An e-bike motor sits in one of two places: in a wheel hub, usually the rear, or in the middle of the bike at the pedals, called a mid-drive. A hub motor is simpler and pushes the wheel directly. A mid-drive turns the chain, so it works through the e-bike's gears. Both are legal in Australia when they stay within the power and 25 km/h limits for your state.
This guide covers how each e-bike motor works, what watts and torque figures mean, the power rules, which motor suits hills and everyday riding, and what care each one needs.
By the Ridewave team, updated October 2026
What does an e-bike motor actually do?
It adds to your pedalling. A legal e-bike is still a bicycle: you pedal, and the motor adds its help on top, so hills, headwinds and starts from the lights take less out of your legs.
Three parts work together. The battery stores the energy, a sensor tells the controller you're pedalling, and the motor turns that energy into a push. You choose how much help you get with the assist levels on the handlebar display: a low level for flat paths and saving battery, a higher one for climbs.
Hub motor or mid-drive: what is the difference?
A hub motor drives a wheel directly. A mid-drive motor sits between the pedals and drives the chain, so its help goes through the gears like your own pedalling does.
Hub motors
A hub motor is built into the centre of a wheel. Most are in the rear wheel, which puts the push behind you. Front hub motors exist too, and they pull the e-bike along rather than push it.
The motor works on its own and doesn't rely on the chain or gears. Your gears still matter for your legs, so changing down before you stop and before a climb keeps pedalling comfortable.
Mid-drive motors
A mid-drive motor sits at the crank, where the pedals attach to the frame. It turns the chainring, so the motor's help runs through the chain and gears. Pick a low gear for a climb and the motor gets the same advantage your legs do.
How the two compare
CHOICE's guide to buying an electric bike sets out the trade offs between the two. In short:
| Hub motor | Mid-drive motor | |
|---|---|---|
| Where it sits | In the wheel hub, usually the rear | At the pedals, driving the chain |
| How the help feels | A push at the wheel, separate from the gears | Through the gears, so it climbs with you |
| Traction | Good grip with a rear hub, as the push is at the back wheel | Weight is spread along the bike |
| Cost | Usually costs less to buy and to look after | Usually costs more, and more to replace |
| Chain and gears | Less load on them | Harder on chains, which need to be good quality |
| Tyre changes | Harder at the rear, as the motor is in the wheel | Easier, as the wheels are standard |
| If something fails | A failed motor still lets you pedal home | A snapped chain stops the motor's help too |
What do watts and torque mean on an e-bike motor?
Watts describe the motor's power; torque, in newton metres (Nm), describes its turning force. Torque is the figure you feel when you move off from a stop or start up a hill.
Watts (W). The figure in the rules is continuous rated power, which is what the motor is built to deliver steadily, not its brief peak. That's why legal e-bikes are described as 250W, or 500W in NSW for now.
Torque (Nm). A higher torque figure means a stronger push from a standstill and on a climb. The Miniwave's 250W rear hub motor is rated at 65 Nm, for example. Torque describes the motor's turning force, not the sensor: a motor torque figure says nothing about whether the e-bike has a torque sensor.
Volts (V). You'll also see a battery voltage such as 48V. The voltage and the battery size in amp hours (Ah) tell you about the battery, not how fast the e-bike can go.
How much motor power is legal on an e-bike?
It depends on your state. In both NSW and Queensland, a legal e-bike's motor stops adding power at 25 km/h and only helps while you pedal, apart from a throttle that can help you move off up to 6 km/h.
New South Wales. Transport for NSW says a road legal e-bike has 500W maximum continuous power, falling to 250W from 1 March 2029, a motor that gives no power above 25 km/h, and a throttle-only function that cuts out at 6 km/h. It also says an e-bike that exceeds any of those limits is illegal, even if its power or speed is restricted by an app or switch (Transport for NSW e-bike rules).
Queensland. The Queensland Government says a legal e-bike has a motor of up to 250 watts maximum continuous rated power, gives pedal assistance up to 25 km/h, uses a throttle only up to 6 km/h to help you start, and meets the European standard EN 15194 with a compliance label (Queensland Government e-bike rules). Since 31 August 2026, e-bike riders in Queensland must also be 16 or older and hold at least a learner licence, unless an exemption applies.
Other states and territories. Power limits, footpath rules and age rules differ. Our e-bike laws in Australia guide covers every state, with full pages for NSW and Queensland.
The practical upshot: a bigger motor won't make a legal e-bike faster. If you want more help on hills, look at torque, gears and assist levels, not wattage. For what that 25 km/h limit means on the road, see how fast electric bikes go in Australia.
Which e-bike motor suits hills and your kind of riding?
For most everyday riding, a rear hub motor does the job well. A mid-drive earns its extra cost on long, steep or rough climbs where using the gears matters.
| How you'll mostly ride | What to look for |
|---|---|
| Errands, cafés and short trips on flat or gently rolling paths | A rear hub motor: simple, with less wear on the chain |
| Commuting with traffic lights and stop start riding | A rear hub motor with a good torque figure for moving off, and gears for your legs |
| Hilly suburbs | Check the torque figure and the gear range, and ride a hill on your test ride |
| Long, steep climbs or rough trails | A mid-drive, which uses the gears for the motor too |
| Folding the e-bike into a car or a small flat | A compact e-bike with a removable battery, whichever motor it has |
On hills, technique counts on either type. Change down before the climb rather than halfway up, choose a higher assist level, and keep pedalling smoothly.
Does the motor or the sensor shape how an e-bike feels?
Both do. The motor decides how much push you can get; the pedal assist sensor decides when that push arrives and how closely it follows your pedalling.
A cadence sensor responds to the pedals turning. A torque sensor responds to how hard you press. Either can be paired with a hub motor or a mid-drive, so the sensor is a separate question from the motor. Our guide to torque and cadence sensors explains how each one feels to ride.
When people take a first ride at our showrooms, the thing they notice first is how smooth the pedal assist feels. That's why a test ride tells you more about an e-bike motor than a spec sheet does.
What care does an e-bike motor need?
Very little on the motor itself. Most of the care goes to the parts around it: the chain, the gears, the connectors and the battery.
- Keep the chain clean and lubed. On a mid-drive, the chain carries the motor's help as well as yours, so it works harder. Our e-bike chain cleaning guide goes step by step.
- Keep water off the electrics. Skip the pressure washer around the motor, connectors and battery.
- Check the cables and plugs. A loose or damaged connector can cut the motor out. If the motor stops, stutters or the display shows an error, get it checked before you ride on.
- Take care with rear wheel jobs on a hub motor. The motor cable runs into the wheel, so removing the rear wheel for a puncture takes a few more steps. If you're not sure, ask a mechanic.
For a full routine, see our e-bike maintenance schedule.
Which Ridewave e-bike should you try?
If a rear hub motor suits the way you ride, try the Miniwave folding e-bike. It has a 250W rear hub motor rated at 65 Nm, Shimano Altus 8 speed gearing to pair with it on hills, and hydraulic disc brakes with 180 mm rotors front and rear. It also has a start-up throttle that helps you move off from a stop, up to 6 km/h.
The Miniwave is certified to EN 15194 and holds a NSW certificate of approval. Its removable 48V battery comes in two sizes, with a range of up to 110 km (10.4Ah) or up to 140 km (13.2Ah) at pedal assist level 1 on a flat road. It folds in three steps to 98 x 52 x 73 cm, for the car or a small flat.
If you'd rather ride on three wheels, see the electric trike collection.
What a hub motor can't do
A rear hub motor isn't the right fit for every rider. If most of your riding is long, steep climbs or rough trails, a mid-drive that works through the gears will suit you better than the Miniwave's hub motor. No motor can make a legal e-bike go faster than 25 km/h under power, so if speed is the goal, an e-bike isn't the answer.
Frequently asked questions
Can I upgrade or swap my e-bike motor?
On a road legal e-bike, think twice. The Queensland Government says after-market conversion kits are not compliant with EN 15194 and make the device illegal to ride in public, and Transport for NSW says hacking or tampering with an e-bike may make it illegal. If a motor fails, have it repaired or replaced like for like.
Is a 500W e-bike legal?
In NSW, an e-bike with up to 500W maximum continuous power is legal for now, falling to 250W from 1 March 2029. In Queensland the limit is 250W. Check our state by state rules for where you ride.
Feel the difference in person
The easiest way to feel how a rear hub motor helps on a start or a slope is to ride one.
Test rides run at our showrooms in Vermont (Melbourne), Girraween and Marrickville (Sydney). Most visits take 30 minutes to an hour, and you're welcome to bring someone along. Call ahead so we can have the right model ready for you: book a showroom test ride, or call us on +61 468 095 888.
Sources
- E-bikes, Transport for NSW, checked October 2026
- E-bike rules in Queensland, Queensland Government, checked October 2026
- Electric bike buying guide, CHOICE, checked October 2026
Related articles
- Torque vs cadence sensors on e-bikes explained: the other half of how an e-bike's help feels.
- How fast do electric bikes go in Australia?: the 25 km/h rule and what it means on the road.
- E-bike maintenance schedule: what to check before each ride, weekly, monthly and yearly.