HQYEX 20" All-Terrain Fat Tire E-Bike

48 V x 20 Ah is 960 Wh. For context, the two best-selling fat bikes in this price band both ship 720 Wh: the Jasion RetroVolt 330 at $599.99 (as of Sep 25, 9:24 AM EDT, subject to change) and the TST Fat Retro at $579.99 (as of Sep 25, 9:24 AM EDT, subject to change). More watt-hours is the one upgrade that cannot be faked by marketing: it is volts times amp-hours, both printed on the pack. The bikes under $700 that beat it are the ASKGO Dirt 5500 at $599.99 (as of Sep 25, 9:24 AM EDT, subject to change) and the Xathquia Dirt 20 at $529.99 (as of Sep 25, 9:24 AM EDT, subject to change), which are dirt bikes built for closed courses rather than trail and road use.

What it buys you is honest distance. A fat-tire e-bike of this weight and power draws 15-30 Wh per mile depending on rider weight, assist level, terrain and speed, and a 1500 W peak motor on 20-inch knobbly tires lives in the upper half of that band. So:

• 960 Wh / 30 Wh per mile = 32 miles (throttle-heavy, faster riding)
• 960 Wh / 25 Wh per mile = 38 miles (mixed riding, our planning figure)
• 960 Wh / 20 Wh per mile = 48 miles (light rider, low assist, flat ground)
• 960 Wh / 60 miles = 16 Wh per mile, which is what the listing's "up to 60 miles" claim requires

Sixteen watt-hours per mile is achievable on a light commuter bike with a slim tire and a small motor. On a fat-tire bike it means pedalling hard in the lowest assist level. Plan on 32-38 miles, and treat 60 as the number from a test we cannot see.

The US three-class framework is the thing to understand before buying any bike that advertises a speed like this. Class 1 is pedal assist to 20 mph. Class 2 adds a throttle, still capped at 20 mph. Class 3 is pedal assist to 28 mph, and most states do not allow a throttle to carry a Class 3 bike past 20 mph. The federal definition of a low-speed electric bicycle in 15 U.S.C. §2085 is built around a 750 W rated motor and a 20 mph top speed under motor power alone.

Here the two retailers contradict each other, and the gap is the whole legal question. The Amazon listing we link claims a 1500 W peak motor and up to 31 mph. Walmart sells the same bike as the HQYEX HQ20 — same 48 V 20 Ah pack, same dual suspension, same dual disc brakes, same frame in the same photographs — and titles it 750 W and 20 mph. One of those descriptions is a Class 2 e-bike that is legal in all 50 states; the other is a machine that fits no class anywhere, because 31 mph is above even the Class 3 ceiling.

We cannot resolve it for you and we will not pretend otherwise: neither retailer publishes a rated wattage next to its peak figure, and HQYEX has no website to arbitrate. What we can say is which way to bet. A 20 Ah pack, a 31 mph claim and a moped frame are the signature of a bike sold on power, and the safe assumption is that it will exceed 20 mph out of the box. Seven jurisdictions ban Class 3 outright (DC, Kentucky, Massachusetts, Montana, North Carolina, Pennsylvania and South Carolina), and a bike above Class 3 is outside the system in all fifty.

In practice that means: private property, OHV areas and campgrounds are fine; bike lanes and multi-use paths are a risk you are choosing to take. If the LCD menu exposes a speed limiter, setting it to 20 mph solves the speed half of the problem, though it cannot supply the missing rated figure. If you want the fat-bike format with a class you can point at, the Funhang Fat 26 at $459.99 (as of Sep 25, 9:24 AM EDT, subject to change) is the honest alternative. Check your own state first on our street-legal guide.

The listing makes no UL claim at all — not UL 2849 for the electrical system, not UL 2271 for the battery pack, and no certificate number or testing body is named. That matters in three places. New York City's Local Law 39 of 2023 bans the sale of uncertified e-bikes and batteries in the city. California's SB 1271 requires certification for e-bikes sold there from 1 January 2026. And many apartment buildings now ask for the certificate before they will allow indoor charging.

An absent claim is not proof a bike is unsafe, but it is a real gap, and a 960 Wh pack is a large amount of energy to store in a hallway on trust. If certification is a requirement for you, the Vivi ACE01 at $561.99 (as of Sep 25, 9:24 AM EDT, subject to change) and the DTTZH F6 at $439.98 (as of Sep 25, 9:24 AM EDT, subject to change) both name UL 2849 on their listings.

The listing describes front and rear suspension, and the product photography shows a coil shock in the rear triangle rather than a sprung seatpost, which is the usual substitute at this price. Travel, damping and spring rate are not published, so read "dual suspension" as "there is a shock at each end" and not as a quality claim.

The rest is standard budget fat-bike equipment: a seven-speed derailleur, mechanical disc brakes front and rear, an LCD display and a 20 x 4.0 tire on both ends. The listing says it arrives 90% pre-assembled and carries a one-year manufacturer warranty. It does not publish a bike weight or a payload limit, which is a gap worth knowing about if you are a heavier rider: comparable 20-inch fat bikes run 70-80 lb with a 300-330 lb payload, but HQYEX does not commit to either figure.

One practical note on the wheel size. A 20 x 4.0 tire makes the bike short, stable and easy to store, and it keeps the standover height low, but it also makes it slower over broken ground than a 26-inch wheel and busier to steer at speed. If you mainly ride rough trails, a 26-inch fat bike such as the Jasion EB5 at $199 (as of Sep 25, 9:24 AM EDT, subject to change) will roll over obstacles more calmly.

Buy this if you want 960 Wh of battery for under $600 and you ride mostly on private land, trails, campgrounds or quiet roads where the 31 mph claim is not a legal problem. Skip it if you need a certified battery, if you commute in a bike lane, or if you want published weight and payload figures before you spend $600.