Electric scooter motors: geared hub vs direct-drive hub

“250 W motor” on an electric scooter spec sheet is just a number. Behind it sits a specific architecture that determines whether your scooter will be quiet, whether it will recover energy, whether it will pull up a hill and how much it will actually weigh. This article covers the three main drivetrain configurations found in modern electric scooters: chain drive (historical, kids’ category), the geared hub motor with a planetary reducer (geared hub), and the direct-drive hub motor (direct-drive / gearless hub), on which the overwhelming majority of adult electric scooters today are built — from the Xiaomi M365 to the NAMI Burn-E.

First: BLDC instead of brushed

Almost every modern electric scooter is driven by a brushless DC motor (BLDC). This is a distinct technology that displaced the older brushed DC motors. In a brushed motor, graphite brushes physically rub against the commutator to transmit current to the rotor windings — they wear out, spark and produce heat; efficiency is usually 70–80 %. In a BLDC motor the windings sit on the stator and the rotor is permanent magnets; current in the winding phases is switched by an electronic controller that reads rotor position from Hall sensors (sensored controller) or, less commonly, from the motor’s own back-EMF (sensorless). Per OEM surveys, modern BLDC hub motors hold a steady 85–90 % efficiency, have no rubbing parts and last thousands of hours. A sensored controller is needed because at a standing start a sensorless setup does not know the rotor position and can jerk, especially uphill. (Dewesoft — Optimizing BLDC motor efficiency in e-scooters, Greensky Power — OEM’s Guide to BLDC for E-Scooters, Upbeat Geek — Sensored vs sensorless BLDC controllers)

The controller as a separate module (six-step vs sine-wave/FOC, MOSFET set, sensored vs sensorless) is covered in the article on electronics; here we focus on the motor itself.

Architecturally, a BLDC can be mounted next to the wheel and transmit torque through a chain or belt (as in the kids’ Razor E100) or integrated directly into the wheel hub as a “hub motor”. A hub motor, in turn, can be either geared or direct-drive. From this come the three configurations listed below.

1. Chain drive (Razor E100 and the kick-scooter kids’ niche)

This is the oldest and, today, almost exclusively a kids’ configuration. A separate motor is attached to the frame next to the rear wheel and turns it through a chain or toothed belt. In the canonical example — the Razor E100 (since 2003) — this is a 24 V brushed DC motor of 100 W with a 9-tooth sprocket and a #25 chain. The motor housing is about 100 × 68 mm, mass ~3 kg. Razor themselves write: “100-watt high-torque single-speed chain-driven motor”. (Razor — E100 specs, Amazon — Razor E100 100 W chain-drive motor (MY6812), MotoTec — Electric motor 24V 100W for Razor E100/E125/E150)

Why this scheme has remained only in the kids’ niche:

• Transmission losses. The chain costs several efficiency points and requires tensioning, lubrication and replacement. A hub motor does without all of this.
• Size and mass. An external motor “eats” space next to the frame, making it harder to build a foldable, compact wheel.
• Noise. A metal chain is louder than a quiet BLDC hub.
• The ASTM F2641 standard (covered in the article on scooter types) for kids’ models allows low-power brushed DC motors: price matters more than efficiency, because a child does not ride tens of kilometres a day. That is why Razor still fits a simpler, cheaper brushed motor with a chain.

In the adult category, chain drive is found only in some retro scooters and home-brew conversions. Integrating the motor into the wheel has become the standard.

2. Geared hub motor

This is a BLDC motor inside the wheel hub with a planetary reducer. A small high-speed rotor in the centre spins 4–5 times faster than the wheel itself; between them sits a planetary gear train (a sun gear plus three planets) that lowers the rpm and, by the same ratio, multiplies the torque. A typical reducer ratio is 5:1: the motor makes five turns per one wheel turn and delivers five times the torque it would have produced directly. (Hentach — Hub motor gears explained, Marsantsx — Planetary gears in hub motors)

Strengths:

• High torque at low rpm — pulls away from a standstill, climbs hills and feels confident in stop-and-go traffic.
• Smaller size and lower mass. At the same output power a geared hub is 30–50 % lighter than a comparable direct-drive, because the motor itself can be smaller (its job is to spin fast, not strong). (Levy Electric — Hub motor mechanics)
• Freewheel. Most geared hubs put an overrunning clutch between motor and wheel: when the throttle is released, the wheel spins freely and does not drag the magnets and gears with it. There is no “cogging” (the magnetic drag from the stator that passively brakes the wheel).

Weaknesses:

• No regenerative braking. That same overrunning clutch which gives the freewheel mechanically disengages the motor from the wheel when the throttle is released — so the motor cannot brake the wheel or charge the battery. Both the e-bike and e-scooter industries confirm this. (Fluid Free Ride — Electric scooter motors guide, Electric Bike Report — Direct drive vs geared hub motors)
• Gear-mesh noise. Plastic or metal planets produce a characteristic “whirr” of 50–60 dB — quieter than conversation, but noticeably louder than a direct-drive hub. (Hentach — Geared hub vs direct drive)
• Gear wear. Nylon gears with reinforcement last thousands of kilometres, but this is still a service item — unlike a direct-drive hub, where there is essentially nothing to wear.

Where you find this in electric scooters. In the e-bike world, geared hubs dominate the moped and cargo categories. In electric scooters, geared hubs today are mostly cheap, ultra-light or high-torque off-road models. One reason is that an e-scooter rides in a cruise mode of 20–40 km/h, where a direct-drive hub is more efficient; and intense standing starts, where a geared hub shines, are not as critical as on a pedal-equipped bicycle. A recent attempt to address the geared hub’s main shortcoming came from Grin Technologies: in 2019 it introduced the GMAC — a geared hub without a clutch, capable of regen precisely because there is no freewheel. In production electric scooters such a scheme is still rare. (Electrek — Grin GMAC clutchless geared hub with regen)

3. Direct-drive hub motor (gearless)

This is the dominant configuration in modern adult electric scooters: from the 250-watt Xiaomi M365 to the 8.4-kilowatt NAMI Burn-E 2 Max. A direct-drive BLDC hub is, in effect, “an inside-out motor in the wheel”: the axle is stationary and holds the stator with copper windings, while the rotor with permanent magnets is the wheel shell itself. The electronic controller energises the winding phases in turn; the magnetic field pushes the magnets, and the wheel spins. There are no gears. (Fluid Free Ride — Electric scooter motors guide, Levy Electric — Hub motor mechanics, Unagi — What is a BLDC motor on an electric scooter)

Strengths:

• Regenerative braking (KERS). Because the motor is always rigidly coupled to the wheel, the controller can “flip” the motor’s role — make the magnets-in-the-wheel induce current into the stator. That current charges the battery while simultaneously braking the wheel. A classic example is the Xiaomi M365: a soft press on the brake lever engages KERS in the front hub motor (3 levels in the Mi Home / Ninebot app — Weak / Medium / Strong), and a harder press adds the mechanical rear disc brake. (Wikipedia — Xiaomi M365, eBike Choices — Xiaomi M365 regen braking)
• Quiet running. Without gears the motor only hums at the electromagnetic switching frequencies — 40–45 dB, quieter than conversation. This is one reason sharing operators (Lime, Bird, Dott) fit direct-drive: night riding in residential areas does not annoy people. (Hentach — Geared vs direct drive)
• Simplicity and reliability. There is nothing to wear: the axle bearings, the stator windings and the rotor magnets. E-bike manufacturers cite service intervals of >20 000 miles — for fleet-rotated sharing scooters (Bird Three, Lime Gen 4) this longevity is critical.
• High efficiency at cruising speed. In steady-state riding at 25–40 km/h a direct-drive hub returns 88–90 % efficiency, because there are no reducer losses.

Weaknesses:

• Lower torque at low rpm. Without a reducer the motor has to pull “with its own muscle”; from a standstill and on a steep hill a direct-drive hub is noticeably slower than a comparable geared one. Manufacturers compensate with significantly higher nominal power (350–1 500 W instead of 250 W) and dual-motor configurations — see below.
• “Cogging” (magnetic drag). Magnets always pass by the iron stator teeth, creating a weak braking effect even when the motor is off. On the wheel this feels like a faint “pull-and-release”, and on a descent it reduces coast distance.
• Mass and bulk. A direct-drive hub is heavier than a geared hub at the same nominal power. On small 8.5–10″ wheels this is not critical, but on powerful models (NAMI, Dualtron) each rear motor wheel weighs 8–12 kg.

Market examples (all direct-drive BLDC hubs)

• Xiaomi M365 / Mi 4 — front motor wheel 250 W nominal / 500 W peak, ~16 N·m of torque, 36 V. Three levels of KERS regen. (Voltride — E-scooter motors catalogue, Wikipedia — Xiaomi M365)
• Segway-Ninebot KickScooter MAX G30 — rear motor wheel 350 W nominal, with IPX7 rating on the motor itself. Sensored controller, regenerative brake. (Segway — MAX G30LP specs)
• INOKIM Light 2 — rear 350 W nominal / 650 W peak, 15 N·m, gearless BLDC, 13.5 kg total scooter mass. (Rider Guide — Inokim Light 2 review, Electrek — Inokim Light 2 review)
• Apollo City / City Pro — dual-motor 2 × 500 W BLDC hubs in the front and rear wheels, combined peak 2 000 W, independent control of front and rear motors. (Apollo Scooters — City 2024 dual-motor tech specs, Electric Scooter Insider — Apollo City Pro review)
• Dualtron Thunder 3 — 2 × 1 500 W BLDC hubs in tubeless 11″ wheels, peak combined output up to 11 000 W, 72 V × 40 Ah LG pack. (Dualtron USA — Thunder 3, NYC PEV — Dualtron Thunder spec sheet)
• NAMI Burn-E 2 / Burn-E 2 Max — 2 × 1 000 W (Burn-E 2) with a 5 000 W peak, or 2 × 1 500 W (Burn-E 2 Max) with an 8 400 W peak; 50-amp sinewave controllers with front-rear torque-balance tuning across 5 modes. (Fluid Free Ride — NAMI Burn-E 2, Hyper Rides — NAMI Burn-E 2 Max, Rider Guide — NAMI Burn-E 2 Max review)

How to read the “motor” line in a spec

Manufacturers are generous with big numbers, but it pays to know what each figure refers to:

• Nominal (continuous) power — what the motor delivers in sustained operation without overheating. This is the figure regulators care about (eKFV: ≤ 500 W; Ukraine PLET: ≤ 1 000 W — see regulation in 2010–2020 and 2020–2026).
• Peak (max) power — a brief maximum: standing start, overtake, hill. Usually 2–5× the nominal. Do not confuse with nominal in a legal context.
• Torque (N·m) — a more realistic “pull” metric than watts. Most manufacturers do not publish it; when they do, the normal consumer range is 15–50 N·m per wheel, in performance models — 80+.
• Sensored vs sensorless controller — sensored, with Hall sensors, starts smoothly from zero; sensorless is cheaper and lighter, but may jerk at start. For an adult urban scooter this is almost always sensored.
• Sinewave vs square-wave controller — sinewave delivers smoother current into the phases, a quieter motor and lower heating losses; square-wave is cheaper and simpler. Most modern performance models (NAMI, Dualtron, Apollo Pro) explicitly state sinewave.
• Single vs dual motor — dual-motor models carry two BLDC hubs, one in each wheel, with independent control. This gives all-wheel drive (AWD), a better launch, the ability to ride on one motor to save charge, and a higher peak power — at the cost of mass, price, and the fact that such machines fall outside the legal limits of urban-legal consumer classes.

Summary

The next chapters of this guide cover batteries (what real range depends on), brakes (disc, drum, electronic, foot) and suspension and wheels (pneumatic vs solid, IP protection). The motor sets the upper bound of what a scooter can do; the rest of the running gear decides whether it does it safely.