Let me get this out of the way up front. A 2000W rear hub on a 20x4 fat tire bike is a heck of a motor for just a little bit of wheel. The HuaShuani 48V 2000W conversion kit packs some serious horsepower into a small fat tire rim, and at approximately 27 pounds of wheel and hub, it pulls like crazy. However, it also averages a 3.7 out of 5 star rating based upon 14 reviews, and there's one review out of those regarding a burned-out motor after 1 week of use. The reason this kit is worth learning more about before handing over your money is directly related to that exact split.
This is a spec analysis using genuine reviewer feedback. Consider all information listed below as a specification analysis of what the listing lists as specs, what owners report, and what you'll need to watch for.
Specs and Build Quality
Headline number equals 2000W. That is not a typo. Nor is that number a commuter motor. At a 48V system putting out 2000W, we're talking massive amounts of current draw, and thus massive amounts of torque at the rear axle. The listing states that the motor has a 550rpm motor rotation speed and that the no-load riding speed of the bike will be approximately 34 miles per hour. Remember the term no-load in regards to speed numbers. No-load speed numbers are the speed numbers you receive when you lift the bike off the ground and pin the throttle. Your actual top speed on pavement will likely be less than that, and will depend greatly upon how much weight you weigh, how tight your tire pressure is, and what type of grade you are riding on.
The construction of the kit consists of alloy steel and aluminum. Alloy construction is important since a 20x4 fat tire rim needs to be quite stiff. Fat tire rims are wider and heavier than standard wheels. Therefore, if you attach a 2000W hub to a flimsy rim, you will end up breaking spokes. The alloy construction combined with the 27.2-pound item weight indicate that you may be able to purchase a relatively sturdy wheel. However, do make sure to stress test the spokes and true the rim prior to taking your first full-power ride.
The kit comes equipped with an LCD screen. The screen displays your speed, power usage, distance traveled, your current voltage levels, and the amount of amperage you're pulling. Additionally, the LCD screen also has a fault display option which is quite useful when dealing with high powered builds such as this. As mentioned above, displaying voltage and current is definitely not fluff when working with a 2000W motor. Both of these readings allow you to monitor the battery drain in real time and pull away from the situation before things get cooked.
You receive five adjustable gear settings and cruise control for fixed speed. Cruise control is an excellent addition for when you're cruising down a long flat stretch. You can choose to operate either in pedal assist mode, which is foot pedal assist, or pure electric mode, which is throttle-only operation.
Here's what truly impressed us. The controller functions via Hall effect sensors and non-Hall effect sensors. If any of your Hall effect sensors fail, then the controller will automatically transition to sensor-less mode and continue operating your motor. That is an incredible degree of failure tolerance. Many low-cost kits lose functionality immediately once a Hall effect sensor fails. This unit allows you to roll home.
Installation and Compatibility
This is a 20x4 fat tire rear-wheel kit. Therefore, this is intended for use with bicycles utilizing 20-inch diameter rims and four-inch wide tires. Do not attempt to install this kit onto your standard mountain bike, or any bike that does not utilize a 20-inch diameter by 4-inch wide tire. It will not fit. Check your dropout width and ensure that your frame clearance is sufficient before making any purchases.
Installing a rear wheel kit is significantly more involved than installing a front wheel kit. You have to account for your drivetrain side, cassette or free-wheel, your dropouts, and your wiring path back to the battery. Motor cables run along the chain stay and up to the controller. Therefore, consider purchasing zip ties and cable organizers prior to completing the installation. In addition to the motor cables, you will require axle torque arms. Due to the fact that this is a 2000W motor installed into a rear hub, torque arms are mandatory in this application. Without proper bracing, the axle will rotate within the dropouts and will ultimately prevail.
The kit includes an intelligent PAS, pedal assist sensor, that monitors pedal frequency. When pedaling, the motor will engage with your pedal stroke, thereby providing a smoother ride experience as opposed to relying solely on cadence switching. On a fat tire bicycle weighing several hundred pounds, experiencing motor engagement at each pedal stroke rather than post-pedal stroke provides a far superior feel.
Battery is not included. That is a major point on the specifications page. You are purchasing the wheel, motor, controller, display, and PAS, but no battery or charger is included with your order. Make certain to factor in the cost of the battery and its mounting requirements into your overall project costs.
What Amazon Reviewers Are Saying
At present time, this product has been reviewed by 14 reviewers resulting in an overall rating of 3.7 stars out of 5. With respect to a product with a maximum power output of 2000W, we would prefer seeing glowing reviews on products with this level of capability. Unfortunately, we see two vastly different perspectives presented in the reviewer comments section, and you should take note of both.
Admiral Indigo awarded it a rating of 5 stars stating perfect. Admiral stated his son quickly assembled an e-bike due to this kit. He rated the speed as perfect, indicated it was well worth the wait and the cost, and had no complaints whatsoever. Admiral's comment represents a clean build experience. All items were received intact, he completed assembly of the bike, and it worked perfectly.
Kimberly gave it a rating of 1 star with her title being Buyer beware. She stated that the motor failed on her second ride and produced extreme heat during said failure. Kimberly attributed this to either cheap controller or cheap hub motor and further noted that in comparison to other Amazon hub motors, she felt this kit wasn't inexpensive. The bad news for Kimberly was that she couldn't contact anyone from the manufacturer, only provided her opportunity to initiate a return, and that this e-bike was used as her primary ride-to-work vehicle.
The above-mentioned Kimberly review is the one that should scare you. A motor producing extreme heat during its failure indicates an excessive amount of current being drawn through the motor as a result of an overly aggressive controller setting or inadequate heat dissipation capabilities from the motor itself. Heat loss on a 2000-watt build is potentially catastrophic. In addition to this issue, Kimberly expressed concern regarding communication issues with customer service personnel at HuaShuani, specifically indicating that her attempts at contacting them only resulted in her ability to initiate a return process. Please don't assume after-sales support will exist here.
Who Is This Kit For?
If you desire building a fat tire behemoth capable of hauling down trails, snow, or sand, or are simply willing to accept higher power hardware risks associated therewith, then this kit is designed for you. The 2000-watt motor mounted onto a 20x4 fat rear wheel is going to provide an enormous amount of torque, ideal for hauling up hills or performing other types of trail-based operations requiring rapid acceleration.
However, if reliability is paramount to you, and you cannot afford down time, then you may wish to reconsider purchasing this kit. One reviewer already experienced a motor burn-up after one week of use, and even though HuaShuani offers only thirty days of warranty coverage, there isn't much protection offered once you've purchased this kit. Kimberly discovered this truth firsthand.
Lastly, please recognize that this kit isn't suitable for new builders either. This kit requires significant knowledge and skills relative to higher-power electrical systems, including knowledge of controllers, current flow and drainage, and battery sag characteristics. If you want to compare this against other hub options, check out our guide to ebike conversion kits before you commit. Browse more build advice on the blog for sizing and safety guidance across different setups, and ebikes.ca is a solid resource for controller and battery knowledge.
Frequently Asked Questions
Does this kit include a battery?
No. The battery is not included. You need to supply a 48V pack and a charger. Budget for that cost and for frame mounting before you order. A battery big enough to feed 2000W without voltage sag is a major part of the total build.
What size bike does this fit?
This is a 20x4 fat tire rear wheel. It fits 20 inch rims with 4 inch wide tires. Measure your wheel size and tire width before buying. It will not fit standard 26 inch or 700c bikes.
Is 2000W and 34 mph realistic?
The 34 mph figure is a no-load speed. That is the wheel spinning free at 550rpm. Real world top speed is lower and depends on weight, tire pressure, grade, and wind. Expect fast, but do not expect the marketing number on pavement with you on it.
What happens if a Hall sensor fails?
The controller is designed to run in both Hall effect and non Hall effect modes. If a Hall sensor breaks, the controller switches to sensorless operation and the motor keeps running. That is a genuine reliability feature and a reason to consider this kit over cheaper ones.
How long is the warranty?
The listing shows a 30 day warranty. That is short for a 2000W motor. One reviewer reported difficulty reaching the company and was pushed toward a return instead of a repair. Keep that in mind if you are relying on this as a daily rider.
Do I need torque arms?
Yes. A 2000W rear hub motor will try to spin the axle inside the dropouts. Torque arms are not optional at this power level. Brace the axle and check it after the first few rides.
If you want cheap watts and you understand the risks, grab the HuaShuani 48V 2000W conversion kit on Amazon. If you need a dependable daily commuter, keep looking.