Why is My Electric Bike Motor Cutting Out?

electric bike motor cutting out

You’re riding up a hill on your otherwise well-performing electric bike and it suddenly happens: the jerking and sputtering of the electric bike motor cutting out. Even owners of the best-quality e-bikes have had this unpleasant experience.

There can be several issues causing your electric bike motor to cut out. Symptoms may point to a true “end of life” of the motor itself due to wear and tear or it can be a simple and fixable issue with loose connections in the wiring itself.

Loose connections are generally due to the natural vibrations involved in running the motor and riding. Other working components of the e-bike may also experience wear due to vibrations and stress. Riders may experience the electric bike motor cutting out more often when the motor is put under stress such as in an uphill ride or when putting more load or weight on the bike. 

If more current is required to flow through the bike’s wiring, any loose or inadequate connections are going to be more apparent to the rider. This may be apparent through a noticeably jerk or delays in propulsion.

Propulsion delays can also be caused by the effect of cold weather on the bike’s battery. Low temperatures can affect the battery’s ability to discharge energy and can also impact the battery’s ability to charge. It may be more noticeable that the bike motor is cutting out when the load is more than the motor can bear because it is older and nearer the end of its useful life.

How Long Does an Electric Bike Motor Last?

Several factors determine how long an electric bike motor will last. The quality of the motor and associated electrical components, the size and power of the motor, and how the bike is ridden can all contribute to the duration of the motor’s useful life. Regular maintenance of all of the working components, including the brakes, chain, tired and battery, can also determine how long the e-bike’s motor will last.

On average, experts say that electric bike motors should last for around 10,000 miles. An electric bike motor’s life can be reduced if it is too large, or consumes too much power for your usage. Putting too much weight or load on the motor can cause more wear and tear.

Even your style of riding can affect how long your electric bike motor will last. You can reduce the lifespan of your e-bike motor if you like to gun the throttle or fail to pedal to help the motor propel the bike. Experts recommend utilizing only between 70% and 80% of total throttle output. Additionally, failing to replace other critical components on the bike can create more drag and require the motor to work harder.

To make sure your electric bike motor lasts as long as possible, it’s best not to purchase a bike motor with wattage that is overpowered for your local area’s speed limits. Higher wattage motors consume more power, so a larger battery is needed to support them. There is a downside to having a powerful motor when you aren’t able to travel the intended speed due to speed limits in your area. 

Not only do more powerful motors with larger batteries cost more, but they are also heavier and add to the load which accelerates wear and tear and reduces how long your electric bike motor will last. Motors between 500 and 750 watts (up to 1100 watts) is typically too much power for the average electric bike commuter. 

These powerful bikes will also reflect a more hefty price tag and still require the rider to pedal up hills. It is good to keep in mind that it is more likely that other components on the bike, such as brakes, chains, and tires, will require maintenance or replacement much sooner than the motor or battery.

Conversely, purchasing an e-bike with an under-powered or low-quality motor can produce the same result. Attempting to draw energy from a bike motor that by design does not have the ability to deliver the performance you need will likely have a shorter overall useful life. 

Experts recommend a minimum motor size of 250 watts for commutes involving hills, with 350 watts being a more optimal size for riders weighing more than 200 pounds- assuming the rider will contribute energy through pedaling.

In fact, e-bike riders should plan on a decent amount of pedaling if they want their e-bike’s motor to last, especially in hilly terrain. E-bikes aren’t designed to throttle up steep inclines without pedaling assistance from a rider, and regularly using the throttle at full capacity up hills can drain the battery as well as shorten the length of the motor’s life. Many potential e-bike owners mistakenly believe that e-bikes, like electric scooters, will carry them up hills through electric power only. Only bikes at the high-end of the power spectrum, in the category of 1,000+ watts, are capable of achieving this.

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What To Do When Your E Bike Motor Is Not Working

If your e-bike motor stops working, try to determine if your motor is at the end of its useful life, based on your usage of the bike. If you have not yet reached 10,000 miles on your bike, a simple troubleshooting exercise and component repair or replacement may get you on your way quickly.

Begin by investigating the easiest and least expensive reasons why your e-bike motor is not working properly. Are there any obviously loose connections or wiring? The “jerky” feeling you get from your e-bike motor kicking in likely explains a disconnect in the electrical current.

Charging Habits

Charging habits can also be a factor in the battery’s performance and lifespan. Have you consistently drained the battery through usage so that your battery is able to charge to capacity when you plug it in? It is important for batteries to drain so that stored energy can be replaced with energy from a new charge.

To learn more about how to properly charge an ebike battery, check out our post: Tips for Charging Your Ebike Battery for the First Time


Temperature is also an important factor. Batteries charged outdoors in cold or humid climates will be negatively impacted and most manufacturers recommend charging in ambient temperatures between 40 and 90 degrees Fahrenheit. Batteries are best charged and stored indoors and should come to room temperature before they are charged. Riders should make a habit of removing their battery and taking it indoors each time they ride for maximum protection against temperature fluctuations and moisture.


Lastly, ask yourself the age-old Help Desk question, “Is it plugged in?” If your e-bike motor is not working, make sure you didn’t accidentally forget to charge it or experience a failed charge, such as a non-working outlet.

Diagnose the Issue

Check all connections (including pin connectors) to ensure they are making full contact as well as sealed from moisture that can cause corrosion. If there is evidence of corrosion, wiring or connectors will likely need to be replaced. 

Next, focus on the working condition of major components. Is your chain properly oiled and your tires at the required air pressure, allowing the bike to run smoothly? Are poorly maintained brakes creating too much drag when not engaged? Has the battery pack sustained any physical damage or been compromised in any way?

A voltmeter can tell you if your battery is fully charged and isolate or eliminate the battery as the source of the motor function issue. A more expensive but effective troubleshooting tool is a diagnostic dashboard, such as CycleAnalyst, which can analyze the e-bike’s computer, battery draw and energy remaining in the battery pack, regenerative energy gained from braking, peak and minimum currents, as well as battery cycles and amp-hours used over the course of the battery’s life.

An analytical tool is not only useful when experiencing poor motor performance, but it can also be useful when the motor is performing well. Regular use of diagnostic tools can pinpoint when and what kind of upcoming maintenance will be required.

This type of tool can also allow users to pre-program power usage parameters to customize and optimize the motor’s performance. Sadly, replacing the battery is the most expensive part of on-going maintenance, aside from the replacement of an aged or worn-out motor.

Keeping all components in check and peddling as much as you can to help the motor are the best and least expensive ways to keep your motor in good working order, allowing you to delay any major parts replacements.

Final Thoughts

Prevention is key. Choosing an e-bike with power requirements that are right for you and your riding style is the first step. Taking care of your motor through a lowered load and smoothly running components is critical. Riding your e-bike and charging it in ways that help extend the life of the motor and the battery can help you maximize the mileage you get from your e-bike. Be especially aware of how temperature and moisture may be affecting your motor, battery and other components.

Most e-bike component maintenance can be done at home, but e-bike maintenance and repair that involves replacing the battery or motor will require a technician and could be costly relative to the price of a new e-bike.

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