Everything You Need to Know About Pedal Assist Electric Bikes
Pedal assist on electric bikes is a feature that provides additional motorized power as you pedal, making cycling easier and more enjoyable. By seamlessly boosting the rider's pedaling effort, pedal assist allows users to cover longer distances, tackle hills with ease, and reduce physical strain. This feature enhances the cycling experience for a wide range of riders, from daily commuters and casual cyclists to those seeking assistance due to physical limitations, making biking more accessible and efficient.
What is Pedal Assist and How Does It Work
Pedal assist, commonly referred to as PAS (Pedal Assist System), is a feature on electric bikes that provides motorized support as you pedal. Unlike a throttle-only system, where the motor is engaged by manually twisting or pressing a throttle, pedal assist automatically boosts your pedaling effort based on the level of assistance you select.
How It Works:
The system relies on a PAS sensor, which is usually mounted near the bike's crank or pedals. This sensor detects your pedaling motion and sends signals to the e-bike's controller. The controller then calculates how much motor assistance to provide, proportional to your pedal speed or torque (how hard you're pedaling).
- Cadence Sensors: These detect how fast you're pedaling. As you turn the pedals, the cadence sensor signals the motor to provide a pre-set level of assistance based on the pedaling speed.
- Torque Sensors: More advanced systems use torque sensors to measure the force you're applying to the pedals. This allows for more precise assistance, providing more motor power the harder you pedal.
The pedal assist mode allows for a smooth and natural riding experience, reducing physical strain while maintaining the sensation of pedaling. Riders can typically choose between multiple assist levels, ranging from low to high, depending on how much help they need.
Difference from Throttle-Only Systems:
In contrast to pedal assist, throttle-only systems allow you to control the motor with a twist grip or button, without needing to pedal. While throttle systems offer more direct control over the bike's speed, pedal assist provides a more integrated, cycling-focused experience, encouraging pedaling while still offering a substantial boost when needed.
Types of Pedal Assist Electric Bikes
| Type of Pedal Assist E-Bike | Description | Best For |
|---|
| City/Commuter E-Bikes | Lightweight, efficient, and designed for urban commuting with moderate pedal assist levels. | Casual commuters and city riders who want a convenient and eco-friendly way to get around town. |
| Folding E-Bikes | Compact and foldable, with pedal assist to make riding in urban areas more manageable. | Riders with limited storage space, commuters who use public transport, or anyone who needs portability. |
| Mountain E-Bikes (eMTBs) | Built for off-road terrain with powerful pedal assist and enhanced torque for climbing. | Off-road enthusiasts, adventure cyclists, and riders tackling steep hills and rugged trails. |
| Road/Performance E-Bikes | Designed for high-speed and long-distance rides, offering multiple levels of assist for efficiency. | Long-distance cyclists, fitness riders, and those looking for a fast, smooth riding experience on paved roads. |
| Fat Tire E-Bikes | Equipped with wide tires and pedal assist for better traction and stability on diverse terrain. | Riders navigating snow, sand, or rough terrain, as well as those seeking a more comfortable, cushioned ride. |
| Hybrid E-Bikes | Versatile bikes with moderate pedal assist, blending features of road and mountain bikes. | Riders who want flexibility for both urban commuting and light off-road adventures. |
| Cargo E-Bikes | Pedal assist designed to carry heavy loads or passengers, often with increased torque. | Families, delivery riders, or anyone needing to transport goods while still benefiting from motor assistance. |
| Step-Through E-Bikes | Easy to mount and dismount, with pedal assist suited for riders with mobility concerns. | Older riders, those with limited flexibility, or commuters seeking an easy and comfortable ride. |
Key Features of Pedal Assist E-Bikes
1. Electric Assist Bike System
- The electric assist system is the core of a pedal assist e-bike, combining the motor, battery, and controller to provide power as the rider pedals. This system engages automatically based on the rider's input and selected assist level, offering various modes ranging from low assistance for light pedaling to high assistance for more demanding conditions like steep hills.
- Benefit: The system delivers extra power seamlessly, making cycling easier without completely replacing the rider's effort, which helps conserve battery life and encourages a natural riding feel.
2. PAS (Pedal Assist System) Sensors
- Cadence Sensors: These sensors detect the speed at which the pedals are turning and provide motor assistance based on pedal rotation. The faster you pedal, the more assistance the motor provides.
- Torque Sensors: These sensors measure the force applied to the pedals and adjust the motor assistance proportionally. More force results in more power from the motor.
- Benefit: Both types of sensors contribute to a smooth and responsive ride, with torque sensors offering a more intuitive, force-based experience and cadence sensors providing a simpler, speed-based system.
3. Motor (Hub or Mid-Drive)
- E-bikes are equipped with either hub motors (mounted in the wheel) or mid-drive motors (mounted near the bike’s bottom bracket). Hub motors are generally simpler and more affordable, while mid-drive motors provide better torque, efficiency, and control.
- Benefit: The motor type influences how the bike performs in different terrains. Mid-drive motors excel at climbing hills and providing a balanced ride, while hub motors are great for smooth, straightforward commutes.
4. Battery
- Pedal assist e-bikes come with various battery capacities, typically ranging from 36V to 52V. Higher capacity batteries allow for longer ranges and better performance, especially when using higher levels of assistance.
- Benefit: A well-sized battery ensures that riders can travel longer distances with enough power to assist in various riding conditions, from flat city streets to hilly terrains.
5. Controller
- The controller acts as the “brain” of the e-bike, interpreting signals from the PAS sensor and adjusting the amount of power sent to the motor. It determines how much assistance is provided based on the selected mode and pedal input.
- Benefit: The controller helps balance power usage, ensuring the motor delivers smooth assistance when needed without draining the battery too quickly.
6. Multiple Assist Levels
- Pedal assist e-bikes typically offer 3-5 assistance levels, allowing riders to adjust how much help they receive from the motor. Lower levels offer minimal assistance, extending battery life, while higher levels provide maximum power for challenging terrain or higher speeds.
- Benefit: Riders can customize their experience based on their fitness level, riding conditions, and battery needs, ensuring a flexible and efficient ride.
7. Display Unit
- Most e-bikes come equipped with a display unit that provides information on speed, battery level, distance traveled, and current pedal assist level. More advanced displays may offer additional data such as ride time and power consumption.
- Benefit: The display allows riders to monitor their e-bike’s performance and adjust settings on the go for a more controlled and informed ride.
Comparing Pedal Assist vs. Throttle on E-Bikes
| Feature | Pedal Assist (PAS) | Throttle-Based System |
|---|
| How It Works | Provides motor assistance when you pedal, adjusting power based on your effort or speed. | Engages motor power by twisting a throttle or pressing a button, independent of pedaling. |
| Control | Power is based on pedal input and effort, allowing for a more natural cycling experience. | Direct control over power; the rider can accelerate without pedaling. |
| Pros | - Offers a more natural cycling feel - Helps conserve battery life - Encourages physical activity and exercise - More efficient for long-distance rides |
- Convenient for quick acceleration or starting from a stop - Ideal for riders who want minimal physical effort - Great for short trips or stop-and-go traffic |
| Cons | - Requires continuous pedaling, even at low assist levels - May be less suitable for riders with limited mobility - Not as ideal for stop-and-go riding |
- Can drain the battery faster, especially at higher speeds - Can feel less like traditional cycling - Less efficient over long distances |
| Best For | - Commuters who want to balance exercise with assistance - Long-distance cyclists - Riders looking for a more natural biking experience |
- Urban commuters in heavy traffic - Riders who prefer little to no pedaling - Those needing quick acceleration or minimal physical effort |
| Battery Usage | Generally more efficient, as motor assists only when pedaling. | Can drain battery quickly if used consistently at high speeds or without pedaling. |
| Terrain Suitability | Ideal for flat roads, hills, and long-distance rides due to efficient power use. | Good for flat terrain and stop-and-go traffic, but less efficient on hills without pedaling. |
| Physical Effort | Requires pedaling, making it a better option for those looking to get some exercise. | Minimal physical effort required, suitable for riders who prefer less pedaling. |
Benefits of Pedal Assist for Riders
Reduced Fatigue:
- Pedal assist e-bikes help reduce the physical effort needed to ride, especially over long distances or hilly terrain. The motor provides extra power as you pedal, minimizing muscle fatigue and allowing riders to go farther without overexerting themselves. This makes e-bikes accessible for riders of all fitness levels, including those who may have limited physical capacity or want to cycle without getting too tired.
Increased Range:
- By assisting your pedaling efforts, pedal assist e-bikes allow you to conserve energy and extend the range of your ride. Since the motor only activates when you pedal, the battery drains more slowly compared to throttle-only systems, resulting in longer distances between charges. This is especially useful for commuters, long-distance cyclists, and riders who want to cover more ground without worrying about battery life.
Easier Hill Climbing:
- One of the most appreciated benefits of pedal assist is its ability to tackle hills effortlessly. The motor kicks in to provide extra torque as you climb, allowing you to ascend steep hills without straining or slowing down significantly. This makes riding in hilly areas much more manageable and reduces the intimidation of steep inclines for casual cyclists.
Encourages Regular Exercise:
- While pedal assist reduces the effort required, it still encourages regular pedaling, which can improve cardiovascular health and fitness. Riders can adjust the level of assistance based on their fitness goals, choosing lower levels of assist for more of a workout or higher levels for a more relaxed ride. This balance of assistance and physical activity makes pedal assist e-bikes a great tool for staying active without overexertion.
Efficient Use of Battery Power:
- Because the motor only activates when you pedal, pedal assist e-bikes use battery power more efficiently than throttle-based systems. Riders can select lower levels of assist when they don’t need as much power, conserving battery life for when it's needed most, such as climbing hills or riding long distances.
Improved Speed and Performance:
- Pedal assist enables riders to maintain higher average speeds with less effort. This makes commuting faster and more efficient, allowing riders to reach their destinations quicker without feeling exhausted. The assistance also makes headwinds and rough terrain more manageable, maintaining consistent speed and comfort.
Accessible to a Wide Range of Riders:
- Pedal assist e-bikes cater to riders of all ages and fitness levels. For older riders, individuals with mobility issues, or those recovering from injury, pedal assist provides a level of support that makes cycling feasible and enjoyable without requiring significant physical exertion. It also opens up the world of cycling to those who may have previously avoided it due to physical limitations.
How to Choose the Right Pedal Assist E-Bike
| Factor | Description | Recommended Options |
|---|---|---|
| Primary Usage | Type of riding (commuting, recreation, fitness, cargo). | - Commuting: City/commuter e-bike - Recreational: Hybrid or step-through e-bike - Cargo: Cargo e-bike |
| Terrain | Type of surface or environment (flat, hilly, mixed). | - Flat roads: Hub motor e-bike (250W-350W) - Hilly terrain: Mid-drive motor e-bike (500W-750W) |
| Motor Power | Affects speed, hill climbing, and ability to handle loads. | - Low power (250W-350W): Best for flat terrain - High power (500W-750W): Ideal for hills or heavy loads |
| Battery Capacity | Determines the range of the e-bike. | - Short rides: 250Wh - 400Wh - Long rides: 500Wh - 600Wh or higher |
| Assist Levels & PAS | Controls the motor’s assistance level based on pedaling speed or force. | - 3-5 assist levels: Flexibility for different riding conditions - Torque sensor: More responsive assist |
| Comfort Features | Frame type, suspension, and brakes for comfort and safety. | - Step-through frame for easy mounting - Suspension forks for smoother rides - Disc brakes for safety |
| Budget | Price range based on performance needs and features. | - Entry-level: $1,000 - $1,500 - Mid-range: $1,500 - $3,000 - High-end: $3,000+ |
Understanding PAS Sensors on Electric Bikes
| Type of PAS Sensor | Description | Impact on Riding Experience | Best Use Case |
|---|
| Cadence Sensor | Measures pedal rotation speed (how fast you're pedaling). | Provides consistent assistance based on pedal speed, regardless of pedal pressure. It’s less precise but simple to use. | Best for casual riders and commuters looking for an easy, low-effort ride. |
| Torque Sensor | Measures pedal pressure (how hard you're pedaling). | Delivers power proportionally based on how much force you apply, offering a smoother and more natural ride. Great for climbing hills. | Ideal for hilly terrains, fitness riders, and long-distance cyclists needing responsive assistance. |
| Combined Sensor | Integrates both cadence and torque data to offer balanced assistance. | Offers the most precise and dynamic assistance by adjusting power based on both speed and pedal effort, ensuring optimal riding efficiency. | Suitable for riders seeking the best balance between comfort and performance in varying terrains. |
Legal Considerations for Electric Assisted Pedal Cycles
| Requirement | Description |
|---|---|
| Max Speed | Motor assistance must cut off at 32 km/h (20 mph). |
| Max Motor Power | Motor power limited to 500 watts. |
| Throttle | Allowed, but motor must cut off at 32 km/h. |
| Age Restriction | 16 years old (varies slightly by province). |
| Helmet | Mandatory for all riders. |
| License, Registration, Insurance | Not required for legal EAPCs (below 500W and 32 km/h). |
| Road and Path Use | Allowed on roads and bike paths, with some local restrictions. |
Maintenance Tips for Pedal Assist E-Bikes
1. Battery Care
- Charge Regularly: To keep your battery in top shape, recharge it after each ride or when it drops to around 20-30% capacity. Avoid fully depleting the battery, as this can reduce its lifespan.
- Store Properly: If you're not using your e-bike for an extended period, store the battery in a cool, dry place and charge it to about 50-70%. Extreme temperatures (hot or cold) can damage the battery.
- Clean Battery Terminals: Keep the battery terminals clean and free of dust or debris, which can affect the connection between the battery and the motor. Use a dry cloth or an appropriate electronic cleaner to clean the terminals.
- Avoid Overcharging: Overcharging can harm your battery. If your charger doesn’t have an auto-shutoff feature, monitor the charging process to avoid leaving it plugged in overnight.
2. Check PAS Sensors
- Clean Sensors Regularly: Dirt, mud, or debris can block your cadence or torque sensors, causing erratic performance. Check the sensor near the crank or wheel hub and gently clean it with a soft cloth to ensure proper function.
- Test for Accuracy: Periodically test the pedal assist response by riding your e-bike on different assist levels. If the response feels delayed or inconsistent, the sensor may need to be recalibrated or cleaned.
- Check Sensor Alignment: Make sure that the magnet rings on your cadence sensor or torque sensor are properly aligned and not loose. Misaligned sensors can lead to improper motor assistance.
- Recalibrate Sensors: Some e-bikes allow you to recalibrate torque sensors through the display settings. This may help restore smooth, consistent pedal assistance if the system feels off.
3. Motor Maintenance
- Keep the Motor Clean: Regularly clean your motor housing with a damp cloth to remove dust and grime, especially after riding in wet or muddy conditions. Avoid using a pressure washer as water can damage electrical components.
- Inspect Motor Wiring: Check for any loose or damaged wires that connect the motor to the battery or controller. If you notice frayed wires, repair them or consult a technician to prevent electrical shorts or malfunctions.
- Monitor Motor Noise: If you hear unusual sounds like grinding or clicking from the motor, it could indicate that parts need lubrication or that there is internal wear. Contact a professional if motor noises persist.
4. Brake and Tire Checks
- Check Brake Pads: Since e-bikes are heavier and faster than standard bikes, the brake pads wear out faster. Inspect your brake pads regularly and replace them if they’re worn down to maintain safe stopping power.
- Tire Pressure: Ensure that your tires are properly inflated. Underinflated tires cause more friction and drag, reducing battery efficiency and overall range. Check tire pressure frequently and follow the manufacturer's recommended PSI levels.
- Inspect Tires for Wear: E-bike tires experience more wear due to the increased weight and speed. Look for bald spots, cuts, or bulges, and replace the tires if they’re showing signs of excessive wear.
5. Controller and Wiring
- Inspect the Controller: The controller manages the power distribution between the motor, battery, and PAS system. Ensure it stays dry and clean by regularly wiping it down. If you notice erratic performance, check the controller for any error codes displayed on the screen.
- Check Wiring Connections: E-bikes rely on wiring to transfer power between components. Regularly inspect the wiring for loose connections, corrosion, or damage. Use dielectric grease on connectors to prevent corrosion and improve connectivity.
6. Chain and Drivetrain Maintenance
- Lubricate the Chain: Regularly lubricate the chain to reduce friction and ensure smooth pedaling. E-bikes put more strain on the chain due to the added motor power, so it’s essential to apply chain lube more frequently, especially after wet rides.
- Inspect the Drivetrain: Keep the gears, chainrings, and derailleurs clean and well-maintained. Dirt and grime buildup can cause poor shifting performance, reducing the efficiency of your pedal assist system.
- Replace Worn Components: If you notice skipping gears or excessive wear on the chain or cassette, it may be time to replace those components. E-bikes tend to wear out drivetrain components faster due to their higher torque.
7. Tighten Bolts and Fasteners
- Check Regularly: The added speed and weight of an e-bike can loosen bolts over time. Regularly inspect and tighten the key bolts, including those on the handlebars, seat post, pedals, and wheels.
- Use Torque Wrench: When tightening bolts, use a torque wrench to ensure they are tightened to the manufacturer’s specifications. Over-tightening can damage components, while under-tightening can lead to parts becoming loose.
8. Regular Software Updates
- Check for Firmware Updates: Some modern e-bikes have programmable controllers or displays. Check with the manufacturer to see if any firmware updates are available. These updates can improve battery management, motor efficiency, or sensor accuracy.
- Resetting the System: If your e-bike starts acting sluggish or the pedal assist is inconsistent, try resetting the e-bike's system (through the display). This can sometimes resolve minor software issues.