10 Best Bicycle Engine Kits 2025 in the United States

The CUBELLIN Upgraded 100cc Bicycle Engine Kit is designed to transform a regular 26"-28" bicycle into a motorized bike with a 2-stroke 100cc engine. It’s powered by gasoline and offers a top speed of around 48 km/h, making it a practical choice for those wanting to add extra speed without buying a full motorcycle. One of its standout features is its fuel efficiency—running about 150 miles per gallon, which helps keep running costs low.

Installation requires some mechanical skill, but the kit includes all necessary parts and a manual to guide through the process. The engine mounts use 8mm bolts instead of the common 6mm, providing stronger and safer attachment to the bike frame. The engine body is made of aluminum and iron components treated to resist wear, promising decent durability if maintained properly. However, as a 2-stroke motor, it will need regular maintenance like oil mixing and carburetor tuning for best performance. The kit comes with an upgraded carburetor that has adjustable settings, allowing better control over fuel delivery and easier starting in cold weather—an advantage for varied climates. It supports a maximum load of about 200kg (440 lbs), suitable for most adult riders with some cargo. This kit is especially good for users with limited budgets or those who want motorized assistance only occasionally or for short trips.

On the downside, the rigid suspension and absence of included brakes mean your existing bike setup must handle those safety aspects. Also, it may not fit all bike frames perfectly, so checking compatibility beforehand is important. While the speed and power are good for casual use, it’s not designed for heavy-duty or long-distance riding. This engine kit provides a cost-effective, fuel-efficient way to motorize a suitable bike with moderate speed and solid build quality, making it best suited for hobbyists or practical users looking for an easy upgrade rather than a full motorcycle replacement.

This 100cc 4-stroke gasoline bicycle engine kit offers solid power with 3.5 horsepower, allowing speeds up to around 50 km/h, which makes it a good choice for riders wanting a noticeable boost without going full motorcycle. Its air-cooled OHV (overhead valve) engine design helps reduce fuel consumption and carbon buildup, making it more economical and reliable over time. The kit includes a large 0.52-gallon fuel tank, so you won't need to refuel frequently during rides. Durability is a strong point here, thanks to corrosion-resistant materials like aluminum and steel, plus a robust chain and belt system designed to handle up to 440 pounds, suitable for heavier frames.

Noise levels are moderate, about 75dB, so it won’t be completely silent but should be acceptable for outdoor use. Installation might require some mechanical skill since it’s intended for large triangular bicycle frames or motorized bike modifications, and compatibility depends on your bike’s frame size and setup. This makes it a great budget-friendly option for those wanting to convert a bicycle into a motorized bike without investing in a full motorcycle.

It may not be the best fit if you need a simpler plug-and-play system or if your bike frame is smaller or uniquely shaped. Also, while maintenance is relatively straightforward due to the 4-stroke engine design, some familiarity with engine upkeep will be helpful to keep it running smoothly.

The 100CC Bicycle Engine Kit is designed to convert a traditional bicycle into a motorized one, making it a good option for those who want to enhance their biking experience. The engine is a 4-stroke, air-cooled unit that offers a more stable and quieter ride compared to 2-stroke engines. With a speed capability of 3600 RPM and a horsepower of 3 HP, this engine provides decent performance for commutes and short journeys.

The use of aluminum alloy for the engine body adds to its durability and longevity, while the plastic housing ensures protection from external damage. One notable feature is the complete engine kit, including all necessary hardware for installation, which simplifies the conversion process and saves additional costs on accessories. However, the installation complexity could be a bit challenging for those without mechanical experience, as it involves fitting and adjustments to the bike. The compatibility is generally good for beach bikes with large triangular frames, but users should verify their bike's structure to ensure a proper fit.

With a fuel tank capacity of 54 fl oz, the engine allows for extended use on a single fill-up, making it economical in terms of fuel consumption. On the downside, the kit is relatively heavy at 44 pounds, which could affect the bike's handling and ease of use. In summary, this engine kit is suitable for enthusiasts looking to upgrade their bicycles for better speed and efficiency, provided they are ready to tackle the installation process and handle the additional weight.