor

A seriously high-end mountain-bike-specific system

Specifications

Wattage: Up to 5000 watts and adjustable for regulations
Battery included: No
Motor position: Bottom bracket

Reasons to buy

+
Handles huge power and torque
+
Easily adjustable to meet local regulations
+
Wide compatibility

Reasons to avoid

-
Expensive
-
Doesn’t include a battery

If you are looking to do some serious trail riding this is your kit. Instead of mounting the motor below the bottom bracket, you can keep it up and out of the way for the best ground clearance. Even with that provision, it still fits common standard and fat bike bottom brackets including BB92.  Just like other high-end systems from rival brands, the Cyc X1 pro uses both cadence and torque sensors for the most natural-feeling ride. It does not include the battery in the kit, but, the system is capable of up to 5000 watts of power (battery dependent). If you want to keep things street legal, there's an app to match your bike to your local legal limit.   

Bafang Front Hub Motor kit and Battery

(Image credit: Bafang)

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: 500w
Battery included: Yes
Motor position: Front wheel

Reasons to buy

+
US support
+
Lots of options
+
Easy install

Reasons to avoid

-
Power delivery is abrupt 

If you like the idea of something from Bafang but you'd rather look beyond a bottom bracket conversion kit, then this is an option. With mountain bikes, a bottom bracket installation might have clearance issues on the trails. It's also always going to be more difficult than just swapping a wheel. With the front hub conversion kit all you have to worry about is getting the right size wheel. Fortunately, there are options for 26-, 27.5-, and 29-inch wheel sizes. Whatever you need, Bafang has a way to make it work.  

Swytch Universal Electric Bike Conversion Kit

(Image credit: Swytch)

Swytch Universal Electric Bike Conversion Kit

A clever and attractive kit that is easy to install and follows European regulations

Specifications

Wattage : 250w
Battery included: Yes
Motor position: Front 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 

As already discussed, swapping the front wheel is one of the easiest ways to convert any bike to electric. The Swytch Universal Electric Bike Conversion Kit mounts the battery to the handlebars so it's easy to remove and won't get stolen. There are integrated lights on the top of the battery pack to show how much charge you've got as well as let you know the level of assistance. There's also a cadence sensor that attaches to your bike. It's a well thought out system that looks great and conforms to EU regulations. 

Cytronex C1 Electric Bike Conversion Kit

(Image credit: Cytronex)

Cytronex C1 Electric Bike Conversion Kit

A battery that looks like a water bottle, with options for US or EU compatibility

Specifications

Wattage: 250w
Battery included: Yes
Motor position: Front wheel

Reasons to buy

+
Shake the battery to show charge
+
Disc- or rim-brake versions
+
Possible to wire lights into the system

Reasons to avoid

-
No mobile app 

The C1 kit from Cytronex offers another take on the front wheel concept. There are three pieces to the kit and it's available pre-installed on a bike or on its own. The kit will include a motor that conforms to the regulations applicable so be sure to select whether you're based in the UK, EU or US before buying. Then, choose if your bike has disc or rim brakes and select the correct wheel size. The battery sits where a water bottle would normally go and the rider interacts with the system through a control button. It's easy to install and some people will even be able to take advantage of the factory installation package.   

Rubbee X ebike conversion

(Image credit: Rubbee)

Rubbee X

One of the easiest ways possible to convert a bike and keep it street legal

Specifications

Wattage: 250watt-350watt depending on number of batteries installed
Battery included: Yes
Motor position: Friction connection to rear wheel

Reasons to buy

+
Easy to install
+
Easy to remove for charging or anti-theft
+
Lightweight

Reasons to avoid

-
Not an ideal pairing with mountain bike tires

Rubbee X might not be the best option to shred single track but if you are looking to convert a mountain bike to commuter duty it's an excellent option. Stick with one or two batteries and you can stay street legal in Europe or add a third battery for a bit more range, and speed, in the US. The battery and motor are a single unit that clamps to the seat post and pushes against the rear tire. Knobby mountain bike tires will make a bit more noise but as long as it’s less than 2.5 inches wide they will work just fine with this system. 

Electric conversion kits for mountain bikes: Everything need to know

The most important thing you need to do when considering an electric bike conversion is to check the laws and regulations where you are. It's much easier to go afoul of what's allowed when buying a kit. A lot of the time if you buy a bike the manufacturer has been through the process of ensuring what you are buying is okay in your location. There are different options available in different parts of the world. Buying a kit puts a lot more of the responsibility on your shoulders. 

The laws governing electric bikes are hyper-local. They change depending on what country you are in but, for example, in the US different states have different laws and it can even get more local than that. Check the size of the motor, does it have a throttle, what is the max assisted speed, as they all change the requirements. 

Depending on the system you end up with there are different requirements. Some systems will make trails off-limits. Other systems might be okay but require insurance. Make sure you have an understanding of what you are getting and what that means for riding it in your location.  

Do I need a battery?

There's not a huge explanation needed for this. You need a battery; make sure the kit you select has it. Not all kits include it. If you find yourself browsing through options and landing on something at an unbelievable price, look for the battery. You can source the battery yourself but be sure about what you are getting.

What are the different types of conversion kits?

Friction Drive Conversion: This type of system doesn’t really work with anything other than slick tires. There’s none in this list for that reason but you can still get a sense of what they are. If you’ve got a mountain bike you use for commuting duties you could change tires and make one of these systems work. A roller pushes against the tire 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.

Should I buy an electric mountain bike instead?

When it comes to electric bikes the price is in the motor and especially the battery. Frames and components benefit greatly from economies of scale. Large manufacturers place huge orders and get great deals on all the pieces. That means if you are converting a bike, you already own, you are purchasing the expensive pieces for the conversion. In turn, that means you might not get much of a deal on an electric bike conversion. 

If you are considering converting a bike you own to electric power only for cost savings, think hard about it. In most cases, it's just not going to be worth it. Not only that but a great conversion kit on a not great bike isn't going to be a lot of fun. There are some inexpensive electric bikes out there that are excellent to ride so if the price is the driving factor that's a better option.

That doesn't mean you shouldn't convert a bike you own. If you have a good bike you love then consider a conversion. Finding a new bike can be a challenge and sticking with what works has advantages. Just know, it might not be a cost-saving.

Josh Ross is our American tech writer. Born and raised in the Pacific Northwest of the United States he lives cycling and the culture that accompanies it. Josh is most happy when talking about the finer details of how bicycle parts and components work, and enjoys putting his thoughts to words for Bike Perfect. He is a road cyclist at heart but can often be found taking the gravel road less travelled. Although he rarely races these days, he still enjoys a good Zwift session and race but will always choose the real world over pixels when given the choice.
Height: 5'9"
Weight: 137 lb.
Rides: Look 795 Blade RS, Cannondale Topstone Lefty, Cannondale CAAD9, Priority Continuum Onyx