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King Song 14" 500w 520wh Self Balancing Electric Unicycle Review

Our King Song KS-14C 520wh has been purchased for full price, and has arrived! Here's the unboxing video: is now riding the King Song KS-14C 520wh 14" self balancing electric unicycle. Of all the brands we've tried, I think that this is the best value for money. I like riding it better than I like riding my Ninebot One E+. It feels better on my legs, rides smoother and faster, and has more power.

King Song is the only manufacturer who has addressed every known reason for unexpected shut-down. They address every concern we raise, and answer every question we ask about quality, design, and safety features. Based on my experience so far, I now feel safe letting my lady ride this one, and look forward to more from King Song in the future, including an upcoming review of the 800w version. I also feel confident offering this brand of micro unicycle in our store, and recommend this as the best and safest uni available.

There is a new app on the way! It will be available for iOS and Android. We will be adding a section to this review detailing the features.

On our site, everyone is choosing the 800w 680wh version. There are reviews on the internet forums, and based on the Nerds in the Know on there, I feel confident that, along with the 520wh version, it is the safest micro unicycle available anywhere right now. Here's a post listing all the safety features (link here).

First Impressions

It's YELLOW! And fast. And it makes a sound like a muscle car (muscle unicycle?). Ok, maybe it sounds like a moped for a furby. The sound of a happy motor.

This is the most compact micro unicycle I've tested so far, despite being the fastest and having the biggest battery by far. With the 520wh battery, it's pretty hefty! The 14 inch wheel means maneuverability, but King Song seems to have created firmware that makes it a very smooth riding experience for the wheel size.


The Sound

When I discovered the sound of the King Song, I thought, "What is this noise?" My conclusion has been, the sound of the King Song has a lot less variation than the other unicycles I own and have tested. What I like about that is, it fades into the background like a sort of steady white noise. I'll try to describe it in text:

King Song: eeeeeeeeeeeeeeeeeeeeeeeeEEEEEEEEEEEeeeeeEEEEEEeeeeeee

Ninebot: WeeeeeooooooooooohhhwweeEEEEEeeeoooooohhhhhhweeeeEEE

Every uni has a distinctive sound, kind of like every car has a sound. They all make a different sound, but the King Song is the steadiest one I've ridden. Based on conversations on the forums, it's not the loudest and not the quietest - one person said the Gotway MSuper goes to "11" compared to his King Song.

I'm a veteran blender salesman by trade (22,000 hours+ of Vitamix demonstration, no joke), and because I've blended so much ice in different proportions and variations I have an intimate relationship with the sound of a struggling motor :). To me the King Song sounds like it has power to spare, compared to nearly all other unis I've tested and owned which all sound like they're sort of struggling. That's one reason King Song is my favorite.

There is a rumor that the high-speed beep is fairly loud, and this is one of my favorite things about the King Song. Other unis I've tested have beep features that I just can't hear well enough, and it's important to get feedback when you're riding. The newest versions are more adjustable as well, allowing one to change the beep volume and ride settings.

Materials quality and design

The design of the King Song KS-14C is relatively compact and modern. It fit under the chair at the coffee shop more easily than the Huanxi or the Ninebot we also own. Compared to the Huanxi H1 (link here), and also the "old style mold" like the TG-T3 (link here) the look is less cute and friendly, and more aggressive. Someone compared the character to the Subaru WRX STI, and I totally get it. Not the prettiest thing, butjust wait til you see what that baby can do! It's just under average width at 20cm. Comfort is excellent because of the thick, wide, high quality padding. The 174wh version is about 3cm narrower (thickness of the unit) and offers a swappable battery, but the 520wh and 680wh have the right number of battery cells to support the motor, and will be the safest.

We had heard reports that King Song unicycle body material was very thin, so I wanted to make sure that there were no quality concerns. The polycarbonate body is sturdy, and seems to be form fitting to the working parts inside. From my blender salesman days, I know that polycarbonate is an extremely strong material, the same one as airplane windows and bullet proof glass. Of course, it would be much thicker in bulletproof glass, so don't go shooting your unicycle and expecting a warranty repair. Here's a video of someone beating a King Song shell silly (link here). As you can see, the shell is indestructible. Compare with most brands near the price range, who are using brittle ABS plastic. I also squeezed it and pulled the parts, and the build was tighter and less creaky than the Ninebot One E+, also reviewed on this site.

The pedals are huge, and rectangular with rounded edges. When they're open, they have a slight inwards angle forming a gentle "V" which feels wonderful. They fold flat and close to the body of the unicycle, and stay up. There is a little bump on the bottom of the pedals, that you can see on the stock pictures I have posted here. These aren't too rough on the leg when carrying the unit, and I'm happy with the design compared to the more conventional pedal shapes I've reviewed in the past, such as the Airwheel X8. There was a rumor that the pedals could act as a kickstand, but they do not support the weight of the 520wh version. Maybe with the lighter 174wh battery version.

One minor gripe is, the grip lines on the pedal are going in the wrong direction, forward and back, and would help grip better in wet conditions going outwards to the sides. I hear there will be a revision of this style in the coming months.

Power, Speed, and Range

I'm not the heaviest guy, at 160lb give or take (give). The KS-14C we reviewed has a 500w motor with "3000w peak output," and it seems like enough power for sure. The motor doesn't struggle like all of the 350w models I've tried (link here). It feels much more powerful and responsive than the Ninebot One E+ we have, perhaps due to the higher peak power output, and also perhaps because of the smaller wheel size. I asked my role models in the forums their opinion on the advantages of a high peak output motor, and the general consensus was that it means nothing until it is tested (link here).

Range is a funny thing, because it really depends on who is riding, how they ride, and where they are riding. At this time, I think it's best to estimate less than 20 mile range with the biggest battery they offer (680wh), but of course your mileage may vary.

The most important option available in the King Song line is the battery sizes 520wh and 680wh. These have 64 individual battery cells, which allows the uni to maintain a high enough voltage to take advantage of the motor's power, for the full charge. Brands which have about 340wh (32 cell) or 172wh (16 cell) size battery packs have a much higher chance of "voltage drop," which can cause at best decreased motor performance, and at worst dangerous unexpected shutdown. So we recommend, get a big battery.

High Speed Unexpected Shut-off? Nope!

Most people are comparing these King Song units to the Gotway micro unicycles which were very popular in the last generation. Here's a comparison of the actual electronic control boards (link here). Gotway unis are famous, firstly for being fast. They are also famous for something else: unexpected high speed main-board shutdown. Here's why:

Most brands tilt back and beep to tell you to stop going faster, and some talk to you. Some unicycles will just go faster and faster until they turn off because the motor can't take it anymore. Gotway and Rockwheel are examples that will experience a speed-cliff type mainboard shutdown.

King Song avoids high-speed main board shutdown by implementing a high-speed tilt-back, but according to hobby16's page it also includes an aluminum heat sink in a high airflow location to lower main board temperature. So, it's the natural limitation of the device. King Song uses tilt-back and efficient cooling to protect the rider from riding in a manner that triggers the unexpected shut-down, which occurs when reaching/sustaining a speed above the tolerance of the motor. Gotway units on the market now were designed in a way that allows the rider to push the limits, giving the rider the added responsibility of knowing what those limits are.

At high speeds, the unit beeps and tilts back. This is absolutely key, because the famous and desirable Gotway unicycles don't do this. Instead, they consistently turn off when you push them too hard and you crash at around 15mph. That's why I don't offer Gotway in the store. King Song has addressed every known type of shut-off, and that's why they're the brand we recommend for safety. Independent tests have verified that King Soing unis are at worst very difficult to get to shut down, and at best impossible to shut down unexpectedly.

I prefer to take the safe route, and that's one reason King Song is my favorite brand of micro unicycle.

Low Battery Behavior

The battery is HUGE! Per dollar, the best range out there. So you're likely to never experience low battery at all. However, I will be pushing this little uni to the limit soon publicly; expect a video.

One important feature King Song has implemented is the "locking low battery tiltback," which makes it impossible to ride on low battery, forcing the user to charge before riding again. We looked everywhere for this feature. Finally!

When low battery occurs, there is a continuous beep and tilt-back, forcing the rider to pull over and walk. The unit will not let you ride on low battery, and will do a tilt back no matter what until it is charged. For now, see a video of the Huanxi doing this (link here).


The Good:

  • The only brand we can find who has addressed every known type of unexpected shutdown.
  • The cushions are beautiful and feel high quality.
  • The acceleration is a lot better than any of the Airwheels I've ridden, and any of the generic brands, as well as the Ninebot One E+.
  • The body feels narrower than the Gotway 14" micro unicycle I rode, which goes a similar speed.
  • The pedals are huge and have a great v-type angle. Very comfortable to stand on.
  • The rear light gets brighter when you brake, and there are speakers too.
  • The body of the unicycle itself is smaller than the Huanxi H1 we reviewed here (link).
  • The sound is steady and has less variation than other brands we've tested. It fades into the background, because it's not all over the place.
  • No beep when you turn it on.
  • Panasonic or LG brand name batteries. Excellent size for the price.
  • It will not let you ride when the electronics, battery or motor are near their limit. This means if you are heavy and you push it too hard, it will tilt back and need to cool down. This will keep you safer.
  • It's bright yellow.

The Bad:

  • The charger plug on the actual unicycle arrived a little loose. It jiggles a bit when I plug in. Works fine, but an imperfection.
  • This unicycle makes a sound all the time, which increases with speed.
  • I did not receive a manual.
  • The pedals don't act like a kickstand at all, as has been claimed in some YouTube videos.
  • There's an 800w version now. Always something better down the road!
  • It will not let you ride when the electronics, battery or motor are near their limit. This means if you are heavy and you push it too hard, it will tilt back and need to cool down. This might be irritating if it happens, but the alternative is a crash.
  • It's bright yellow.

Check back soon for a more detailed evaluation of the King Song KS-14C 520wh 14" self balancing electric unicycle. We update periodically, so there will be more!

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King Song 14

Scroll down for the technical specifications and list of features...

King Song 14

  • Top speed - 500W Motor (3000W peak) gives you speed of around 15mph (25 kph). Beeping alarm activates when exceeding 22km/h and more intensely above 25km
  • Range - 340Wh Panasonic 22-24mi (34-40km) / 520Wh LG 32-37mi (52-60km) / 680Wh LG 44-50mi (70-80km).
  • Charging Time - 340Wh (around 2.5h) / 520Wh (around 4.5h) / 680Wh (around 5.5h)
  • Weight - 13kg average, with variation for different battery sizes
  • Luxury features - LED front light & rear brake lights, 4 speaker Bluetooth stereo, and USB Port to charge electronics
  • Proprietary motor control software created in-house at King Song.
  • App control for Android and iOS.
  • Automatic restart after tilt alarm is activated. Reorient the unit and the alarm stops.
  • 10 Level LED bar will light up fully over 85%, then fade gradually one by one. Below 5% Power indicator blinks
  • Low battery protection activated on 10% battery - continuous beep. When the battery is lower than 5%, the front part of the pedal will rise to decelerate until full stop.

Charger Input: AC 80~240 V, Output: 67.2V、2A, Material - ABS+Polycarbonate, Machine Size (mm) - 447.5mm ( H) x 404mm (L) X 190mm (Thickness), Shipping Size - (mm) 460 mm(H)* 555mm(L)* 235mm(Thickness)

Pedal Distance from Ground - 110mm (without load), Tire Diameter - 14inch, Diameter 295mm, Interfaces - High quality waterproof charging port, power on/off button, Bluetooth on/off button, LED braking on/off button

Tilting Protection - 45° side to side left and right. Automatic restart., Maximum climbing angle - Around 25°, 60kg riders up to 30°, Operating Temperature - About -10°C/+60°C, Max Load - 120Kg

King Song 14