An electric bike’s cadence sensor is key to smooth pedal assist.
When it fails or goes out of alignment, your e-bike can suddenly feel like a regular bike – no boost, just your own muscle power.
This can be frustrating if you’re used to effortless hill climbs and speedy commutes. The good news is that most cadence sensor issues can be fixed with some basic DIY troubleshooting, restoring your e-bike’s pedal assist and getting you back to enjoying the ride.
A frustrated rider experiencing pedal assist failure – diagnosing the cadence sensor can often resolve sudden loss of motor help.
Quick Summary of Cadence Sensor Troubleshooting
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Check basic issues first: Ensure the battery is charged and the pedal assist mode is on (not set to zero). If your ebike has a throttle, test if it still works; a working throttle but no pedal assist usually points to a pedal assist sensor problem. Also verify that no error codes are showing on the display.
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Inspect brake cut-off sensors: A common oversight is brake lever sensors stuck in the engaged position, which will silence the motor. Make sure both brake levers fully release and that their sensors aren’t falsely signaling a brake pull (a misaligned brake sensor can prevent pedal assist from engaging).
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Verify sensor & magnet alignment: The cadence sensor (usually near the crank) must sit very close to the magnet disc. If the magnet ring has slid away or gotten knocked out of position, the sensor can’t detect pedaling. Adjust the magnet ring to about a 1–3 mm gap from the sensor for reliable operation. This simple fix of repositioning the magnet disc against the sensor resolves most pedal assist issues.
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Keep it clean: Dirt or debris on the sensor or magnets can block the signal. Wipe the sensor and magnet ring with a damp cloth to remove any mud or grime. Cleanliness is paramount – even a thin layer of dirt can interfere with detection.
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Check wiring connections: Examine the sensor’s cable for damage or loose plugs. Unplug and reconnect the PAS sensor connector to ensure a snug fit, and look for frayed wires or corrosion. A poor connection can stop the sensor signal from reaching the controller.
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Test the sensor’s indicator (if available): Many cadence sensors have a small red LED that lights up when the sensor has power and blinks as magnets pass. Pedal the bike and watch this light. If it never lights or blinks, the sensor may not be receiving power or is faulty. In that case, double-check the wiring; if wiring is fine, consider replacing the sensor.
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Repair or replace as needed: If alignment and cleaning don’t help and the sensor still doesn’t register pedal movement, the unit could be defective. External cadence sensor kits are generally inexpensive and easy to swap out – simply unplug the old sensor and plug in a new one. If a new sensor doesn’t fix the issue, the problem likely lies with the controller, and further diagnostics or professional help may be needed.
Related: Best Pedal Assist Electric Bike of 2025
Understanding Cadence Sensors and Pedal Assist
To troubleshoot effectively, it helps to know what the cadence sensor does.
In an electric bike’s pedal assist system, a cadence sensor is a simple device that detects when and how fast you are pedaling.
It typically consists of a magnet ring attached to the crank, and a sensor (with a small electronic hall effect switch) mounted on the bike frame near that ring.
As you pedal, magnets pass by the sensor, triggering it to send signals to the controller. If the controller sees the pedals moving, it activates the motor to provide assistance.
Cadence-based pedal assist is essentially an on/off system – if you are pedaling, the motor can engage (according to the assist level set), and if you stop pedaling, the motor stops.
This is different from a torque sensor, which measures how hard you press on the pedals.
A torque sensor provides proportional assist based on pedal force, whereas the cadence sensor cares only that you are pedaling and at roughly what cadence.
Cadence sensors are common on many e-bikes because they’re simple and reliable, but they do require proper alignment to work correctly.
One critical component is the magnet disc (or magnet ring). It’s usually a plastic ring with multiple embedded magnets, mounted on the pedal crank or bottom bracket spindle.
The cadence sensor must face this magnet ring with only a small gap in between. Typically, a gap of a few millimeters (around ~3 mm) is recommended – close enough for the sensor to detect magnets, but not rubbing.
If this gap becomes too large or the alignment is off, the sensor won’t register your pedaling. Understanding this physical setup is important: many “sensor problems” are simply due to the sensor and magnet being out of position.
The cadence sensor is part of the overall Pedal Assist System (PAS).
When functioning properly, you barely notice it – you pedal and the bike smoothly amplifies your effort. But when something’s wrong, the bike might not respond at all to your pedaling.
In the next sections, we’ll look at how to identify those issues and fix them.
Common Cadence Sensor Issues & Symptoms
How do you know if your e-bike’s cadence sensor is the culprit behind a loss of pedal assist? Here are some common problems and telltale symptoms:
No Assist Activation at All
You pedal, but the motor doesn’t kick in. The bike behaves like a normal bicycle with no power.
This is a classic sign the PAS sensor isn’t detecting pedal movement.
If your display shows you’re in an assist level and the motor still doesn’t respond, the cadence sensor or its connection might be at fault.
Intermittent or Cutting Out
The motor sometimes helps and sometimes doesn’t, or it starts to assist then suddenly stops even though you’re still pedaling.
This jerky, unpredictable assist can indicate a loose sensor connection or misaligned sensor – for example, the magnet ring might be wobbling, or a wire is intermittently disconnecting.
Delayed Engagement
There is always a small natural delay with cadence sensors (since the bike waits for a pedal rotation or two), but if you notice an unusually long lag before assist kicks in, it could mean the sensor is barely picking up the signal.
A sensor positioned too far from the magnet ring or a weak magnet signal might cause this behavior.
No Error Code on Display
In many cases, a failing cadence sensor does not trigger an error message.
The bike simply doesn’t assist. For instance, you might not see any error code while the bike refuses to go into assist mode.
This can make it tricky, because everything looks “normal” except the motor isn’t helping. (Some e-bikes might show a general error like “PAS error” or “speed sensor error,” but many just have no assist with no code.)
These symptoms often point to the cadence sensor because other issues tend to show different signs. For example, if the battery was the problem, your display might flicker or the bike might lose all power, not just pedal assist.
If the motor or controller failed, the throttle (if you have one) would likely not work either. But when only pedal assist is non-functional, the cadence sensor and its related parts are the prime suspects.
RELATED: Electric Bike Pedal Assist vs. Throttle Mode
Why Cadence Sensors Fail (or “Go Missing”)
Knowing the common causes of cadence sensor issues will help us fix them. The most frequent causes include:
Misalignment or Gap Issues
By far the number one cause. The sensor and magnet ring can shift out of alignment due to bumps, vibrations, or after maintenance work on the crank.
If the magnet disc slips away on the axle or is knocked sideways, the sensor may no longer register each rotation. Even a gap of just a few extra millimeters can render the sensor “blind” to your pedaling.
It’s common, for example, for a magnet ring to slide outward on the crank spindle over time – especially if a loose chain or something bumped it (some riders have found a loose chain can push the ring out of place during riding) causing the sensor to stop detecting.
Physical Damage
The sensor itself or the magnet ring can be damaged. The sensor is usually a small plastic piece – it can crack or its mounting can loosen (e.g., if a stick hits it or the bike falls over).
The magnet disc can also crack or lose magnets, though that’s rarer. Any damage to these parts can disrupt the sensor’s ability to pick up pedal motion.
Wiring Problems
The cadence sensor has a cable that runs to the controller. If this cable is pinched, cut, or unplugged, the controller won’t see any pedal signal.
Connectors could also be partially loose or corroded. Vibration from normal riding can gradually loosen connectors over time.
In some cases, zip-ties holding cables can be too tight and actually break the tiny wires inside (it happens!). Any break in the PAS wiring will mean no assist.
Water or Dirt Ingress
Though cadence sensors are usually sealed fairly well, water can sometimes get into connectors or the sensor unit, especially if you frequently ride in heavy rain or wash the bike with high-pressure water.
Moisture can short out the sensor or lead to corrosion on the contacts. Similarly, heavy buildup of mud or dirt around the sensor could block the magnetic field. (After muddy trail rides, it’s not a bad idea to clean around the bottom bracket area where the PAS resides.)
Controller or Setting Issues
Less common, but sometimes the controller might be misconfigured or faulty.
For example, if someone changed settings (like the number of PAS magnets in the controller software) to the wrong value, the assist might behave oddly or not engage. Or a failing controller might simply not process the sensor signal.
This is harder to diagnose, but generally if everything with the sensor hardware checks out and you still get nothing, the controller could be at fault.
Also, if both your throttle and PAS are unresponsive, the issue is likely beyond the cadence sensor (possibly a controller or power issue).
Understanding these causes, we can now move on to systematically troubleshooting and fixing the cadence sensor.
In most cases, you’ll find the issue is something simple like a misaligned magnet ring or a disconnected wire – things you can fix yourself with minimal tools.
Related: Electric Bike Controller Failure: Causes, Symptoms, and Solutions
DIY Troubleshooting Steps for a Cadence PAS Sensor
Let’s walk through the step-by-step process to diagnose and fix your pedal assist.
Always ensure the bike is off when plugging or unplugging any electrical connections, and use care when spinning wheels or cranks during tests (support the bike on a stand or have the wheels off the ground if possible).
Here’s how to troubleshoot your cadence sensor like a pro:
1. Verify Basic Settings and Power
Before diving into the sensor hardware, eliminate any simple user settings or power issues:
Battery and Power
Confirm that your e-bike’s battery is sufficiently charged and properly connected. A low or unseated battery can mimic sensor problems by cutting off assist.
Make sure the bike is powered on and not in an error state.
Assist Level
Check that you haven’t accidentally set the assist level to “0” or turned off pedal assist in the settings.
It sounds obvious, but on some displays it’s easy to overlook if the assist is off. Cycle through your assist modes and ensure you’re in one that should provide power.
Throttle Test
If your e-bike has a throttle, test it. Does the motor run when using the throttle (and the bike powered on)?
If throttle works but pedal assist doesn’t, it strongly suggests the cadence sensor is the issue, since the motor, battery, and controller are clearly functioning.
This is a great diagnostic clue: throttle-only operation means the bike’s power system is fine, so the PAS sensor or its signal is not reaching the controller.
Error Codes or Lights
Look at your display for any error code (some bikes might flash a code for sensor issues, e.g., “Error 21” or similar).
If an error is displayed, note it and check the manual – it could specifically indicate a PAS fault or something related.
Many times, though, as mentioned, a cadence sensor problem shows no error. Also, some sensor units have an LED indicator – if yours does, see if it lights up when the bike is powered (more on this later).
By confirming these basics, you ensure the problem truly lies with the pedal assist sensor and not with something like a drained battery or an engaged safety cutoff.
2. Ensure the Brake Cut-Off Isn’t Engaged
Nearly all e-bikes have brake cut-off switches on the brake levers – they send a signal to cut motor power whenever you pull the brakes (a critical safety feature).
However, if these sensors are misadjusted or a brake lever is sticking, the bike might “think” you are braking all the time, thus disabling pedal assist.
This can happen without you realizing: for example, a misaligned brake sensor magnet or a bent brake lever that doesn’t fully return.
To rule this out, check your brake levers:
Squeeze and release each brake lever a few times. They should snap fully back to their resting position when released. If a lever is slow to return or doesn’t come out all the way, its sensor might still be activated.
Most brake sensors consist of a tiny magnet on the lever and a sensor on the lever mount. Ensure the magnet hasn’t fallen out of its socket and that it lines up with the sensor when the lever is released.
With the bike on, try gently jiggling the brake levers forward (the opposite of pulling, i.e., ensuring they’re fully open). Sometimes a slightly loose sensor will think the brake is on when it isn’t.
If you suspect a brake sensor issue, you can temporarily disconnect the brake cut-off connectors (if you can locate them) and test pedal assist.
A “stuck” brake sensor will absolutely prevent PAS from engaging, so this is an important check.
In fact, one troubleshooting guide suggests unplugging the brake sensors as a test: if pedal assist works with them unplugged, you’ve found the culprit.
(Just be cautious riding without brake cut-offs — it means the motor won’t automatically stop when braking until you plug them back in.)
Ensuring the brake sensors are not falsely cutting power is a quick win – many a time riders have thought their bike was broken, only to discover the brake lever was slightly engaged or its sensor needed adjustment.
Once you’re sure the brakes aren’t the issue, we can focus entirely on the cadence sensor itself.
3. Inspect the Sensor and Magnet Ring Alignment
Now we get to the heart of most cadence sensor problems: alignment. Position yourself by the bike’s crank area and examine the cadence sensor setup:
Locate the Sensor
It’s usually a small plastic box or disc mounted near the crank. Common positions are attached to the chainstay, the bottom bracket shell, or even tucked behind the chainring. It will face the magnet ring.
Locate the Magnet Ring
This is a circular disk with multiple magnets, attached to either the crank arm or the spindle.
On some bikes it’s on the right side (chainring side) behind the chainrings, on others it could be on the left crank.
It may be a solid disk or a split two-piece ring that clips together around the spindle.
Check the Gap
The space between the sensor and the magnet ring should be very small – typically just a few millimeters. As mentioned earlier, around 1–3 mm is ideal.
If it looks significantly larger (say 5 mm or more), that’s likely too far for reliable sensing.
Often the magnet disk is designed to sit almost touching the sensor when properly installed. If you see a big gap, try pushing the magnet ring closer.
In many cases, the magnet ring can slide along the spindle. Push it gently toward the sensor (some have a set screw or a clip – ensure it’s secure after adjusting).
According to one e-bike manufacturer, the magnet wheel “should be right against the sensor” and if it slid away, just sliding it back in place “should solve most of the pedal assist issues.”
Alignment and Orientation
It’s not just distance; the sensor and ring should be aligned face-to-face.
If the sensor got twisted or bumped, it might not be pointing at the magnet disc anymore. Realign the sensor so it directly faces the flat side of the magnet ring (where the magnets are embedded).
Many sensors have a mark or arrow indicating the side that should face the magnets, and many magnet rings have an arrow showing which side points to the sensor – double-check these if present.
Essentially, the sensor’s “eye” should be looking squarely at the passing magnets.
Securing the Sensor
Ensure the sensor itself is firmly mounted and hasn’t come loose. If it’s attached with a bracket or screw, it shouldn’t wobble. A loose sensor might move away under pedaling forces.
Tighten any mounting screws if needed (but don’t strip plastic threads). If it’s held by zip ties, make sure they’re snug.
Count the Magnets (if needed)
While not a common issue, ensure the magnet ring hasn’t lost any magnets.
Most rings are sealed, but if yours has exposed magnet pieces and one fell out, the sensor might go “blind” during that portion of the rotation.
Replace any missing magnets or the ring if so. (Also, verify the number of magnets matches what your controller expects – if you recently changed the PAS ring from, say, 8 magnets to 12 magnets, some controllers need a setting update. This is more of an advanced check, usually not an issue on stock bikes.)
After Any Adjustments, Test the Bike
Turn on the power, lift the rear wheel, and pedal (or have someone pedal while the bike is on a stand).
If the alignment was the problem, the motor should now spring to life once you complete a partial pedal stroke (usually within a half-turn or so).
Often, simply correcting the sensor/magnet position fixes a dead pedal assist instantly – the sensor was “missing” the magnets, and now it can read them again. This step addresses the most frequent cause of PAS failures.
4. Clean the Sensor and Magnet Ring
While you’re down there, take a moment to examine the cleanliness of the sensor area.
Dirt, mud, or debris can cause two problems: it can physically obstruct the sensor from reading the magnets, and it can also lead to corrosion or sticking of parts.
Wipe Off Any Dirt
Use a damp cloth or gentle brush to clean both the sensor face and the magnet ring. Even fine dust can accumulate, so give it a good wipe.
If you see metal filings (sometimes happens if your bike’s chainring or other parts are grinding), definitely clean those out – they can stick to magnets.
Inspect for Gunk
Sometimes old grease, road grime, or even a small pebble could be stuck near the sensor. Remove anything that doesn’t belong. A clean sensor is an efficient sensor.
Check the Magnet Ring Slots
If it’s a slotted ring design (with openings), make sure nothing is wedged in there.
I’ve seen a case where a tiny twig got stuck in the magnet disc slots, which pushed the ring slightly off angle each rotation – weird, but possible. Removing it solved the issue.
Keep it Dry
If the area was water-logged, dry it out. For example, if you just rode in heavy rain, some connectors (if not waterproof) could be wet – gently dry around the sensor and connector.
In the long term, using dielectric grease on connector pins can help keep water out, though that’s optional. The key is no standing water or mud clumps around the sensor.
Regular cleaning is actually a good preventive habit. As one expert guide put it, “cleanliness is paramount” for sensors – keeping the PAS sensor and magnet ring free of debris ensures unobstructed operation.
In other words, a few minutes wiping down this area every so often can save you from future headaches.
After cleaning, again give the pedals a spin with the bike powered – sometimes, if dirt was the only issue, you’ll find the bike now reads pedal movement correctly and the motor assist returns.
5. Examine Wiring and Connections
If aligning and cleaning the sensor didn’t solve the problem, the next suspect is the electrical connection.
The cadence sensor typically connects to the main wiring harness via a small plug. A loose or damaged wire can break the communication. Here’s how to check:
Trace the PAS Cable
Follow the wire from the sensor (usually a thin cable) towards the controller. It often ends in a quick-disconnect connector a short distance from the sensor (sometimes near the down tube or under the bottom bracket). Locate this connector.
Inspect the Connector
Ensure it hasn’t come unplugged or partially loose. Many e-bikes use modular connectors with locking tabs or arrows that must be aligned.
If the connector looks even slightly separated, unplug it fully and then plug it back in firmly. Reconnect it securely, aligning any markings, until it clicks or is fully seated. A partially connected PAS plug can cause intermittent or no assist.
Check Connector Pins
While the connector is apart, peek inside.
Do you see any bent pins, corrosion (green or white crud) on the metal contacts, or moisture? If so, that’s likely the issue.
Clean corrosion gently with electrical contact cleaner or isopropyl alcohol and a cotton swab, and let it dry before reconnecting. If a pin is bent, very carefully straighten it with tweezers. Ensure no pins are pushed out the back of the connector housing.
Examine the Wire Itself
Look along the length of the wire for any cuts, squashed sections, or worn insulation.
Pay attention to where the wire might flex or be exposed – for example, where it exits the sensor housing, or where it enters the frame or controller area.
If you find a spot where the cable’s outer sheath is damaged and wires are exposed or broken, that’s a problem. A broken wire = no signal.
Minor insulation nicks can be patched with electrical tape or heat shrink, but a completely severed or frayed wire section might need replacement of the sensor (since the cable is usually fixed to it).
Wiggle Test
With the bike on, try wiggling the PAS cable and connector while pedaling (or have someone pedal slowly).
If the assist cuts in and out as you manipulate the cable, that indicates a loose connection or an internal break in the wire. Consistent behavior only when the cable is held a certain way means a likely wiring fault.
In such a case, replacing the sensor (which includes a new cable) is often the simplest solution, unless you’re handy with soldering small wires.
Brake and Other Connections
Also examine where the PAS cable plugs into the controller or harness – though most likely the small connector you found is that connection.
Ensure it’s plugged in to the correct mating connector (if you recently worked on the bike, sometimes one could mix up similar connectors, though most are keyed to prevent this).
By now, you’ve addressed alignment, cleanliness, and wiring – the main causes of cadence sensor failures.
If the sensor was misaligned, dirty, or unplugged, your pedal assist should be working again.
Give the bike a test ride in a safe area: does the motor engage when you pedal? If yes, enjoy your restored e-bike assist! If not, we have a couple more steps to consider.
6. Test the Sensor’s Function (Advanced Checks)
If the problem persists despite the above, it’s time to verify if the sensor is actually outputting a signal or not. There are a few ways to do this:
Look For the Red Light
Many cadence sensors have a tiny LED that serves as a visual indicator. It often lights up solid when the bike is powered, then flashes each time a magnet passes (i.e., as you pedal).
Position yourself so you can see this LED (it might be on the side of the sensor or even visible through a little window or hole).
Turn on the bike and rotate the pedals slowly by hand. If you see a blinking light on the sensor every time a pedal passes, it means the sensor is detecting magnets.
This is a good sign that the sensor itself works and the issue might be elsewhere (perhaps the controller not responding, though that is rare if everything else is fine).
If you never see a light at all (and you’re sure your model has one), then the sensor may not be getting power or is fried.
Keep in mind not all sensors have an LED, so lack of one doesn’t always mean failure – check your sensor’s specs if possible.
Use a Multimeter or Voltmeter
This is for the technically inclined. If you have access to the sensor’s wiring and know the pinout (usually 3 wires: +5V, ground, and signal), you can test the signal line.
Set a multimeter to DC voltage, connect the black probe to ground and the red probe to the signal wire (often green or yellow).
Manually turn the pedals. The signal wire should toggle between ~0 V and ~5 V as magnets pass, essentially pulsing on/off.
If you see this voltage switching, the sensor is working and sending data. If the signal stays flat (0 V or 5 V constantly) even as you pedal (and you have the probes correctly placed), the sensor isn’t outputting pulses – indicating a bad sensor or no power to it.
Controller Diagnostics
Some e-bike displays or apps (for smart controllers) let you access diagnostics that show PAS active or error codes for sensor issues.
If your bike has such features, check if it registers pedal movement on the display (some bikes show a pedal icon or wattage when you pedal in assist).
If nothing changes there when you pedal, again it suggests the controller isn’t “seeing” the sensor.
A few bikes might log an error code if the PAS signal is missing entirely. Consult the manual for any diagnostic mode or error code related to PAS (for example, some show “Error 25” for brake sensor issues, “Error 30” for communication issues, etc., which indirectly could involve PAS).
This Varies Widely by Brand.
If these tests indicate the sensor is not functioning (no blinking LED, no signal voltage pulses), then it’s likely time to replace the sensor.
If the sensor does seem to function (it blinks or gives pulses) but you still have no assist, then the controller might not be responding.
Double-check one more time that brake sensors are definitely not engaged (since a brake cut-off will override the PAS).
If possible, a controller reset could be attempted (disconnect the battery for a few minutes, then reconnect, or use any reset procedure recommended by the manufacturer), though a controller fault is relatively uncommon for just PAS issues.
7. Replace the Cadence Sensor if Necessary
After all the troubleshooting, you may conclude the cadence sensor itself is faulty. Perhaps it’s internally damaged or just not working despite your efforts.
Don’t despair – a cadence PAS sensor is generally one of the easiest and cheapest e-bike components to replace:
Get the Right Part
Ensure you obtain a compatible replacement. Many e-bike cadence sensors are generic 3-wire PAS sensors that work across models, but connector types differ.
Check your connector (for example, some use a Julet connector with a specific pin pattern). You can often buy the exact sensor from your bike’s manufacturer or a universal one from e-bike part suppliers.
They usually cost in the range of $10–$20.
Installation
Replacement typically involves removing the old sensor and magnet ring and installing the new ones in the same positions.
If your magnet ring is fine, you might only swap the sensor unit and plug it in. If the new sensor comes with its own magnet disc, use it if needed (e.g., if the magnet count is different or the old ring is damaged).
Mount the sensor securely, with the correct gap to the magnets as discussed. Many replacement sensors simply zip-tie to the frame. Reconnect the new sensor to the wiring harness.
Test the New Sensor
Power on the bike and pedal to see if assist returns. In a straightforward case, a new sensor that’s properly aligned will immediately restore pedal assist function that was lost.
As one repair guide notes, there isn’t much “extra testing” to do on these simple sensors – you plug the new one in and see if it works.
If it does, problem solved! You can ride happily again with full assist.
What if it still doesn’t work? If a brand-new sensor also doesn’t fix the issue, then the likelihood is that the fault lies in the controller or a deeper electrical problem.
At that point, you’ve ruled out all the basic causes (alignment, wiring, sensor unit).
For example, the controller’s PAS input might be fried. Replacing or servicing the controller would be the next step, which might be more complex and perhaps best handled by a professional or under warranty if applicable.
But it’s worth noting that actual controller failures causing only PAS issues are not very common – so replacing the sensor usually does the trick.
Don’t be intimidated by replacing the sensor – it’s a DIY-friendly job in most cases.
If your bike has an internal sensor (for instance, some mid-drive motors have the cadence sensor built into the motor unit), that’s a different story – you might need to open the motor or have a technician do it. But most hub-motor kits and many city e-bikes use external cadence sensors that are modular.
Tips for Preventing Cadence Sensor Failure
Once you’ve fixed it, there are a few things you can do to minimize the chances of it happening again:
Periodic Checks
Every so often (perhaps each time you do a thorough bike cleaning or maintenance), glance at your PAS sensor setup.
Is the magnet ring still snug and close to the sensor? Are the wires intact and secured out of harm’s way? This quick check can catch a sensor that’s starting to drift out of alignment or a cable that’s rubbing, before it actually causes a ride interruption.
Keep it Clean and Dry
As part of routine maintenance, clean the sensor and magnet area. It only takes a minute to wipe off dust or spray from puddles. Keeping the area clean prevents buildup that could interfere with the sensor.
Also avoid direct high-pressure spraying at the bottom bracket – water forced in could impact the sensor or wiring. If you ride in rain, maybe give the connectors a shot of WD-40 Specialist (for electrical) or contact cleaner afterward to dispel moisture.
Check Your Chain Tension and Drivetrain
An overly loose chain flopping around can knock into things – even the magnet ring as noted in some cases. Maintain proper chain tension (for single-speed or hub-motor bikes) and ensure nothing is contacting the PAS magnet disc while riding.
Secure Cables
Make sure the PAS cable (and others) are not only free of damage but also secured so they won’t snag on debris or get pulled.
A loose cable can catch a stick or get yanked, unplugging the sensor. Use zip ties or clips to keep it neatly routed, with a little slack at pivot points (like suspension or folding joints, if applicable).
Know Your System
It helps to familiarize yourself with how your particular e-bike’s assist works. For example, if your display lets you adjust settings like wheel size or magnet count, ensure those are correct because a wrong setting can make the assist behave poorly.
If your bike ever starts acting up again, you’ll now know to methodically check the sensor alignment and connections as a first response.
Conclusion: Keeping Your Pedal Assist Reliable
Riding an e-bike is a joy, and having the pedal assist working properly is key to that experience. Thankfully, cadence sensor troubleshooting doesn’t require special skills beyond basic bike tinkering.
By exuding a bit of patience and using the steps above, you can usually diagnose the issue and get your pedal assist running smoothly again.
And if not, you’ve gathered enough information to know when it’s time to consult a professional or consider a controller repair.
Trust your DIY instincts – with a little effort, you’ve saved time and money and gained a deeper understanding of your e-bike’s inner workings.
Now, hit the road and enjoy that sweet electric boost on every pedal stroke!
