Troubleshooting Your Electric Bike's Slow Performance

If your electric bike is slowing down, there are a number of potential causes. The most common cause is a problem with the battery, which is the 'lifeblood' of your e-bike. As the battery depletes, ages, or sags, the voltage and current capabilities decrease, resulting in reduced power and speed. This can be avoided by keeping the battery charged above 25%. Other potential causes include underinflated tires, brake or bearing issues on the wheels, riding the bike in a heatwave, or a speed limiter.

Battery issues

If your electric bike is slowing down, the first thing you should do is check the battery. The battery is the lifeblood of your e-bike, providing power to the motor. Start by ensuring that the battery is fully charged. If it’s not, plug it in and allow it to charge completely. If you have a removable battery, you can also try swapping it with a spare one if available.

As your battery depletes or ages, both current and voltage capabilities decrease, resulting in reduced power and speed. This is known as 'battery sag'. If your battery is too old or you haven’t been taking good care of it, the culprit for your electric bike suddenly turning slower might be battery sag. Have the battery inspected and replace it with a new one if necessary.

To keep your battery in good condition, it's important to keep it above 25% charge, monitor the voltage, and maintain proper tire pressure. Seek help if there’s sudden power loss, unusual voltage behaviour, or if the battery won’t hold a charge.

When voltage drops below 32V, most controllers reduce power output to protect the battery, making your bike feel sluggish. This is why your bike feels slower when the battery gets low.

Speed limiter

One of the reasons your electric bike might be slowing down is because of a speed limiter. Speed limiters are often set by the manufacturer to prevent the bike from exceeding a certain speed, which can help to improve battery life and reduce wear and tear on the motor.

If you find that your electric bike is consistently slowing down, even when riding on flat terrain, it may be due to a speed limiter that has been activated. This could be due to a number of factors, such as the bike's motor reaching a certain temperature or the battery dropping below a certain voltage.

To determine if a speed limiter is the cause of your bike's slowdown, you can check the bike's settings or consult the owner's manual. Some electric bikes allow you to adjust the speed limiter settings, while others may require a professional diagnosis and adjustment.

It's important to note that speed limiters are designed to protect the bike's components and ensure a longer lifespan. However, if you feel that the speed limiter is too restrictive or is affecting your riding experience, it may be worth consulting a specialist to see if any adjustments can be made.

In addition to speed limiters, there are several other factors that can contribute to an electric bike slowing down. These include underinflated tires, brake or bearing issues, riding in hot weather, and most commonly, battery issues. Proper maintenance and regular checks of your bike's components can help prevent unexpected slowdowns and ensure a smoother riding experience.

Underinflated tires

One of the most common reasons for an electric bike slowing down is underinflated tires. Ensuring your tires are properly inflated is essential for maintaining optimal performance.

Tire pressure plays a crucial role in the overall efficiency of your electric bike. When tires are underinflated, they create more rolling resistance, requiring the motor to work harder to maintain speed. This increased resistance translates directly into reduced power and speed, making your bike feel sluggish.

Maintaining proper tire pressure is a simple yet effective way to maximise your bike's performance and range. By keeping your tires inflated to the recommended pressure, you reduce the rolling resistance, allowing the motor to operate more efficiently. This not only improves speed but also enhances the overall riding experience, making it smoother and more enjoyable.

Checking your tire pressure regularly is a good habit to develop. Invest in a reliable tire pressure gauge and familiarise yourself with the recommended pressure for your specific tires. This information is usually printed on the sidewall of the tire or can be found in the manufacturer's manual.

Additionally, consider investing in a portable pump or compressor to top up your tire pressure as needed. This way, you can quickly address any pressure loss and ensure your tires are always optimally inflated, keeping your electric bike running at its full potential.

Brake or bearing issues

If your electric bike is slowing down, it could be due to brake or bearing issues. Brakes and bearings are essential components of your e-bike's braking system, and problems with either can significantly impact your bike's performance and safety. Here are some things to consider:

Brake issues:

• Check your brake pads for wear and tear. Over time, brake pads can become worn down, reducing their effectiveness. Inspect the pads for any signs of glazing, cracks, or uneven wear. If the pads are worn, they may need to be replaced.
• Ensure that your brake cables are properly adjusted and lubricated. Loose or frayed cables can affect braking performance.
• Check the brake fluid level and condition. If the fluid is low or contaminated, it can impact the brake's ability to engage and disengage smoothly.

Bearing issues:

• Wheel bearings: These facilitate the smooth rotation of your wheels. Over time, bearings can become worn, causing increased friction and resistance, which can slow down your bike. Listen for any unusual grinding or squealing noises coming from your wheels, as this could indicate worn bearings.
• Headset bearings: These bearings allow your handlebars and front wheel to turn smoothly. Worn or damaged headset bearings can make steering difficult and may also contribute to a slower ride. Check for any play or looseness in the headset and handlebar area.

If you suspect issues with your brakes or bearings, it is essential to have them inspected and serviced by a qualified bike mechanic. Proper maintenance and timely replacement of worn components will help ensure optimal performance and a safer riding experience. Remember to consult your e-bike's user manual for specific maintenance guidelines and always follow the manufacturer's recommendations.

Riding in a heatwave

Firstly, check the battery. The battery is the lifeblood of your e-bike, providing power to the motor. Make sure that the battery is fully charged. If it’s not, plug it in and allow it to charge completely. If you have a removable battery, try swapping it with a spare one if you have one. Keep the battery above 25% charge and monitor the voltage. If there is a sudden power loss, unusual voltage behaviour, or if the battery won’t hold a charge, seek help.

If your battery is old or you haven’t been taking good care of it, the culprit for your electric bike slowing down might be battery sag. This is when a worn battery drops in voltage as the motor starts drawing power from it, reducing the motor’s speed of rotation. Have the battery inspected and replaced if necessary.

Some power loss is normal over time, but proper maintenance and understanding your system can help maximise performance and longevity. Keep your tires properly inflated and maintain proper tire pressure for optimal performance.

Frequently asked questions