1. Setup and Assembly
This section provides step-by-step instructions for assembling your QNUT Retro Ebike. Please follow these steps carefully to ensure proper setup and safe operation.
Video 1.1: Ebike Assembly Instructions. This video demonstrates the complete assembly process for the QNUT Retro Ebike, including handlebar, front wheel, headlight, fender, and pedal installation. It also shows the initial power-on sequence.
1.1. Unboxing and Preparation
Carefully remove all components from the packaging. Ensure all parts and tools are present before beginning assembly. The main frame, rear wheel, and battery are pre-assembled.

Figure 1.1: QNUT Retro Ebike and included accessories. This image displays the fully assembled ebike along with the portable air pump, cup holder, and frame bag.
1.2. Handlebar Installation
- Unscrew the four bolts on the handlebar stem using the provided Allen wrench.
- Position the handlebar into the stem, ensuring it is centered and aligned.
- Tighten the four bolts securely, alternating to ensure even pressure.
- Adjust the handlebar angle to your preferred riding position and tighten the screws.
1.3. Front Wheel Installation
- Unscrew the two bolts and remove the plastic spacer from the front fork.
- Carefully align the front wheel with the fork, ensuring the brake disc slides correctly into the brake caliper.
- Insert the axle bolts and secure them with the small safety iron pieces on both sides.
- Tighten the bolts on both sides using the provided wrench.

Figure 1.2: 20"x4.0" Fat Tires. These tires provide stability and traction across various terrains, including city roads, mountain trails, snow, and sand.
1.4. Headlight and Fender Installation
- Attach the headlight bracket to the front fork using the provided screws and wrench.
- Mount the headlight onto the bracket and tighten the screws.
- Connect the headlight cable by aligning the two interfaces and pushing them together.
- Install the front fender by unscrewing the bolts above the tire, positioning the fender, and re-tightening the bolts.

Figure 1.3: Upgraded LED Lighting System. The ebike features a composite lens system for the headlight and sequential turn signals for enhanced road safety.
1.5. Pedal Installation
- Identify the 'L' (left) and 'R' (right) pedals.
- Install the 'L' pedal on the left crank arm and tighten it with a wrench.
- Install the 'R' pedal on the right crank arm and tighten it with a wrench.
1.6. Basket Installation (if applicable)
- Unscrew the designated bolts on the bicycle frame for the basket.
- Position the basket and align it with the screw holes.
- Insert and tighten the screws to secure the basket firmly.
1.7. Initial Power On and Display Check
- Ensure the battery is securely installed and the power switch on the battery is turned ON.
- Long-press the start button on the handlebar controls to power on the display.
- Verify that the display lights up and shows basic information like battery level and speed.

Figure 1.4: 5.4-Inch High-Resolution Smart LCD Display. The display provides real-time data including speed, battery level, gear selection, and mileage, with anti-glare coating for clear visibility.
2. Operating Your Ebike
Familiarize yourself with the controls and features of your QNUT Retro Ebike for a safe and enjoyable riding experience.
2.1. Powering On/Off
- To power on: Insert the key into the ignition, turn it to the ON position, and then long-press the power button on the handlebar display.
- To power off: Long-press the power button on the handlebar display until it turns off, then turn the key to the OFF position and remove it.
2.2. Display Functions
The 5.4-inch high-resolution LCD display provides essential riding information:
- Speed: Current riding speed.
- Battery Level: Indicates remaining battery charge.
- PAS Level: Shows the current Pedal Assist System level (1-3).
- Mileage: Displays total trip distance.
- Error Codes: Alerts to system malfunctions.
2.3. Speed Modes and Pedal Assist System (PAS)
- Use the 'S' button on the handlebar controls to cycle through three speed modes (PAS levels 1-3).
- PAS 1: Lowest assist, suitable for casual riding and maximum range.
- PAS 2: Medium assist, balanced power for varied terrain.
- PAS 3: Highest assist, for maximum power and speed (up to 28 MPH).
2.4. Throttle Operation
The ebike features a twist throttle on the right handlebar. Twist the throttle towards you to engage the motor without pedaling. The throttle can achieve speeds up to 28 MPH.
2.5. Gear Shifting
Your ebike is equipped with a 7-speed Shimano gear system. Use the thumb shifter on the right handlebar to change gears. Downshift for easier pedaling on inclines and upshift for higher speeds on flat terrain.
2.6. Lighting System and Braking
- Headlight: Press the headlight button on the left handlebar to turn the LED headlight on/off.
- Turn Signals: Use the left/right arrow buttons to activate the sequential turn signals.
- Brakes: The ebike has mechanical disc brakes (160mm rotors) on both front and rear wheels. Squeeze the brake levers on the handlebars to engage. The brake levers also feature motor cut-off for safety.
3. Maintenance
Regular maintenance ensures the longevity and safe operation of your QNUT Retro Ebike.
3.1. General Care
- Keep the ebike clean by wiping it with a damp cloth. Avoid high-pressure washing directly on electrical components.
- Store the ebike in a dry place, away from direct sunlight and extreme temperatures.
3.2. Tires and Brakes
- Tire Pressure: Regularly check and maintain the recommended tire pressure for your 20"x4.0" fat tires. Proper inflation improves ride quality and prevents punctures.
- Brake Inspection: Inspect brake pads and rotors for wear. Ensure brake levers are responsive and cables are not frayed. Adjust as needed.
3.3. Drivetrain and Suspension
- Chain: Keep the chain clean and lubricated to ensure smooth gear changes and prevent wear.
- Suspension: Periodically check the front suspension fork and rear shock for proper function and any signs of damage.
3.4. Battery Care
- Charge the 48V 18Ah lithium battery regularly, even if not in use, to prolong its lifespan.
- Avoid completely draining the battery.
- Store the battery in a cool, dry place.
4. Troubleshooting
If you encounter issues with your ebike, refer to this section for common problems and solutions.
4.1. Power Issues
- Ebike not turning on: Ensure the battery is fully charged, securely installed, and its power switch is ON. Check that the key is turned to the ON position.
- Motor not engaging: Verify the PAS level is set above 0. Check all electrical connections for looseness. Ensure brake levers are not partially engaged, as they have motor cut-off sensors.
4.2. Braking Problems
- Brakes feel weak: Inspect brake pads for wear and replace if necessary. Check brake cables for proper tension and adjust if loose.
- Squealing brakes: Clean rotors and pads. Ensure rotors are not bent or damaged.
4.3. Display Errors
If an error code appears on the display, consult the full user manual for specific code meanings and troubleshooting steps. Common issues may relate to motor, controller, or battery communication.
5. Specifications
| Feature | Detail |
|---|---|
| Motor | 1500W Peak / 500W Nominal Brushless Hub Motor |
| Battery | 48V 18Ah Removable Lithium Battery |
| Max Speed | 28 MPH |
| Range | 60-90 Miles (Pedal-Assist Mode) |
| Tires | 20"x4.0" Fat Tires |
| Frame Material | Carbon Steel |
| Suspension | Dual (Front Suspension Fork, Rear Shock) |
| Brakes | Mechanical Disc Brakes (160mm Rotors) |
| Display | 5.4-inch High-Resolution Smart LCD |
| Gearing | 7-Speed Shimano |
| Max Load Capacity | 330 lbs |
| Ebike Weight | 77.2 lbs |
| Dimensions (LxWxH) | 66.14 x 15.35 x 48.03 inches |
6. Warranty and Support
6.1. Limited Warranty
The QNUT Retro Ebike comes with a limited warranty. Please refer to the warranty card included in your packaging for specific terms and conditions regarding coverage and duration.
6.2. Customer Support
For any questions, technical assistance, or warranty claims, please contact QNUT customer support:
- Email: support@qnutbike.com