Torque Sensor vs Cadence Sensor

A cadence sensor and a torque sensor answer different questions, and the bike rides like the answer. Cadence asks whether the cranks are turning, then gives the motor the assist level you already picked. Torque asks how hard you are pushing, then scales the motor to that force. Lectric’s 19 August 2026 explainer puts the split in one line each: a cadence sensor helps because you are pedaling; a torque sensor helps according to how hard you are pedaling. Bosch’s help page measures that push in newton-metres and will not hand you the motor’s maximum torque unless you supply a matching pedal force for the mode and its support factor. Watts are a different page — power. This one is the feel. It is not a wiring guide.

What a Cadence Sensor Does

A cadence sensor counts rotation. The usual hardware is a disc of magnets on the crank or the chainring and a hall sensor on the frame a few millimeters away. Each magnet that passes makes a pulse. The controller counts the pulses, decides the cranks are turning, and applies the pedal-assist level already on the display. Grin Technologies describes the early rings: five or six magnets, and you often turned the crank about half a rotation before assist arrived, with a similar lag after you stopped. Twelve poles is the norm now. Twenty-four and higher let the controller notice the turn sooner. More magnets shorten the wait. They do not teach the sensor how hard you pushed.

Basic cadence is close to a step. Pedal, and the motor goes to the power that PAS 1, 3, or 5 was programmed to hold, until you stop or you hit the class speed. Better cadence maps also look at how fast the cranks are spinning. Aventon’s own Sensor Switch note, 11 August 2025, says cadence mode feeds power as soon as the pedals move and bases that power on how fast you spin. Ebike Escape’s May 2026 Level 4 clip makes the same point from the saddle: pedal faster, the motor adds watts; pedal slower, it backs off. That is still not force. A light spin and a hard stomp at the same cadence look the same to the magnet disc.

What a Torque Sensor Does

A torque sensor measures the twist you put into the bike. The common method is a strain gauge on the bottom-bracket axle: the spindle bends a tiny amount, the gauge’s resistance changes, and that voltage is the force. Texas Instruments’ e-bike sensing note describes that axle. Grin’s pedal-assist page lists the other places a system can read the same idea: the chain, the rear dropout, the rear axle, the cogs, or the pedals. Mid-drives from Bosch, Shimano, Brose, and Yamaha hide it in the motor at the bracket. A hub bike can put it in a replacement bottom bracket or at the rear dropout. “Torque sensor” on a hangtag does not tell you which of those you bought.

The controller then multiplies you. Grin’s plain version of the scheme: match the rider watt for watt, or double it, so every watt you put in becomes two from the motor, up to the cap. Bosch calls the multiplier a support factor and ties it to the riding mode. Push gently and the motor stays gentle. Push harder and it adds more, until the mode, the thermal limit, or the class speed says stop. A torque bike is not cadence-blind. Bosch’s same page says torque and cadence are both pieces of power: the same watts show up at a lower pedaling speed if the torque is higher. A cadence number on a fitness screen is a measurement. Aventon’s 14 May 2026 update adds average cadence, rider watts, and rider torque on mid-drive models including the Level 4 ADV and the Current. That readout does not mean the assist law suddenly became a magnet disc.

To call up the maximum torque of the motor, a corresponding pedal force or torque is also required from you. This depends on the riding mode and its support factor.

That sentence is Bosch eBike Systems, not a slogan. It is why a torque bike can feel weak if you only ghost-pedal, and why raising the assist level — the support factor — asks less from your legs for the same motor output. It is also why the maximum newton-metre number on a spec sheet is not a throttle. You have to buy it with the pedal.

Ride Feel

Lectric’s line is the one to keep. Cadence feels like a quick, consistent boost that lets the motor do more of the work. Torque feels like your legs, but stronger. Aventon’s Sensor Switch page says the same thing from the other side: torque is the more natural, more responsive assist, and it is more of a workout, because the motor waits on your pressure. Cadence is the cruise, including for riders who cannot put much force through a pedal.

Neither feel is a moral category. A rider who wants to arrive without sweating will call the cadence step “easy” and the torque bike “slow,” especially in a low support factor. A rider who already likes bicycles will call the same cadence step “a scooter that makes you turn the pedals” and the torque bike “normal.” The how to choose page on this desk already files it that way: torque in traffic if you can get it, cadence if you want cheaper and you can live with a jerk at the lights. The 2026 wrinkle is that “if you can spend it” is no longer a clean price line. The XP4 is a torque-sensor folder at $999.

Starting From a Stop

From a stop, cadence has to see magnets go by. On an old five-magnet ring that could be half a crank of nothing, then a lump of power at whatever PAS you left it on. A 12- or 24-pole ring shortens the nothing. It does not remove the lump. When you stop pedaling, the motor keeps pushing until the controller is sure the pulses have quit. That run-on is why a cadence bike can feel like it is still driving as you coast into a crosswalk.

Torque can start on the push, before a full rotation has been counted, because the force is already in the spindle. The motor builds with your foot instead of arriving as a preset. It can still be abrupt if the support factor is high and you stomp. It is not a throttle. A thumb throttle is a separate Class 2 input that does not ask either sensor anything. On a Class 2 bike the throttle is still capped — 20 mph in the federal shape, often lower on a local sign. The sensor does not move that sign.

Hills

Lectric’s hill paragraph is the honest one. On a cadence bike you do not have to press much harder as the grade gets steeper. The level you selected stays on as long as the cranks turn, so you can climb without becoming a stronger cyclist halfway up. On a torque bike the hill increases your pedal pressure, the sensor reads that pressure, and the motor adds support. You push, it pushes with you. If you cannot push, Bosch’s rule still applies: the motor’s maximum torque stays locked behind a pedal force the mode expects.

Gearing still does more than the sensor. A hub motor has one ratio. When rpm falls on a steep driveway, a cadence hub sitting in a high PAS level can feel stronger than a gentle torque tune you are not loading. A mid-drive multiplies crank torque through the cassette, which is why the same newton-metres climb better in a low gear. The sensor does not see the percent grade. It sees rotation, or it sees your feet. Shift. Then decide which question you wanted the motor to answer.

Technical Riding

Trail bikes that people actually take on roots are torque mids. The Turbo Levo 4 is that shape: a motor at the bracket, a torque reading, and a gear for the punchy bit. You meter the rear wheel by how hard you pedal, which is what you want when a rock asks for a little power and the next one asks for none. A cadence step is a worse tool there. The motor arrives after the magnets, at a level you picked on the fire road, and it can spin the tire or shove the front wheel at the moment you wanted a dab of help.

A fat-hub cadence bike is still a fine gravel path and a poor rock garden. That is motor location plus the sensor, not a dare. This page will not give you a body position, a “feather the pedals” drill, or a parking-lot practice loop. If the trail is the job, buy the torque mid and the gear range. If the trail is a fire road, the sensor argument is smaller than the tires and the brakes.

Commuting

A commute is lights, door zones, and a path with other people on it. Metering beats peak. Torque, or a bike that can be torque when you want it, is the better default in that traffic because the first stroke and the last stroke are under your foot. Cadence is a reasonable commute when the route is flat, the PAS level is one you trust, and you like the motor to carry you. It is a worse commute when PAS 5 is still selected from yesterday and the bike lunges off every curb cut.

Two 2026 commuters already refuse the old binary. Lectric’s 19 August page: the XPress 2 switches between torque-sensing and cadence-sensing in the settings, and the XP Trike 2 750 does the same. The 500W trike stays cadence. Aventon’s Sensor Switch, published 11 August 2025 as an over-the-air update, is a hold of the left arrow on the pad: cadence icon on, torque when the icon is gone. Ebike Escape’s 18 July 2026 brand piece names that switch on the Pace 5 and the Level 4. This desk did not re-flash every serial number. If the bike offers both, use torque in traffic and cadence on the day you are cooked. The class on the hangtag does not change when you do.

Battery Efficiency

There is no percentage. Lectric says it outright: sensor type does not determine range by itself. Terrain, wind, speed, rider and cargo weight, tire pressure, temperature, gear, stops, assist level, and how hard you read the word Turbo all spend the watt-hours. Their next sentence is the one the torque ads skip. A torque-sensor bike ridden aggressively can use more battery than a cadence-sensor bike ridden conservatively.

The mechanism still leans one way if the rider is the same person trying to do the same thing. A high cadence level holds a set power whenever the cranks turn, including a lazy spin on a flat. A torque map drops when you ease off, so the motor is not buying PAS 5 while you soft-pedal to the next light. That is why people say torque “gets more range.” It gets more range when you stop asking. Mash a high support factor up every bridge and the pack does not care what the sensor was called. Buy watt-hours for the route. Then believe a named test, not a sensor adjective.

Cost

A magnet disc and a hall sensor are a cheap part. A strain-gauge bottom bracket, or a mid-drive with the sensor inside it, is not. That is the real cost gap, and it is why the cheapest conversion kits and the cheapest hub bikes are still cadence. It is not a rule you can shop with a single dollar sign in 2026. Lectric’s own list, same 19 August page: XP Lite 2 and the XP Trike 2 500 use cadence; the XP4, XPeak 2, and XPedition 2 use torque; the XPress 2 and the Trike 2 750 switch. The XP4 torque bike starts at $999. The Trike 2 jumps from $1,499 cadence (500W, 624Wh) to $1,799 with the switchable 750W and 840Wh. That $300 is watts, watt-hours, and the sensor. Do not price a torque sensor at $300 off that line.

Dealer mids — Bosch, Shimano, the Levo’s 3.1 — cost what the motor costs. You are not paying a $40 upcharge for a nicer feel. You are paying for the drive unit the sensor lives in, the shop that will touch it, and the support-factor software. If a listing says “pedal assist” and never says torque, assume cadence until the maker’s page says otherwise. “Torque” next to a motor’s newton-metres is the motor’s twist, not proof of a pedal sensor. Read the word sensor.

Reliability

Cadence fails in the open. The disc walks on the crank, a magnet falls out, the sensor gap opens past a few millimeters, a plug backs off, and assist cuts in and out or never comes. You can usually see the fault. The part is external. That does not make it a driveway project for everyone — the gap and the clocking matter — but it is not a motor replacement.

Torque fails inside. A gauge that has taken water, a wire in the spindle, a dropout sensor that no longer returns a clean load, and the assist surges, goes flat, or feels uneven instead of proportional. Replacement is often the bottom bracket or the whole drive unit, which is a shop ticket and a matched part, not a magnet ring from a drawer. E-bike maintenance is the line between a home check and a dealer. This page will not tell you to pull a crank, ohm a gauge, or zip-tie a new disc. A wrong gap is a dead assist. A wrong bracket is a cracked spindle or a fire if someone “fixes” the harness with a random connector. Do that with a technician, or do not do it.

Who Should Choose Each?

Choose cadence if you want the motor to carry you while you turn the pedals lightly, if a hard push is the thing you are trying to avoid, or if the bike you can afford is a basic hub and the route is flat. Lectric still ships that on purpose, on the XP Lite 2 and the 500W trike. It will be jerkier at lights. Set the PAS level like it is a throttle you cannot see, because at a stop it behaves like one.

Choose torque if you want a bicycle that is stronger than you, if you start and stop in traffic, if you climb by pushing rather than by spinning a preset, or if the riding is technical. The XP4, the current Bosch and Shimano mids, and the Levo 4 are that choice. If a torque bike feels like too much work, raise the support factor before you decide the hardware is wrong. Bosch already told you the mode is the multiplier. This desk is not a clinic. Knee pain is a reason to test both, not a reason this page will prescribe a sensor.

Choose a switch if the bike actually has one and you will use it. XPress 2, Trike 2 750, and Aventon’s Sensor Switch where the update is on the bike. Torque for the ride in with cars. Cadence for the ride home when you are done. Do not pay for a switch and then leave PAS 5 in cadence mode for a year.

The sensor does not change the law. Pedals, under 750 W, motor-only under 20 mph is still 15 U.S.C. § 2085. A torque sensor does not make a Sur-Ron a bicycle, and a cadence sensor does not make a 750 W folder legal on a path that bans the class. Buy the feel. Ride the hangtag you actually have.