The 6 Best E-Bike Conversion Kits

Here's how to add some oomph to your favorite two-wheeler.

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Collage of e-bike conversion kits we recommend on a green background

Treehugger / Lecia Landis

E-bikes are easier on the environment than cars. They’re also easier to pedal than a standard person-powered two-wheeler. You get as much exercise riding an e-bike as you do a traditional bike. Thanks to improved technology and more people interested in alternative transit methods, e-bikes are also becoming more available—and more affordable.

But no electric bike is as cheap (or as green) as the bike you already own. If you’re trying to reduce your carbon footprint, living in a small space, or practicing minimalism, using what you have on hand can be a win-win decision. So, if you love your current ride but want to add some juice for getting uphill or powering your cargo bike when carrying a heavy load, you can, thanks to electric bike converter kits. You will need a battery, sensors, controls, and a motorized wheel or a drive unit to electrify your bike—kits contain most or all of these components.

Here are the best options for upgrading your bike with an e-bike conversion kit.

Since 2003, Bafang has been a leader in manufacturing e-mobility components and complete e-drive systems. Its products offer outstanding performance and reliability, and the BBS02B conversion kit is no exception, making it our top overall choice.

This mid-drive motor kit is versatile and compatible with road, commuter, and mountain bicycles. All you need is a bike with a 68-73 millimeter bottom bracket and the battery of your choice. Installation is relatively easy, and the battery is included. Once the kit is installed, you’ll be ready to tackle any hill.

Although several different conversion kits are available online from Bafang, those with more than 750 watts of power will be considered motorcycles in the United States.

This front-wheel E-bike conversion kit is easy to set up and easy on your wallet. Electrify your bike in one hour by following the installation video and manual. Don’t forget to choose the correct wheel size!

After setup is complete, ride around the town with pedal assist or switch to e-bike mode for longer trips. Commuters, long-distance trekkers, and mountain bikers can cruise up to 24 miles per hour. The battery is not included.

Daily riders will love this easy-to-install, lightweight e-bike conversion kit. It is compatible with most mountain, road, hybrid, and step-through bikes, and disc brakes.

It’s as easy to install as swapping out your front tire. The controller and battery are combined into a 34.2-Volt power pack, which is included in the kit and mounts to the handlebars. That makes it easy to remove and keeps thieves at bay, but our tester did miss having the use of a handle bar basket. The battery pack is fitted with indicator lights that tell you how much juice remains and what assist mode you’re in. Once the system is set up correctly, you’ll be able to top out at 15-25 mph.

What Testers Say

"In general, I love it. It makes my ride easier without feeling like I’m riding a giant bulky e-bike. It’s got a phenomenal amount of power for such a little machine and seems like it has a good battery life too." ~ Treehugger Tester

Do you want to go farther or faster? You can do both with this setup from Ebikeling, with its 500-watt motor. Ebikeling makes it easy to buy different compatible batteries and other accessories in an à la carte way. There are seven different batteries that come in different shapes (bottle, triangle, rectangular) so that you can pick the one that suits your bike and needs best.

The double-walled rim and motor are ready to install right out of the box—just swap them out for your original bike tire. An LCD screen is included to help you stay within your town’s speed limit. You can choose between a front or rear mount and a thumb or half-twist throttle.

Thanks to a 48-volt, 1000-watt battery, the AW wheel E-bike conversion kit satisfies anyone with the need for speed. A thumb throttle makes speed control simple. This kit is available as either a front-wheel or back-wheel conversion option. It fits any 26-inch bike frame with a 3.9-inch front dropout spacing (for a front wheel conversion) or 5.3-inch rear dropout spacing (for a back wheel conversion). The rear wheel kit weighs 24.7 pounds; the front wheel kit weighs 23.5 pounds.

The aluminum frame offers durability and stability, essential when rolling at top speeds of 28 miles per hour. Hand brakes turn the motor off automatically to both improve safety and conserve battery power.

Easiest to Install

Rubbee X Conversion Kit

Rubbee X Conversion Kit

Rubbee

If you want the fastest conversion possible and even the option to take a motor off your bike quickly, the Rubbee X makes it a snap. The Rubbee X gives you a boost by resting against the rear tire and has a special release that lets you remove the motor without un-mounting the entire system. You control the power just by pedaling, as a wireless cadence sensor that gets mounted to the pedal crank sends information to the motor, which shifts automatically without any additional user interface. 

This conversion kit has some other nice features. It has tail lights on the back of the motor to give you some additional visibility when riding at night. The base model comes with one battery, which weighs 6.1 pounds, gives you 250 watts of power, and has a top speed of 16 mph. Upgraded models have two or three additional batteries, each offering more speed and power but also adding more weight. It’s compatible with any frame type and with tires that are between 0.5 and 2.5 inches in width and between 16 and 29 inches in diameter. 

There are a few things to keep in mind before you buy. First, the product ships from the European Union, so an additional import tax may exist. Second, you’ll want to make sure you have plenty of room on your seat post to connect the motor.

Final Verdict

Whenever you’re buying a newer technology, sticking with a known brand makes sense. That makes Bafang’s E-bike conversion kits a sound choice—in terms of quality and price. If speed is what you’re after, the kits from Ebikeling.

What to Consider When Shopping for an E-Bike Conversion Kit

Battery

Is the battery included? You’ll need something to power and charge your e-bike conversion kit. Many kits include a battery. Cheaper kits may not, though, which means you’ll need to source a compatible battery separately.

Power

You'll also want to think about your power needs. The higher the motor wattage, the more power you'll get. A 250-watt motor is typically plenty of power to make the daily commute less sweaty. If you want to take your converted bike out on tougher mountain trails, you'll want more power.

Keep in mind that according to U.S. federal regulations, e-bikes with more than 750 watts of power are considered motor vehicles and require a motorcycle license.

Local Laws

You’ll want to check your state and local laws as some cities and towns have banned e-bikes from bicycle paths, so if that’s where you want to ride, you’ll want to make sure your town allows your upgraded bike to cruise around on them.

E-bikes come in three classes:

  1. Class 1 E-bikes that assist you while you pedal and top out about 20 mph.
  2. Class 2 E-bikes have a throttle that assists you regardless of whether you pedal and have a top speed of 20 mph.
  3. Class 3 E-bikes assist you while you pedal and top out about 28 mph.

Drive Type and Installation

There are several kinds of e-bike conversion kits, and the ease of set-up and installation varies.

  • Friction Drive Conversion is a simple strategy. A roller pushes against the tire on the wheel. When the roller turns, the wheel turns. It’s a reasonably easy system to set up but sometimes isn’t the most effective.
  • Mid-Drive Conversion is the technology that the best e-bikes tend to use. A weight sits at a low point on the bike frame, and the power is applied to the crank. These can be more expensive, but the technology is typically better. There’s no standardization, however, which can make figuring out exactly what you need to make your bike work a little more challenging. Adding the parts is also a bit more complex than friction drive conversion.
  • Electric Bike Wheel Conversion swaps out a non-electrified front or rear wheel with an electrified one. The process is simple depending on where and how the battery mounts—such as on a rear rack. Once installed, weight distribution can feel natural. However, powering the front wheel may impact your bike’s handling.
Frequently Asked Questions
  • Are electric bike conversion kits difficult to install?

    The difficulty of installation depends of the type of conversion kit, as well as your comfort with the tools required. But generally speaking, converting your bike is a DIY project. Many manufacturers offer how-to videos that show what’s involved, so you can see ahead of time what you’ll need to do. 

  • What tools do I need?

    You’ll need a bike tool, crank arm tool, adjustable wrenches, and a screwdriver along with your electric bike conversion kit.

    These demos can show you how to install your e-bike conversion kit.

  • Should I get a conversion kit or just buy a new e-bike?

    A visit to your local bike shop mechanic is a helpful step in the decision-making process. They can help you determine if your bike is a good candidate for electric technology.

    Your old bike may not be able to be converted because adding a motor can increase torque. You’ll want to make sure your bike’s drivetrain can handle it.

    The extra weight from adding an electric motor also impacts your brakes, so you’ll want to make sure they are effective for stopping at a higher speed. E-bikes tend to have disk brakes for this reason. If your current bike is in disrepair, has old parts, or needs other improvements, it may be more cost-effective to sell your trusty old ten speed and buy an e-bike.

    Also, consider that a quality electric bike conversion kit can be nearly the cost of an electric bike. Do some comparison shopping between the price of a conversion kit and a fully-loaded e-bike before you decide which way you want to roll. Our picks for the best e-bikes may help guide your decision.

Why Trust Treehugger?

Treehugger has reported on dozens of e-bikes and e-bike conversion options over the past decade. To make this list, we deeply researched the market by reading other third-party reviews, user comments, and enthusiasts blogs. We also considered the product’s value and the manufacturer’s reputation.

Author Heidi Wachter has been writing about travel and adventure for over a decade. When she’s not writing, you’ll likely find her riding one of her six bicycles—even in the winter.

View Article Sources
  1. Philips, Ian, et al. "E-Bike Carbon Savings - How Much and Where?" Centre for Research into Energy Demand Solutions.

  2. Castro, Alberto, et al. "Physical Activity of Electric Bicycle Uses Compared to Conventional Bicycle Users and Non-Cyclists: Insights Based on Health and Transport Data From an Online Survey in Seven European Cities." Transportation Research Interdisciplinary Perspectives, vol. 1, 2019, pp. 100017., doi:10.1016/j.trip.2019.100017