Adding an engine to a pedal bike transforms it into a motorized bicycle, offering a boost for commuting or recreation. We researched and compared seven top engine kits based on manufacturer specifications, published standards, and aggregated owner feedback. Our evaluation focuses on real-world performance, durability, ease of installation, and safety. Here are the best options, with honest assessments of their limitations and who should skip each pick.
| Photo | Product | Score | Buy |
|---|---|---|---|
 |
Bafang BBS02B 750W Mid-Drive Kit Best Overall 750W mid-drive motor, 48V battery, top speed 28 mph |
9.0 | 🛒 Check Price |
 |
Voilamart 26 inch 48V 1000W Rear Hub Motor Kit Best Value 1000W rear hub motor, 48V battery, top speed 30 mph |
8.7 | 🛒 Check Price |
 |
SWAGTRON EB5 Pro Electric Bike Conversion Kit Best for Commuting 350W front hub motor, 36V battery, top speed 20 mph |
8.4 | 🛒 Check Price |
 |
E-BikeKit 500W Rear Hub Motor Conversion Kit Premium Pick 500W rear hub motor, 48V battery, top speed 25 mph |
8.1 | 🛒 Check Price |
 |
CYC Motor X1 Pro Gen 2 Mid-Drive Kit High Performance 3000W peak mid-drive motor, 72V battery, top speed 45+ mph |
7.8 | 🛒 Check Price |
 |
Aosom 2-Stroke Gas Engine Kit 80cc Budget Gas Option 80cc 2-stroke engine, top speed 25 mph, single cylinder |
7.3 | 🛒 Check Price |
 |
Bafang G310 250W Front Hub Motor Kit Lightweight Option 250W front hub motor, 36V battery, top speed 15 mph |
7.2 | 🛒 Check Price |
1. Bafang BBS02B 750W Mid-Drive Kit: Best Overall
The Bafang BBS02B is a popular mid-drive conversion kit that replaces the bike’s bottom bracket, providing power directly to the chain. In our research, owner feedback highlights its smooth power delivery and ability to tackle steep grades without overheating. The 750W motor offers a good balance of speed and range, and the programmable controller allows customization of pedal assist levels. However, installation is not straightforward: it requires specific tools and mechanical knowledge, and compatibility with some frames is limited.
This kit is best for experienced DIYers who want high performance and are willing to invest time in installation. Those looking for a simple bolt-on solution or who have unusual frame geometry should consider a hub motor kit instead. Based on owner feedback, the BBS02B is a durable choice, but the battery and display are separate purchases, adding to the overall investment.
- Mid-drive design for natural ride feel and hill climbing
- Programmable controller for tuning power delivery
- Includes display, throttle, and pedal assist sensor
Pros: Excellent torque for steep hills; Reliable and widely supported
Cons: Complex installation requires bottom bracket tool
2. Voilamart 26 inch 48V 1000W Rear Hub Motor Kit: Best Value
The Voilamart 1000W rear hub motor kit is a complete package that includes a pre-laced wheel, making installation relatively simple. Owner feedback often praises its straightforward setup: you just replace the rear wheel and mount the battery and controller. The 1000W motor provides strong acceleration on flat roads and can handle moderate hills, but it struggles on very steep inclines. The kit’s value is high, offering a lot of power for the price.
However, the added weight on the rear wheel can make the bike feel unbalanced, especially when cornering. Additionally, the controller is not programmable, so you are limited to the default settings. This kit is ideal for budget-conscious riders who prioritize ease of installation and flat terrain performance. Riders with hilly routes or who want fine-tuned control should look at mid-drive options.
- Complete kit with wheel, controller, throttle, and display
- Simple installation, no bottom bracket removal
- High power for flat terrain and moderate hills
Pros: Great value for the power output; Easy to install on most standard frames
Cons: Rear hub motor adds weight and affects handling
3. SWAGTRON EB5 Pro Electric Bike Conversion Kit: Best for Commuting
The SWAGTRON EB5 Pro is a front hub conversion kit designed for simplicity and daily commuting. In our evaluation, it stands out for its ease of installation: the motor is integrated into a lightweight front wheel, and the battery mounts on the handlebars. Owner feedback indicates that the 350W motor provides a gentle boost, making it suitable for flat to gently rolling terrain. The battery range is adequate for short to medium commutes, and the pedal assist feels natural.
However, the low power means it is not suitable for steep hills or riders over 200 lbs. The front hub motor can also cause wheel slip on loose surfaces. This kit is best for casual commuters who want a simple, low-maintenance conversion and do not need high speeds or hill-climbing ability. Enthusiasts seeking performance should consider higher-power options.
- Compact front hub motor, low profile
- Includes battery, charger, and display
- Pedal assist and throttle modes
Pros: Very easy to install, no special tools; Lightweight, does not significantly alter bike balance
Cons: Limited power for steep hills or heavy riders
4. E-BikeKit 500W Rear Hub Motor Conversion Kit: Premium Pick
E-BikeKit offers a 500W rear hub motor kit that emphasizes quality and support. Our research shows that the motor is well-built, with sealed bearings and a durable controller. The kit includes a torque arm to prevent axle spin, a safety feature often missing in cheaper kits. Owner feedback highlights the reliability and the company’s responsive customer service. The 500W motor provides a balanced performance for commuting and recreational riding.
The main drawback is the price: it costs more than many comparable 500W kits from lesser-known brands. Additionally, the standard controller is not programmable, though an upgrade is available. This kit is best for riders who prioritize durability and support over initial cost. Budget-conscious buyers may find better value elsewhere.
- High-quality components with known brand reputation
- Includes torque arm for safety
- Programmable controller available as upgrade
Pros: Durable motor and controller; Good customer support from a US-based company
Cons: Higher price compared to similar power kits
5. CYC Motor X1 Pro Gen 2 Mid-Drive Kit: High Performance
The CYC X1 Pro Gen 2 is a high-performance mid-drive kit designed for enthusiasts and off-road use. In our evaluation, its 3000W peak power is impressive, capable of propelling a bike to over 45 mph. The motor is compact but delivers massive torque. The programmable controller allows fine-tuning via a smartphone app, which is a standout feature. However, this power comes at a cost: the kit is very expensive, and it demands a strong bike frame and high-quality components to handle the stress.
Installation is complex and not for beginners. The kit also puts significant strain on the drivetrain, leading to faster wear of chains and cassettes. This product is best for experienced riders who want extreme performance and are willing to invest in a strong build. It is not suitable for casual commuters or those on a budget.
- Extremely high power for off-road or speed
- Advanced programmable controller with phone app
- Solid chain and sprocket design
Pros: Unmatched power and acceleration; Customizable performance via app
Cons: Very expensive and requires high-end bike frame
6. Aosom 2-Stroke Gas Engine Kit 80cc: Budget Gas Option
The Aosom 80cc gas engine kit offers a traditional motorized bicycle experience. It is a 2-stroke engine that mounts on the bike frame and drives the rear wheel via a chain. Owner feedback highlights the low cost and the ability to travel long distances without worrying about battery range. The installation is moderately challenging, requiring mechanical skills to align the engine and chain. Once running, it provides a decent top speed of around 25 mph.
However, the engine is noisy and emits smoke, which may not be suitable for all environments. Reliability can be spotty; some owners report issues with carburetion and vibration. This kit is best for hobbyists who enjoy tinkering and want a low-cost gas option. Those who prefer quiet, clean operation should choose an electric kit.
- Gas-powered, no battery charging needed
- Complete kit with engine, mount, chain, and exhaust
- Low initial cost compared to electric kits
Pros: Long range with a tank of gas; Simple mechanical design
Cons: Loud and produces exhaust fumes
7. Bafang G310 250W Front Hub Motor Kit: Lightweight Option
The Bafang G310 is a lightweight front hub motor kit designed for riders who want a subtle boost. It features a torque sensor that provides natural-feeling pedal assist, and the motor is almost silent. In our evaluation, the 250W motor is best for flat urban environments where you need a little help against headwinds or to maintain speed. The kit is easy to install and does not significantly change the bike’s handling. Regenerative braking is a nice addition, but its effect on range is minimal.
The main limitation is power. This kit is not suitable for hills, and the top speed is limited to 15 mph. It is also relatively expensive for the power output. This kit is best for casual riders who want a lightweight, low-profile electric assist for flat commutes. Performance-oriented riders will be disappointed.
- Ultra-lightweight, adds minimal weight to bike
- Smooth pedal assist with torque sensor
- Regenerative braking capability
Pros: Very quiet and efficient; Ideal for flat terrain and light assistance
Cons: Low power, not suitable for hills or heavy loads
Frequently Asked Questions
Is it legal to put an engine on a pedal bike?
Laws vary by location. In many areas, motorized bicycles are classified as mopeds or electric bikes with restrictions on power (e.g., 750W for e-bikes) and speed (typically 20-28 mph). Gas engines may require registration, insurance, and a license. Always check local regulations before purchasing and installing a kit.
Which is better: mid-drive or hub motor?
Mid-drive motors offer better hill climbing and balanced weight distribution but are more complex to install and maintain. Hub motors are simpler and cheaper but can add weight to the wheel and affect handling. Your choice depends on terrain, budget, and mechanical skill.
How long does a battery last on an electric bike conversion?
Battery range depends on capacity (Ah), rider weight, terrain, and assist level. Typical 48V 13Ah batteries provide 20-40 miles per charge. Higher capacity batteries extend range but add weight. Always consider your commute distance and charging options.
Can I install a motor kit on any bicycle?
Most kits fit standard frames, but compatibility issues exist. For hub motors, you need proper dropout width and a sturdy frame. Mid-drive kits require a compatible bottom bracket (e.g., BSA standard). Disk brake mounts may also be needed. Check specifications before buying.
Do I need special tools to install a motor kit?
Hub motor kits typically require basic tools like wrenches and screwdrivers. Mid-drive kits need bottom bracket tools and possibly a crank puller. Gas kits require engine mounting hardware. Some kits include necessary tools, but many do not. Plan ahead.
Our Verdict
After thorough research and comparison, the Bafang BBS02B 750W Mid-Drive Kit earns our top pick for its balance of performance, durability, and versatility. It excels on hills and offers programmability for a customized ride. For those seeking a simpler, more affordable option, the Voilamart 1000W Rear Hub Motor Kit delivers excellent value and easy installation, making it a strong runner-up.
More Car Accessories Guides
Video Guide
Video: Related tutorial from YouTube