With most every single conversion kit being made for either 26-inch or 700c rims, people riding small wheels (about 20 inches) are forced to make their own solutions. The YIYIBYUS 20 inch rear hub conversion kit provides an alternative by offering a complete solution that includes the necessary components for converting your 20-inch bike into a fully functional ebike.
The cost of the conversion kit is less expensive than many other kits available today, leaving room in your budget for purchasing an appropriate ebike battery, which is probably the best place to spend money when building an ebike. If you currently ride a 20-inch commuting bike, or perhaps a folder, then this may be an ideal option for you.
Please refer to our conversion walkthroughs section for basic information on how to assemble these types of conversion kits.
Specifications & Quality of Components
This conversion kit uses a 48V 1000W brushless gearless rear hub motor. "Gearless" means the motor operates directly connected to the rear wheel. Therefore there are no internal planetary gears inside the motor. This means some loss of low-speed torque, however it also produces quieter operation and improved heat dissipation during long steep climbs. Additionally, since there are fewer mechanical components in the motor itself, there are fewer things that can fail. In terms of overall durability of the motor, the benefits of using a gearless design far outweigh any potential drawbacks in regards to increased weight of the motor.
For example, here is a link to a direct-drive primer on ebikes.ca that goes into detail regarding the advantages/disadvantages of using a direct-drive vs geared motor design.
The maximum speed achieved by this conversion kit is approximately 31 mph (50 km/h), based on the manufacturer's specifications. On smaller diameter tires such as those typically found on 20-inch ebikes, 31 mph is sufficient speed for most users. The system is rated for use at a 48V nominal voltage and comes pre-installed onto a rim, therefore all you need to do is simply drop it into your bike and tighten it down. All other items included in the kit are:
- a 5-magnet pedal assist sensor
- an electric brake lever with motor cut off switch
- a thumb throttle
- an SW810 LED display unit with speedometer functionality (displaying current speed, battery charge level, and assist level)
The LED display unit is relatively small and unobtrusive on your handlebars.
Note: One item not included in the kit is a tire. Everything else including the motor wheel, controller, throttle, brake lever, and sensor come with the kit. So, please ensure you have a suitable tire and tube for a 20-inch ebike installed prior to taking your bike for a spin!
Installation & Compatibility
As this replacement hub converts your rear wheel, installation involves simply removing your original rear wheel and installing this hub in its place. Then, connect the electrical cables and attach the display and throttle. The motor is designed for 135mm wide dropouts, so if your frame is 135mm wide it will fit. If not, you will require additional hardware or a different kit.
In addition to fitting your frame size, compatibility extends to braking systems. Specifically, the kit supports V-brake systems and disc brake systems as long as the pad or caliper lines up with the rim or rotor after assembly. No brake swap required!
Lastly, in terms of electrical connectivity, phase wire matching and Hall sensor wire matching are critical. Connect them incorrectly and your motor will run roughly or refuse to engage altogether. Simply double-check the colors to correct them.
What Buyers Are Saying About This Product
There are only two buyer reviews for this listing, and both buyers gave it five stars. While the sample size is small, this is an optimistic beginning.
Oleg Shpungin noted his motor worked well and was smooth operating. He did note he thought he would receive a larger wheel and eventually had to adapt tires to work with his actual 20-inch wheel. Lesson learned: read the listing carefully. This conversion kit is intended solely for 20-inch wheels and will not work properly on anything larger than this! If you ride a 26-inch or 700c wheel, this is the wrong kit. Please see our conversion kit guide for options on other wheel sizes.
Who Should Buy This Conversion Kit?
Anyone who owns a 20-inch bike, whether it be a folder or compact commuter bike. Anyone who wants electric functionality on their bike without spending a fortune on their conversion kit. Any cyclist who values low maintenance and quiet operation with their direct-drive motor and isn't concerned about the added weight. If any of these descriptions apply to you, this conversion kit was designed specifically for your bike. Before committing to purchase the conversion kit, please view the current price on Amazon.
FAQs
Do I Need Tires Too?
No! The kit contains the motor wheel, controller, display unit, throttle, brake lever, and sensors. You will need to provide your own 20-inch tire and tube before attempting your first ride.
What Type of Battery Do I Need?
You'll need a battery capable of providing 48 volts of DC power at a minimum rate of amperage sufficient to support a continuous load of 1000 watts. Your battery must also contain connectors compatible with those supplied within the kit. Please review our ebike batteries comparison article to determine which battery meets your needs.
Will It Fit My Frame?
If your bike's rear fork has dropouts with an inner width of 135mm, it will fit. However, it's always a good idea to verify measurements before making your purchase.
Will I Have to Replace My Brakes?
No. Provided your brake pads/calipers line up with the rim or rotor after installation of the new wheel (motor wheel), you won't need to replace them.
How Fast Can I Go?
The manufacturer specifies a top speed of approximately 31 mph (50 km/h). Actual speeds depend upon rider weight and what voltage/amperage combination your battery provides.
What Should I Check Before Ordering?
Three things. Your bike's rear dropout spacing should measure 135mm. You should have a 20-inch tire and tube ready before install day, since the kit ships without them. And your battery should be 48V with connectors matching the kit's wiring. Miss any of the three and you are either ordering adapters or shipping something back.
Is This a Good Kit for a First Conversion?
It is a reasonable first build. The wheel arrives pre-laced, so there is no spoke work. The wiring is a color-matching exercise where the consequences of getting it wrong are obvious but fixable. And the display shows everything a new builder actually needs. Take your time on the phase and Hall wire connections, and the rest is basic hand tools.
What Maintenance Does a Gearless Hub Need?
Almost none. There are no gears to service and no brushes to wear out. The sealed hub just needs its axle nuts checked tight after the first few rides and the cable connections inspected occasionally. Compare that to a mid-drive setup with chainring and chain wear, and you can see why commuters like direct drive.