Jasion EB5 Ultra Fat-Tire E-Bike

52 V x 20 Ah is 1040 Wh. Higher voltage is not a marketing trick here: at 52 V the same power draws less current than at 48 V, which means less heat in the controller and less voltage sag under load on a climb. Combined with the capacity, it is the most usable energy store of any bike we have reviewed.

Running the arithmetic, with a heavy fat-tire bike drawing 20-30 Wh per mile:

• 1040 Wh / 30 Wh per mile = 35 miles (throttle-heavy riding at speed)
• 1040 Wh / 25 Wh per mile = 42 miles (our planning figure)
• 1040 Wh / 20 Wh per mile = 52 miles (moderate assist, flat ground)
• 1040 Wh / 70 miles = 14.9 Wh per mile, which is what Amazon's "70 miles" claim requires
• 1040 Wh / 90 miles = 11.6 Wh per mile, which is what Walmart's "90-mile range" claim requires

Amazon's 70-mile figure is the most nearly credible range claim in this batch — optimistic for a fat bike, but within sight of reality for a light rider in low assist rather than off by half. Walmart's 90 miles is not: 11.6 Wh per mile is below what this bike draws with a rider aboard. Plan on 40-45 miles.

The hydraulic brakes deserve equal billing. Almost every bike at this price uses mechanical discs, which need cable adjustment as the pads wear and give less modulation. On a bike this heavy, with this much power, hydraulic brakes are the difference between stopping confidently on a descent and learning where the cable slack went. A handful of cheaper bikes we review also claim hydraulics, but they pair them with far smaller batteries; nothing else we track puts hydraulic brakes and a 1040 Wh pack on the same frame under $1,000.

The US three-class framework is defined by two figures: motor output and speed. Class 1 is pedal assist to 20 mph, Class 2 is a throttle capped at 20 mph, Class 3 is pedal assist to 28 mph. The federal low-speed electric bicycle definition in 15 U.S.C. §2085 is built around 750 W rated, and only Oregon sets a higher ceiling, at 1,000 W.

The Amazon listing publishes neither. It quotes 2500 W peak, which is not the regulated figure, and states no top speed anywhere on the page. Jasion's own store does not carry the Ultra at all — the EB5 Roamer and Roamer ST are the only EB5 bikes on jasionbike.com — so we went to the other retailer selling it. Walmart lists the same bike (item 21026505555) at 28 MPH. That is exactly the Class 3 ceiling, which means the bike is plausibly a Class 3 machine rather than an unclassifiable one, and it is the single most useful fact about this bike that the Amazon page omits. It still does not supply a rated wattage, so there is nothing to test against the 750 W federal figure, and a 2500 W peak motor is a long way above what a 750 W rated hub normally peaks at.

In practice, a 2500 W peak motor on 26-inch fat tires will exceed 20 mph comfortably, which is the assumption to make until Jasion publishes otherwise. Treat it as an off-road and private-land bike, ask the seller for the rated wattage before you ride it in a bike lane, and read your state page first: seven jurisdictions ban Class 3 outright (DC, Kentucky, Massachusetts, Montana, North Carolina, Pennsylvania and South Carolina), and an unclassed bike is in a worse position than a Class 3 one, not a better one. Our street-legal guide covers the rule where you live.

If you want a Jasion with a documented class, the EB5 MAX at $549 publishes a 750 W rated motor and a 28 mph Class 3 speed, and the Roamer ST at $719.99 names UL 2849 in its listing title.

The listing makes no UL claim: neither UL 2849 for the electrical system nor UL 2271 for the battery pack is named, and no certificate number or laboratory appears. Jasion does hold UL 2849 on at least one other model — the Roamer ST says so in its own title — which shows the paperwork exists inside the company but has not been claimed for this bike.

A 1040 Wh pack is a large amount of energy to store in a hallway, so this is the bike where indoor-charging rules bite hardest. 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 sales from 1 January 2026, and many buildings ask for the certificate before allowing a battery indoors. Ask Jasion for it before buying if that is your situation.

Jasion sells three bikes our readers regularly confuse. The EB5 at $199 is the entry model and the best seller of the three by volume. The EB5 MAX at $549 adds a 1500 W peak motor and publishes a Class 3 rating. The Ultra is the top: more battery than either, hydraulic instead of mechanical brakes, and a rear shock rather than a fork alone.

The honest summary is that the Ultra is the one worth buying if you are going to ride it hard and far, and the EB5 is the one worth buying if you want a fat bike for occasional use and want to spend half as much. The middle option is the hardest to justify. If you want the same money spent on a moped-style bike instead, the RetroVolt 330 at $599.99 is Jasion's best-selling bike overall.

The listing states a 330 lb payload and includes a rear rack, full fenders, a headlight and a brake-activated tail light. It does not publish a bike weight, which on a 26-inch fat bike with a 1040 Wh battery is likely 75-85 lb: enough that lifting it into a truck bed is a two-person job. Five levels of pedal assist and a seven-speed drivetrain handle the gearing, and the listing says it arrives largely pre-assembled.

One practical point specific to the big battery: charging 1040 Wh takes longer than charging a 500 Wh pack from the same charger, so expect a full charge to be an overnight job unless Jasion ships a fast charger, which the listing does not state.

Buy this if you want the longest range and the best brakes available on a fat bike under $1,000, you ride off-road or on private land, and you can accept that the class question is unanswered. Skip it if you need documented certification, if you need to know the top speed before you buy, or if $800 is above what you wanted to spend — the standard EB5 delivers the same format for far less.