A torque sensor measures how hard you push on the pedals and scales the motor’s power to match your effort, while a cadence sensor only detects whether — and how fast — the cranks are turning, then delivers a preset level of assist. Put simply: a torque sensor feels natural and athletic (push harder, get more power), and a cadence sensor feels like a smooth, steady boost that switches on the instant you start pedalling. Neither is objectively better — the right one depends entirely on how, and where, you ride.
This is the question we field more than almost any other on the floor at Cyberbikes in Leichhardt, so let’s settle it with real engineering rather than marketing. If you want the wider picture first, our guide to how e-bikes actually work — motors, sensors and controllers sets the scene; this post zooms in on the two sensors that decide how your e-bike feels.
What a cadence sensor actually does
A cadence sensor — Grin Technologies, the engineers behind the Cycle Analyst, call it a “basic PAS sensor” — is the most common assist sensor on affordable e-bikes. It’s typically a ring of magnets on the crank or bottom bracket paired with a fixed pickup that counts each magnet as the pedals spin. From that, the controller learns exactly one thing: are you pedalling, and roughly how fast? It has no idea how much force you’re applying.
Because of that, a cadence system usually delivers a set amount of power whenever it sees the cranks moving. Select assist level 3 and you get level-3 power whether you’re spinning gently on the flat or grinding up a climb. You manage the bike with the handlebar assist buttons rather than with your legs — a bit like setting cruise control.
The spec that matters most here is the number of magnetic poles on the ring. Early sensors had just 5–6 magnets, so you’d turn the cranks nearly half a revolution before the motor woke up, with a matching delay before it cut out. Modern sensors use 12 poles as standard, and 24-pole (or higher) units give noticeably snappier pickup. As Grin’s own pedal-assist reference explains, more poles means faster response and less of that “pause, then lurch” sensation off the line.
What a torque sensor actually does
A torque sensor measures the real force you put into the pedals and tells the motor to amplify it. This is usually described as a multiplier: at a 1:1 setting every watt from your legs is matched by a watt from the motor; at 2:1, each of your watts is doubled. Pedal harder and power climbs instantly; ease off and it fades — no buttons required.
Here’s the engineering worth carrying with you: your actual pedalling power is torque multiplied by cadence (watts = torque × rpm). A genuine torque-sensing system reads both the force and the crank speed, which is also why it can display your human power output in watts — something a cadence-only bike simply cannot do.
“Torque sensor” is really an umbrella term. Grin documents at least eight ways to sense rider effort: bottom-bracket spindle torque, chainring torque, chain tension, rear-dropout force, and rear-axle flex (the method the old BionX system pioneered), among others. Bottom-bracket sensors are the most common on aftermarket conversions; purpose-built factory e-bikes often hide the sensor in the dropout or the hub.
Torque vs cadence: how each one feels to ride
The difference is obvious the first time you swap between them. Here’s the honest side-by-side we give customers:
| Feature | Cadence (basic PAS) sensor | Torque sensor |
|---|---|---|
| What it senses | Crank rotation only | Pedal force + rotation |
| Ride feel | Steady, scooter-like boost | Natural — amplifies your effort |
| Response off the line | Slight lag (depends on poles) | Near-instant |
| Best for | Relaxed cruising, stop-start city | Fitness, hills, “earned” power |
| Shows your power in watts | No | Yes |
| Typical cost | Lower | Higher |
The signals and safety hiding inside the sensor
Under the covers, these sensors speak in low-voltage electrical signals, and the details matter for both feel and safety. A basic cadence sensor outputs digital 0–5V pulses; a torque sensor adds an analog voltage that rises or falls with pedal force (brands scale it differently — some rest at 2.5V and drop under load, others climb from around 1.5V upward).
One clever safety detail: the sensor has to tell the difference between pedalling forwards and rolling the bike backwards out of a rack — otherwise the motor could surge unexpectedly. Better sensors, including most of Grin’s, use a two-wire “quadrature” signal so the controller can read pedal direction from the order of the pulses. And crucially, a proper torque sensor always pairs its force reading with a cadence reading: if a bike could drive off the torque signal alone, a drifting sensor could make it lurch with no pedalling at all, so the cranks must actually be turning before power is applied.
Which sensor is better for Sydney riding?
It genuinely depends on your ride. A torque sensor couples motor power to your effort, so your workload rises and falls with the terrain — you’ll work harder up the Iron Cove and Inner West climbs and coast easily on the flats, much like a regular bike with a superpower. If you ride for fitness or love that connected feel, it’s hard to beat.
A cadence sensor decouples effort from terrain. Set your assist level and the motor makes up the difference, so you can hold a relaxed, steady pace whether climbing or cruising — ideal for stop-start commuting through Leichhardt, and arriving without a sweat. For nudging along in busy traffic, that predictable, button-controlled boost is often the more relaxing choice.
Whichever sensor a bike uses, NSW law is the same: a road-legal pedal-assist e-bike (a pedalec) is capped at 250W of continuous motor power and must cut assist at 25 km/h. The Cyberbikes Centauro is built to that standard — a 250W rear hub motor, a UL 2271-certified 48V 25Ah (1200Wh) Samsung battery, hydraulic brakes and a 150kg load rating, priced at $3,999.99 and fully NSW-compliant.
Does a torque sensor give better range?
Usually, yes — modestly. Because a torque sensor only adds power in proportion to your effort, it tends to draw less from the battery than a cadence system delivering full preset power every time the cranks move. A well-set-up pedal-assist system also generally beats riding on throttle alone for range. Even so, your riding style, tyre pressure and the hills matter far more than the sensor.
Can I have a throttle and a pedal-assist sensor together?
On many systems, yes. Plenty of e-bikes pair a cadence sensor for relaxed assist with a throttle for instant power from a standstill or across an intersection. Just remember that NSW throttle rules differ from pedal-assist rules, so check exactly how a bike is configured before you buy — or ask us and we’ll explain what’s road-legal.
See it in action
Power delivery, gears and pedalling all interact — here’s a quick look from our Sydney workshop at what happens when a Bafang mid-drive meets a badly timed gear shift:
Frequently asked questions
Is a torque sensor worth the extra money?
If you value a natural, responsive ride and want to feel connected to the bike, yes. If you mainly want effortless, predictable assist for commuting, a good 12- or 24-pole cadence sensor does the job for less. Test-riding both is the only reliable way to know which you prefer.
Does a torque sensor improve e-bike range?
Generally a little, because it delivers power in proportion to your effort rather than a fixed level, so it can sip less battery on easy sections. Real-world range depends far more on terrain, rider weight, tyre pressure and assist level.
How can I tell if an e-bike has a torque or cadence sensor?
Ride it. A torque sensor responds the instant you press harder and eases off when you relax; a cadence sensor gives a steady, set level of power a fraction of a second after you start spinning, regardless of how hard you push. If in doubt, ask us at Cyberbikes and we’ll show you the difference on the spot.
No spec sheet can tell you which sensor you’ll love — your legs decide that in the first thirty seconds. Come in for a test ride at Cyberbikes, 281 Parramatta Road, Leichhardt, and feel the difference between torque and cadence for yourself. Browse the Cyberbikes Centauro or call us on 0491 794 668, Tuesday–Saturday.
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