Jasion RetroVolt 330 vs TST Fat Retro

Quick answer: Jasion RetroVolt 330 or TST Fat Retro?

• Buy the Jasion RetroVolt 330 if you want to carry a passenger. Its bench is marketed for short passenger trips and it publishes a 330 lb payload. The TST publishes no payload at all.
• Buy the RetroVolt 330 if you want the spec sheet that says more. Its listing states the battery voltage (48 V 15 Ah) and a rider height range; the TST gives "15AH" with no voltage.
• Buy the TST Fat Retro if a smartphone app matters to you. It pairs an LCD with an app, which is unusual at this price.
• Buy neither if you need a documented street-legal e-bike. Neither publishes a rated wattage, and the only top speed on record is the 30 mph Jasion lists for the RetroVolt, above Class 3.

Side-by-side specs

Every figure is the seller's or maker's own claim, as recorded in our two reviews. We have not ridden either bike.

Which is faster, the RetroVolt 330 or the TST Fat Retro?

Neither can be called faster from the documents, because Jasion's store lists the RetroVolt 330 at 30 mph and TST publishes no top speed for the Fat Retro. Neither Amazon listing states a top speed. Both claim a 2000 W peak motor, and a 2000 W peak motor on 20x4 tires is built to go well past 20 mph. If either display lets you set a limit, 20 mph keeps the bike inside the Class 1 and Class 2 speed rule. That fixes speed only; it does not supply the missing rated wattage.

Which is street legal?

Neither the Jasion RetroVolt 330 nor the TST Fat Retro can be shown to be a street-legal e-bike from its own documents. The US three-class system caps Class 1 and Class 2 at 20 mph and Class 3 at 28 mph with pedal assist only, and the federal consumer-product definition in 15 U.S.C. §2085 is written around 750 W rated output. A peak figure is not a rated figure.

• Jasion RetroVolt 330: the Amazon listing gives a 2000 W peak and no rated wattage. Jasion's own store lists 30 mph, which is faster than Class 3 allows, so as its manufacturer describes it the bike fits no US e-bike class.
• TST Fat Retro: the listing gives a 2000 W peak, no rated wattage and no top speed, so its class cannot be determined from the listing. If it arrives limited to 20 mph with a legal rated plate on the motor, it would ride as Class 2.

New Jersey and Hawaii also require e-bike registration. If a documented class matters more than the moped look, both brands sell a bike that publishes a rated motor: TST's Fat 20 prints 750 W rated, and Jasion's EB5 MAX publishes 750 W rated with a 28 mph Class 3 speed. Check your state on the street-legal-by-state guide.

Which goes further on a charge?

Neither goes meaningfully further: both carry about 720 Wh, and our planning figure for each is 30-35 miles. Realistic e-bike consumption is 15-30 Wh per mile, and a heavy fat-tire bike on a 2000 W peak motor sits toward the top of that range.

• RetroVolt 330: "up to 70 miles" from 720 Wh needs 10.3 Wh per mile. The 70-mile claim fails the arithmetic.
• TST Fat Retro: 65 miles from about 720 Wh needs about 11 Wh per mile, and a 4-inch tire with an upright rider draws closer to 20.

The one real difference is certainty. Jasion's listing states 48 V 15 Ah, so 720 Wh is its own figure. TST's listing says only "15AH"; the 720 Wh is our arithmetic on an assumed 48 V. Jasion's store sells the RetroVolt 330 with an 18 Ah (864 Wh) pack, but the Amazon listing sells the 15 Ah version, so expect 720 Wh.

Which is better for two riders?

The Jasion RetroVolt 330 is the better choice for two riders, because it is the only one of the pair marketed for a passenger and the only one with a published payload. The listing markets the rear seat pad for short passenger trips and gives 330 lb, which has to cover both riders plus anything you carry, and two average adults can exceed it. The TST Fat Retro publishes no payload and makes no passenger claim. Many states restrict carrying a passenger on a bicycle not designed and equipped for it, so check local rules first.

Which is more comfortable?

They are close, and the RetroVolt 330's rear suspension is the better documented. Jasion's product photos show a coil shock under the seat frame as well as the front fork, which rules out the sprung-seatpost shortcut some "dual suspension" listings use. The TST listing claims dual suspension on 20x4 tires, and our review does not document the rear design. Neither publishes suspension travel. The RetroVolt's minimum saddle height of about 34 inches is tall for riders at the 5'4" end of its stated 5'4" to 6'3" range.

Verdict

For most riders the Jasion RetroVolt 330 is the better buy. It was Amazon's #1 Electric Fat Bike in September 2026, it states its battery voltage, it publishes a 330 lb payload with a bench meant for a passenger, and it cost $539.99 (as of Sep 16, 3:16 PM EDT, subject to change) against $579.99 (as of Sep 16, 3:16 PM EDT, subject to change) for the TST at our last check. The TST Fat Retro earns its place if the smartphone app matters to you; its stated warranty is 180 days, half the usual year.

Neither is the bike to buy for bike lanes and paths. Neither publishes a rated wattage, both range claims fail the arithmetic, and neither names a UL standard. Treat both as comfortable moped-style bikes for private land and for places that do not enforce the class system, and set a 20 mph limit if the display allows it.

Read the full Jasion RetroVolt 330 review and the full TST Fat Retro review. For the #3 bike in the same chart, see DEEPOWER QS7 vs Jasion RetroVolt 330. For fat-tire bikes whose class can be placed, see the best fat tire electric bikes under $1,000.