A cadence sensor switches your e-bike’s motor on based on how fast you spin the pedals, while a torque sensor measures how hard you push and scales the assist to match your effort. That one difference changes everything about how the bike feels. A cadence-sensor e-bike delivers a steady, almost throttle-like boost the moment the cranks turn; a torque-sensor e-bike amplifies your own pedalling so the ride feels natural and connected. Neither is universally “better” — the right choice depends on how and where you ride. Below we break down exactly how each system works, what the engineering actually does under you, and which one suits Sydney commuting, drawing on the pedal-assist research from Grin Technologies (ebikes.ca).
What is pedal assist, and how does a sensor decide when to help?
Pedal Assist System (PAS) is the general term for any setup that powers the motor automatically when you pedal, without you touching a throttle. Bikes that behave this way are often called pedelecs. According to ebikes.ca, pedal-assist sensors fall into two broad families: basic (cadence) sensors, which detect only the speed at which the cranks are turning, and torque sensors, which additionally measure how much force the rider is applying to the pedals. Everything about the ride feel — smoothness, responsiveness, how much you “earn” the power — flows from which of those two the bike uses.
How a cadence sensor works
A cadence sensor is the simpler, more common type. Most versions use a ring of magnets attached to the crank arm or spindle, with a pickup that counts the magnets passing as you pedal. The controller therefore knows how fast you are spinning the cranks, but it has no idea how hard you are pushing. In its most basic form it simply applies a set amount of power whenever it detects the pedals moving.
The key engineering variable is the number of magnetic poles on the ring. ebikes.ca notes that early sensors had just 5 or 6 magnets, so you had to turn the cranks roughly half a rotation before the motor woke up — and there was a matching lag before the power cut out when you stopped. Today 12 poles is the norm, and 24-pole (and higher) sensors are increasingly common, giving much faster, more immediate pedal response. Cadence sensors are also direction-aware, so rolling the bike backwards out of a rack doesn’t trigger a surprise burst of power.
How it feels to ride: the assist arrives quickly and stays consistent regardless of the hill, and you dial the power up or down from a handlebar button. That makes a cadence e-bike feel a bit like a throttle you don’t have to hold — the motor covers the terrain so your effort can stay comfortable and even, whether you’re climbing or cruising.
How a torque sensor works — and what “1:1” or “2:1” assist means
A torque sensor measures the actual force you put into the pedals. Most aftermarket versions are a replacement bottom bracket with force sensing built in, though ebikes.ca lists other methods that read the chain tension, rear dropout, rear axle flex or the chainring. The motor power is then dialled in to amplify your pedal effort, usually expressed as a multiplier: a 1:1 setting matches your output watt-for-watt, while a 2:1 setting adds two motor watts for every watt your legs produce. Pedal harder and you get more power; ease off and the motor backs off with you.
This is why torque-sensor bikes feel so natural — ebikes.ca describes it as an almost “bionic” connection between your legs and the bike. It also means the ride mirrors a normal bicycle: you work harder going uphill and the effort eases on the flat. As a bonus, because the system already measures your force, a torque sensor paired with a good display can read out your own human power in watts.
Why a torque sensor still needs a cadence signal
Here’s a detail most riders never hear: torque sensors carry both a torque signal and a cadence signal. There are two reasons. First, your real power output is torque multiplied by pedal RPM, so the system needs both numbers to know how many watts you’re actually contributing. Second, it’s a safety measure — ebikes.ca warns that if a bike could be driven from the torque signal alone, with no confirmation that the cranks are rotating, a sensor drift or setup error could make the bike take off on its own. On the wiring side, the cadence signal is a digital 0–5V pulse while the torque reading is an analog 0–5V voltage, which is why the two sensor types are not directly interchangeable between systems.
Torque sensor vs cadence sensor: which feels better?
It genuinely depends on the rider. A torque sensor couples the motor to your effort, so the terrain is something you feel — great if you want the exercise and a bike-like connection. A cadence sensor decouples the two, letting the motor flatten the hills so your effort stays constant — great for arriving un-sweaty or for stop-start city traffic where you don’t want the motor surging every time the pedals nudge forward. Here’s the quick comparison:
| Feature | Cadence sensor | Torque sensor |
|---|---|---|
| Measures | How fast you spin the cranks | How hard you push the pedals |
| Power delivery | Set/steady boost per assist level | Proportional to your effort (e.g. 1:1, 2:1) |
| Ride feel | Throttle-like, consistent, effortless | Natural, “bionic”, bike-like |
| Best for | Commuting, stop-go traffic, easy constant effort | Fitness, hills you want to feel, precise control |
| Typical cost | Lower | Higher |
If you’re weighing this alongside the bigger drivetrain picture, our guide to how e-bike motors are built and mounted covers where the motor sits, and our explainer on where your battery’s energy actually goes shows why efficient power delivery matters just as much as the sensor.
What this means for Sydney riders and the Cyberbikes Centauro
In New South Wales, a legal pedal-assist e-bike (a pedelec) is limited to 250W of continuous motor power and must cut its assistance once you reach 25 km/h; the separate throttle-only category is capped at 200W. Crucially, both sensor types operate happily inside those limits — the sensor changes how the assistance feels, not whether the bike is road-legal. So the question for a Sydney rider isn’t “which is legal”, it’s “which feel do I want on my commute?”
The Cyberbikes Centauro pairs a 250W rear hub motor with a 48V 25Ah (1200Wh) Samsung battery, a UL 2271-certified battery pack, an ISO 4210-compliant 6061 aluminium frame, four-piston hydraulic brakes and a 150kg load rating — a lot of practical e-bike for $3,999. But specs only tell you so much about pedal-assist feel. The only real way to know whether a steady cadence-style boost or a proportional torque-style push suits you is to ride both, which is exactly what we set up in-store at Cyberbikes Leichhardt.
See a Cyberbikes e-bike in action
Here’s a quick look at the Centauro — the everyday e-bike Sydney riders come in to test the assist on:
Frequently Asked Questions
Is a torque sensor always better than a cadence sensor?
No. A torque sensor feels more natural because it scales power to your effort, but a cadence sensor is better if you want a steady, effortless boost that stays constant regardless of terrain — for example on a stop-start city commute. According to ebikes.ca, riders who prefer to regulate motor power independently from their pedal effort are actually better served by a good cadence (basic PAS) setup.
Can you tell which sensor an e-bike has just by riding it?
Usually yes. On a torque-sensor bike the power rises and falls smoothly with how hard you push, so pedalling harder immediately gives more motor. On a cadence-sensor bike the assist tends to arrive as a steady level as soon as the cranks turn and doesn’t change much when you push harder at the same speed — you adjust it from the handlebar instead.
Does a torque sensor give you more range?
Often, but indirectly. Because a torque sensor only adds power in proportion to your effort, it tends to draw less battery during gentle riding than a cadence system that applies a fixed boost whenever the pedals move. Your actual range still depends far more on the battery’s watt-hours, the terrain, rider weight and how much assist you choose.
Come in for a test ride at Cyberbikes, 281 Parramatta Road, Leichhardt and feel the difference between a torque and cadence sensor for yourself — or browse the Centauro e-bike online. Ask us about rent-to-own plans from $99.99/week.
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