One of the most exciting and cost-effective projects you can take on is converting your conventional bicycle into a powerhouse electric bike. A rear wheel best e-bike conversion kit is usually the way to go because it has good traction and handling and maintains some of the authentic bike riding experience. But with so many rear wheel e-bike conversion kits available, deciding on the right one may be challenging. This brief guide will aid you in selecting the right e-bike conversion kit by applying the five most important dimensions.
First and most critical dimension: Core Performance and Mechanical Compatibility
This is the basis of your e-bike conversion; everything else you choose has to be compatible with this. Getting this wrong means the kit will not fit the bike as expected or will perform incorrectly. You must match the specifications of the kit to your bicycle’s frame and what kind of performance you expect from your e-bike. Measure your bike carefully first; this part comes before choosing a brand or battery. This will prevent wasting money on something that does not fit and getting frustrated with an unwieldy installation. Focus on the core hardware first.
Motor wattage and voltage
These two combined determine the amount of power and speed your e-bike can offer. For a commuter or general use, 250W-500W is more than sufficient, and the lower wattage will save you battery life and weight. If you are looking for higher speed or intend to drive up steep hills, a 750W or even 1000W motor will provide high torque and assistance. Voltage works with wattage; a 48V system will generally feel more “punchy” and provide more assistance and climb power than a 36V system with the same wattage.
Dropout Spacing
This is by far the most important measurement to make. It is the distance between the inner faces of the frame where the axle of the wheel is fastened. You must get this one right by actually measuring it with a ruler or calipers; most modern bikes have the same rear dropout spacing, but you need to confirm this. A 135mm dropout kit will not fit a 142mm frame without modification. A kit designed for the following spacings will fit the following types of bicycles:
| Dropout Spacing | Compatible Bicycle Types |
|---|---|
| 130mm | Older road bikes |
| 135mm | Mountain bikes, hybrids, and cruisers |
| 170mm-190mm+ | Fat Tire Bike |
Wheel Size
Kits are designed for specific wheel sizes, such as 26", 27.5", 700c, and 29". It’s all too easy to order the wrong size. Check the sidewall of your existing tire to get your exact wheel size before purchasing.
Brake Compatibility
Check that the hub motor is compatible with your bike’s braking system. Most modern kits are intended for disc brakes, which are frequently a 6-bolt pattern, but some kits may work with older rim brakes or come with an adapter.
Battery System and Realistic Range
Finally, you need to assess the Battery System and Realistic Range. One of the most crucial components of a powerful motor is the power source. The battery, the most expensive part of a conversion kit, has specifications to understand whether it is of value and if it is capable of satisfying your daily biking requirements. Do not trust the maximum claims; instead, learn to determine the battery’s true capacity for your usage. It can be assessed in the following aspects:
Battery Capacity (Amp Hours – Ah)
This is the battery’s fuel tank; measure it. The higher the Ah, the longer the range you can travel on a full charge. For instance, a 10Ah battery is suitable if you plan only short commutes. However, if you consider long-distance touring or heavy throttle, opt for the 15Ah or 20Ah+.
Watt-Hours (Wh) Calculation for True Comparison
A proper way to measure range is by calculating the Wh. You simply multiply the voltage by the Ah to find the Wh. For instance, a 48V 15Ah battery (720Wh) offers a far longer ride than a 36V 20Ah that delivers 720Wh, but they are similar. Therefore, the Wh should be your most used measure when comparing the energy storage capacity.
Battery Mount Style
There are a couple of styles kits typically offer. The downtube, also known as a shark battery, mounts to the bottle cage bosses on your frame with excellent weight distribution and a clean appearance. A rear rack battery works with a rack and sits on the rack just over the rear wheel. Some frames make it easier to install but may make your bike feel more top-heavy.
Charger Quality
Kits should have a smart charger; else, there is a chance of over-charge. Pick one with an output of 2A to 4A. Higher will mean a quick fill, but a 2A will be kinder to the battery over the longer duration.
Control System and User Interface
The third dimension is the Control System and User Interface, which dictate your whole riding experience. Whether you activate the motor, maintain your speed, and regulate assistance levels determine how much you will enjoy your freshly transformed electric bicycle. A clunky or unnatural system will be irritating, while a smooth and responsive one will be fun to use. Kits that offer kit sensors and displays should be studied closely.
Throttle vs. Pedal Assist System
Most kits contain the two. A throttle, thumb or twist-grip type, allows you to power on command without pedaling. A pedal-assist system engages independently when you pedal.
Pedal Assist Sensor Type
This is a significant factor. The most widely used and affordable type is a Cadence Sensor. The sensor identifies that you are pedaling and powers a predetermined level depending on that assist level. On the other hand, a Torque Sensor measures how hard you pedal and proportionally drives a variable power level. As a result, the ride is more natural and normal, almost as if your legs have been energized.
Display Unit
The dashboard is the name given to it. The basic LED display will show you the battery level and the assistance level. The more comprehensive LCD monitor shows a volume of details, including speed, distance traveled, odometer, watts of output, and frequently, monitor error codes. A backlit LCD screen that is readable is a worthwhile investment.
Wiring and Connectors
You should look for kits with waterproof, color-coded connectors.
Installation Process and Kit Completeness
A conversion kit should be a DIY-friendly project. The best kits are those that are made for easy assembly – often with common bicycle tools. A complete kit will save you the headache and hidden costs of having to source missing parts halfway through your build. Always verify exactly what is included in the box beforehand. A truly comprehensive kit will contain the motorized wheel, the battery and charger, the controller, the display unit, the throttle, the pedal-assist sensor, both brake levers with motor cut-off switches, and all necessary wiring.
Be aware that some kits do not include tools. While it is common for kits to include a few small tools, you will need your own set of Allen keys, a pedal wrench, a crank puller, a cassette/freewheel removal tool, and tire levers. Specifying the tools needed to complete the kit in advance eliminates potential delays. Vague instructions are also a major setback. Look for reviews or product descriptions that mention clear, comprehensive instructions, or better yet, video tutorials. A great project can go horribly wrong if you try to follow unclear or badly translated instructions. Good customer support from the seller is a huge bonus. While it may seem cheaper to buy components separately, a full kit from a single manufacturer is almost always the better value. The components are guaranteed to be compatible with each other, and the overall price is typically lower vs. individually sourcing each part.
Reputable Source and High-Quality Components
The durability and dependability of your e-bike in the long run mainly depend on the quality of the suited components and the level of support you will receive from the brand that makes it in case of an issue. Most of the parts used in e-bike conversions can be found from generic kits, but using a source with a proven track record, be it a motorbike brand, is likely to provide superior performance, safety, and peace of mind. When looking into where to invest in your parts, it is important to pick a brand that excels. For example, ENGWE is known not only for their well-crafted full electric bikes but also their top-tier quality and innovation. Their market impact stems from their high-quality individual parts that make up a superior e-bike just like you are assembling. Acquiring your replacement parts from them ensures that you have parts that have been manufactured to the same high standards as their well-known factory models.
ENGWE Accessories: Upgrade
Official ENGWE Accessories: Click here to find a rich variety of accessories.
Buy NowThis is a collection of high-performing accessories for riders looking to upgrade or establish a system with high-performing components. The ACCESSORIES store features vigorous, high-capacity batteries that can propel you as needed, robust controllers that smoothen power output, and clear, precise LCD displays. Investing in genuine products implies you are building with components created to last and provide over-class satisfaction.
Official ENGWE Accessories: Follow the link to find a variety of accessories.
By acquiring parts from a reputable firm like ENGWE, you can confirm that your entire conversion will be of high quality and will utilize known components from a respected firm in the e-bike industry.
Other Notable Kit Brands
Other well-known and dependable brand manufacturers of either of the generic components centralized kits worth investigating include Bafang, a popular hub and mid-drive motor manufacturer, and Swytch, known for their simplistic, inexpensive front-wheel conversion kits.
Warranty and Support
Confirm the warranty lifespan for the motor and battery. It is important to purchase from a well-intentioned retailer that believes in its product, and the best ones provide a warranty of at least one year and have a simple method you can follow when you face challenges in the assembly process or complaints about the delivered product.
What is the most important measure of compatibility one should be checking before buying?
The first and most critical measure is rear dropout spacing. If the motor’s axle width does not match your frame rear dropout spacing, the motor will not fit, end of story. Now you have the very first and must measure out of the way! Easy!
1) Is a 750W motor always better?
The answer is no. While a more power-hungry 750W motor is excellent for steep hills or high top speeds, it will only make battery life worse. It also may not be road legal in some areas. Finding a 500W motor is the perfect middle ground for most commuters, but 250W may be enough if you live in a flat area.
2) Can I use the gear cassette I got on the new motor hub?
Yes, you can generally transfer your existing cassette from your wheel into your new hub motor’s freehub body in the case of the rear wheel installation of the kit. Search the internet for your cassette’s removal technique and acquire a tool for disassembly while performing your installation. The right rear wheel kit will transform your commuting experience forever, and you will thank yourself.
