E-bike motor wattage explained

Rated, peak and nominal

Three words appear on motor specifications and they are not interchangeable. Getting them straight is most of the work.

Rated (or nominal) power is the output a motor can sustain more or less indefinitely without overheating. "Nominal" and "rated" are used interchangeably in practice, and this is the figure US law generally refers to. It is the number that describes what the bike does on a long climb, into a headwind, on a hot day — the moments that actually test a motor.

Peak power is the maximum the motor and controller can produce in a short burst, typically for seconds rather than minutes, before heat forces a reduction. Peak is real and useful: it is what pulls a heavy bike away from a standstill or over a short rise. It is simply not what the bike does continuously.

The marketing incentive is obvious. Peak is roughly 1.5 to 3 times rated on most systems, so a brand quoting peak gets a headline two or three times larger for the same hardware. A listing that says "3000W" without qualification is almost always quoting peak.

Across the twenty-two bikes, the rated figures are: 350W on the Velotric T1 ST Plus, the lowest rated motor here; 500W on the VTUVIA Zeal LT7, the EUNORAU META26 and Velotric's mid-drive Discover M; 750W on the VTUVIA SF20H, SX20 and SN100, on the EUNORAU FLASH Lite in its base configuration, and on Velotric's Nomad 1 Plus, Packer 1, Discover 2 and Discover 3; 1000W on the AMYET V9-G60, AMYET EB26, AMYET K10, EUNORAU FLASH, EUNORAU SPECTER-S, EUNORAU SPECTER-ST, VTUVIA Gemini and VTUVIA FMB; and two 1000W motors on both the AMYET S8 and the AMYET Ares 2. Peak claims follow where published at all: 600W for the T1 ST Plus, 750W for the Zeal LT7, 960W for the Discover M, 1100W for the Discover 3, 1200W for the SF20H and SX20, 1300W for the FMB, 1500W for the G60, EB26, K10 and Gemini, and 3000W combined for both the S8 and the Ares.

When you compare bikes, compare rated against rated. Comparing one brand's peak with another's rated is the most common mistake in this part of the market, and it will reliably point you at the wrong bike.

What a wattage figure actually predicts

Watts measure the rate of doing work. More watts broadly means faster acceleration, a higher speed the motor can hold, and more capacity to move mass uphill. A 1000W-rated motor has real headroom: a fit cyclist sustains 150 to 250 watts, so the motor contributes several times what a strong rider can.

What a wattage figure does not tell you:

• How the power is delivered. Two 1000W motors can feel completely different depending on winding, controller tuning and where in the speed range the torque arrives. The 1000W hub in the AMYET G60 and the 1000W Truckrun mid-drive in the EUNORAU FLASH share a number and almost nothing else.
• How it climbs. Climbing is a torque problem at low wheel speed, and watts are torque multiplied by rotational speed. A motor producing its rated power at 25 MPH may be producing very little of it at 5 MPH on a steep pitch.
• How long it holds. Thermal behaviour is not in the wattage figure at all.
• How efficient it is. Rated output says nothing about what the pack pays to produce it, which is a range question — handled in our battery and range guide.

The practical version: past about 750W, extra rated watts buy less on flat ground and more on hills and under load. If you commute on the level, the difference between 750W and 1000W is barely perceptible. If you climb, it is not — but even then, watts are the wrong number to be reading.

Torque is the number you actually want

Torque is rotational force, measured in newton-metres. It is what gets a loaded bike moving from rest and what keeps it moving up a gradient at walking pace. Watts describe the rate of work; torque describes the shove.

For a rough sense of scale on hub-motor bikes: around 45 to 60 Nm is adequate for gentle terrain, 65 to 80 Nm handles most real hills with an average rider, and above 80 Nm starts to feel effortless on steep ground. Mid-drive systems quote torque at the crank rather than at the wheel, so the numbers are not directly comparable between the two types.

Sixteen of the twenty-two bikes here publish a figure, and the ladder is instructive:

• 40 Nm — Velotric T1 ST Plus, a 350W hub. The lowest figure here, in the lightest bike here, on the narrowest tires we cover — a motor asked to move 39 lb rather than 70.
• 55 Nm — EUNORAU META26, a 500W hub. The lowest of EUNORAU's five, and honest about being a flat-and-rolling commuter.
• 65 Nm — VTUVIA Zeal LT7, a 500W hub, paired with a torque sensor and 27.5-inch wheels.
• 75 Nm — Velotric Nomad 1 Plus, Packer 1, Discover 2 and Discover 3, all 750W hubs: the same figure on a 70 lb fat bike, a 75 lb cargo bike and two 27.5-inch commuters.
• 85 Nm — VTUVIA SF20H and SX20, both 750W hubs.
• 92 Nm — EUNORAU FLASH Lite in its rear-hub configuration, from a 52V 750W motor.
• 100 Nm — VTUVIA Gemini, rated 1000W. VTUVIA does not state where this motor sits, so we do not call it a hub. The figure is above the 92 Nm of EUNORAU's FLASH Lite rear hub, which is the highest torque any bike here states from a confirmed single hub motor, and above the 85 Nm of the SF20H and SX20. Velotric's Discover M also states 100 Nm, but from a 500W mid-drive, which is a different measurement in the same units.
• 160 Nm — EUNORAU SPECTER-S and SPECTER-ST and VTUVIA FMB, all three from a 1000W Bafang G510 mid-drive.
• 184 Nm — EUNORAU FLASH Lite in its dual-hub AWD configuration, which is two 750W motors added together rather than one motor's output.
• 220 Nm — EUNORAU FLASH, a 1000W Truckrun mid-drive through Shimano 8-speed gearing.

The row that matters most is still the comparison it invites. VTUVIA's SF20H is rated at 750W and publishes 85 Nm. AMYET's V9-G60 is rated at 1000W and publishes nothing. On a listing page the AMYET has the bigger number; on a hill, the number you would want to know is the one only VTUVIA gives you. VTUVIA's own Gemini makes the point twice over: also rated 1000W, and it publishes 100 Nm.

What you can reason about is indirect evidence. AMYET pairs the S8's two driven wheels with a 35 degree maximum slope claim, hydraulic brakes and full suspension — a coherent set of choices for steep ground. The Ares pairs two driven wheels with dual suspension and a folding frame, but carries no slope claim. The single-motor AMYETs carry no comparable claim either. If your route is genuinely hilly, our e-bike for hills guide works through what to look for.

Hub motor or mid-drive

This distinction matters more than the wattage figure printed beside it, because it decides whether the motor can use the bike's gears.

Hub motors

The motor sits inside the wheel hub, usually the rear, and drives the wheel directly. Its torque reaches the ground unmultiplied, whatever gear you are in. Hub motors are cheap, mechanically simple, quiet, and they put no extra load on the chain — which is why seventeen of the twenty-two bikes here are not mid-drives: all five AMYETs, five of six VTUVIAs, five of six Velotrics, the EUNORAU META26, and the EUNORAU FLASH Lite in the rear-hub configuration its listing prices. Twelve of those seventeen say outright that the motor is a hub; the other five — AMYET's S8, K10 and Ares and VTUVIA's Gemini and SN100 — never state where the motor sits, so we do not state it for them.

The weakness is the steep, slow climb. A hub motor forced to turn slowly under high load draws heavy current and converts a growing share of it into heat rather than motion. It cannot drop a gear to escape.

Mid-drive motors

The motor drives the crank, so its output passes through the drivetrain. Shift to a lower gear and the gearing multiplies motor torque exactly as it multiplies yours. This is why a mid-drive rated the same as a hub motor climbs so differently: the hub's 100 Nm arrives at the wheel as 100 Nm in every gear, while a mid-drive's crank torque is multiplied by whatever reduction you have selected.

There are five mid-drives here now, and the most important thing to say about them is that they are no longer all from one brand. EUNORAU has three: the SPECTER-S uses a Bafang G510, also sold as the M620, publishing 160 Nm through an SRAM NX 11-speed cassette; the SPECTER-ST uses the same motor and the same 11-speed cassette in a step-through frame; and the FLASH uses a Truckrun mid-drive publishing 220 Nm through Shimano 8-speed. VTUVIA's FMB uses the same Bafang G510 at 160 Nm, on full suspension. And Velotric's Discover M uses its own VeloCore mid-drive, rated at only 500W but publishing 100 Nm through a 9-speed Shimano Cues 11–46T cassette — the widest-range cassette on this site, and a wide cassette is precisely what turns crank torque into climbing. The EUNORAU FLASH Lite adds a sixth possibility by offering a mid-drive as one of three motor-position options.

The costs are price and wear. All that force runs through your drivetrain rather than around it, so chains and cassettes wear faster than on a hub bike. Below roughly $1,500 mid-drives remain rare in the US direct-to-consumer market: the five here cost $2,499, $2,499, $2,999, $2,999 and $2,999, which is the honest price of the capability.

Geared and gearless hub motors

Within hub motors there is a second split that listings rarely mention.

A geared hub contains internal planetary reduction gearing, so the motor spins fast while the wheel turns slowly. That produces more torque for a given size and weight, and it usually includes a freewheel so the motor does not drag when unpowered. The trade is a small amount of gear noise and a wearing part inside the hub.

A gearless or direct-drive hub has no internal gearing: the axle is the stator and the shell rotates around it. It is nearly silent, has almost nothing to wear out, and can support regenerative braking. It is also heavier for the same torque and less efficient at low speed, which is precisely where climbing happens.

None of the seventeen bikes here that are not mid-drives states geared or gearless. AMYET describes the EB26, S8, K10 and Ares motors as brushless, as VTUVIA does the Gemini and SN100, which every one of these motors is and which tells you nothing about internal gearing. If you are choosing between two otherwise similar bikes and one specifies a geared hub, that is a small point in its favour for hilly riding.

Why the drivetrain still matters on a hub-motor bike

It is tempting to dismiss the gears on a hub-motor e-bike. The motor is in the wheel; the cassette cannot help it. Ten of the seventeen bikes that are not mid-drives here list a 7-speed drivetrain and five Velotrics list Shimano 8-speed; the FLASH Lite is single-speed, and VTUVIA publishes no drivetrain for the Gemini. Wherever there is a cassette, it earns its place for three separate reasons.

• It lets you contribute usefully. Your own 150 watts only arrive if your legs are turning at a cadence that produces them. On a long climb, spinning a low gear at 80 rpm adds real power for twenty minutes; grinding a high gear adds almost nothing and hurts.
• It keeps the motor cooler. Every watt you add is a watt the motor does not have to produce. On a sustained climb that is the difference between a motor that holds its output and one that heats up and backs off.
• It makes the bike work with a flat battery. A 70-pound fat-tire e-bike is hard work to pedal unassisted, but a seven- or eight-speed range means hard work rather than impossible.

Seven speeds is modest, and Velotric's eight only marginally less so. The contrast with the mid-drives is the point: EUNORAU fits 8-speed to the FLASH and SRAM NX 11-speed to both the SPECTER-S and the SPECTER-ST, and Velotric fits a 9-speed Shimano Cues 11–46T to the mid-drive Discover M — the widest ratio spread here. On those bikes the cassette is not merely helping you, it is multiplying the motor. VTUVIA is the exception that proves the point: it publishes no drivetrain at all for the FMB, which is a $2,999 mid-drive whose gearing is the specification that decides what its 160 Nm is worth. Gearing does more work on a mid-drive than on any hub bike, which is why the two things are usually specified together.

Heat, and why bikes lose power on long climbs

A motor converts electrical energy into motion, and everything it fails to convert becomes heat. A hub motor is a sealed aluminium shell with limited surface area and no fan, so on a long climb heat accumulates faster than it can escape.

What happens next depends on the controller. A well-designed system monitors temperature and progressively reduces current — you feel the assist fade, which is frustrating but protective. A cheaper system without thermal monitoring simply runs hot, and sustained heat degrades magnets and winding insulation permanently.

This is the practical reason rated power matters more than peak. Peak is a promise about the first few seconds. Rated power is a statement about thermal equilibrium — what the motor can shed heat fast enough to keep producing. On a two-mile climb, the rated figure is the one you are riding.

A mid-drive escapes some of this by spinning faster while the wheel turns slowly, which is a more efficient place for an electric motor to work. Two habits help on any hub bike: pedal genuinely on climbs, and avoid holding the throttle wide open at low speed for minutes at a time. None of the four brands publishes thermal specifications or cutback behaviour, so this is category-level guidance rather than a description of these bikes.

Controller amps: the number almost nobody prints

Power is voltage multiplied by current. The battery sets the voltage and the controller decides how much current it will pass, so the controller is the component that actually determines the power ceiling. Fit a bigger controller to the same motor and the bike gets faster; fit a conservative one and a 1000W motor never sees 1000W.

Working the arithmetic on a 48V system:

• 48V × 15A = 720W
• 48V × 20A = 960W — roughly a "1000W" bike
• 48V × 25A = 1200W
• 48V × 31A ≈ 1500W — roughly a "1500W peak" bike

EUNORAU publishes the SPECTER-S controller rating rather than a peak wattage, which is the only controller figure on this site. It is the more useful disclosure of the two: 48 volts through 30 amps is about 1,440W of electrical input at full draw, and that is a ceiling you can reason about rather than a marketing headline.

Everywhere else it is inference. AMYET's 1000W rated and 1500W peak claims on the G60, EB26 and K10 are consistent with a controller passing roughly 20A continuous and around 30A in bursts; VTUVIA's 750W rated with 1200W peak is consistent with roughly 15A and 25A. Neither brand states controller amperage, and neither does Velotric on any of its six bikes, so those are readings of published figures rather than specifications.

Wattage, the law and the three-class framework

US e-bike regulation is set at state level and uses two levers: motor power and assisted speed.

The federal consumer-product definition of a low-speed electric bicycle refers to a motor of less than 750W, and many states have adopted 750W nominal as the ceiling for a vehicle to be treated as a bicycle rather than a moped. That sits awkwardly with a market full of bikes rated at 1000W and marketed at 1500W or 3000W peak. Enforcement is uneven, but the legal position is what it is, and it tends to surface after a collision or an insurance claim rather than at the roadside.

The three classes:

• Class 1: pedal assist only, assistance ends at 20 MPH.
• Class 2: throttle permitted, assistance ends at 20 MPH.
• Class 3: pedal assist to 28 MPH, frequently with restrictions on shared-use paths.

Seventeen of the twenty-two sort cleanly by claimed top speed. The VTUVIA SF20H, Zeal LT7 and SX20 are stated at 20 MPH as Class 2 machines, as are the EUNORAU META26 and FLASH, and all six Velotrics default to 20 MPH as well — the Packer 1 as a Class 2 machine unlockable to 25 MPH, the T1 ST Plus as Class 1/3 with a limit adjustable between 12 and 28 MPH, the Discover 2 and Discover 3 as Class 1/2/3 with the same adjustment, the Discover M with a class but no speed figure, and the Nomad 1 Plus with no class stated at all. The AMYET EB26, the AMYET K10 and the EUNORAU SPECTER-S are stated at 28 MPH, exactly the Class 3 ceiling. The AMYET V9-G60, S8 and Ares are stated at up to 32 MPH, outside all three classes in states that use the framework.

The remaining five publish no top speed at all: the VTUVIA Gemini, SN100 and FMB and the EUNORAU FLASH Lite and SPECTER-ST. A bike whose assisted speed is unstated cannot be placed in the framework from its listing, which on a $2,999 machine is the specification most worth asking about before you order.

Notice that speed class and motor rating are separate tests. The FLASH is a 1000W machine limited to 20 MPH, which is Class 2 on speed and above the common nominal cap on power at the same time. Our how to choose an electric bike guide puts this in order against the rest of the decision.

Dual motor is a different question

Two motors is not simply more watts. It is a traction decision, and it deserves separate reasoning.

A single rear hub motor puts all its torque through one contact patch. On loose gravel, sand, snow or a wet steep climb, that patch is the limit — add power and the wheel spins rather than drives. A second driven wheel splits torque across two contact patches and converts more of it into forward motion. That is why the AMYET S8 exists, and why AMYET pairs its 2 × 1000W rated, 3000W peak claim with a 35 degree maximum slope figure. AMYET's folding Ares makes the same 2 × 1000W rated and 3000W peak claim on 24-inch wheels, and EUNORAU's FLASH Lite offers a dual-hub AWD configuration at 52V 1500W with a combined 184 Nm, so two driven wheels is no longer a single-model curiosity here.

It is worth holding the two solutions side by side, because they answer the same question differently. The S8 attacks a steep loose climb with a second driven wheel at $1,049, and the Ares does the same at $1,099. The FLASH attacks it with 220 Nm through eight gears at $2,499. Both work; they cost differently and they fail differently, and only one approach publishes a torque figure — though the FLASH Lite's AWD option now publishes one for the other.

The costs of a second motor are consistent: more weight, more expense, more complexity, and higher consumption when both motors are driving. AMYET's 70 to 75 mile claim on the S8's 1200Wh pack is realistic only under single-motor, low-assist conditions — the reasoning is in why claimed range is never the range you get. Our single vs dual motor guide takes the decision apart properly.