Introduction
Welcome to the HAPPYRUN G300 Pro Electric Dirt Bike user manual. This guide provides essential information for the safe assembly, operation, maintenance, and troubleshooting of your electric dirt bike. Please read this manual thoroughly before your first ride to ensure optimal performance and safety.

The HAPPYRUN G300 Pro Electric Dirt Bike, shown here in Camo, is designed for off-road performance.
Safety Information
Operating an electric dirt bike requires adherence to safety precautions. Always wear a certified helmet, eye protection, gloves, and appropriate riding gear. Familiarize yourself with local laws and regulations regarding electric dirt bike usage. Do not operate the bike under the influence of alcohol or drugs. Always perform a pre-ride inspection as detailed in the maintenance section.
- Always wear a helmet and protective gear.
- Inspect the bike before each ride.
- Understand and obey all local traffic laws and regulations.
- Maintain a safe speed and distance from other vehicles and obstacles.
- Avoid riding in adverse weather conditions.
Setup and Assembly
The G300 Pro is designed for straightforward assembly, arriving 85% pre-assembled. You will primarily need to install the front wheel and handlebar. This process typically takes about 30 minutes and does not require special tools. A step-by-step video guide is available online for visual assistance.
- Carefully remove all components from the packaging.
- Attach the front wheel to the fork, ensuring all fasteners are securely tightened.
- Install the handlebar, aligning it correctly and tightening the stem bolts.
- Perform an initial safety check of all connections and moving parts.

The electric bike and its battery are shipped separately to ensure safe transportation. Delivery times for each package may vary.
Operating Instructions
Powering On/Off
To power on the bike, locate the power button on the display or battery and press it. The full-color dashboard will illuminate, indicating the bike is ready for operation. To power off, press and hold the power button.

The full-color dashboard provides essential riding information at a glance.
Riding Modes
The G300 Pro offers versatile riding modes to suit different terrains and preferences:
- Mixed Riding Mode: Combines throttle and pedal assist for extended range and varied performance.
- Pure Electric Mode: Utilizes throttle only for maximum power and speed, offering approximately 45 miles of range.
- Pedal Assist (PAS) Mode: Provides electric assistance while pedaling, extending range up to 70 miles.

Choose between 'Stealth Mode' for urban environments and 'Beast Mode' for off-road adventures.
Speed Control and Braking
The bike features a 6500W peak brushless motor, capable of reaching speeds up to 50 MPH. Speed is controlled via the throttle. For stopping, the G300 Pro is equipped with dual hydraulic disc brakes, providing reliable and quick stopping power in various conditions.

Dual hydraulic disc brakes ensure rapid and controlled stopping.
Battery and Range
The removable 72V 30Ah (2160Wh) battery provides a range of 70+ miles in mixed riding mode. Charging to 80% takes approximately 2 hours. The swappable design allows for carrying a spare battery to extend your adventure.

The 72V 30Ah battery offers extended range and features a BMS safety system and IP65 waterproofing.
Maintenance
Regular maintenance ensures the longevity and safe operation of your HAPPYRUN G300 Pro. Always ensure the bike is powered off before performing any maintenance.
- Battery Charging: Charge the battery fully after each ride. Use only the provided charger.
- Tire Pressure: Check tire pressure before each ride and maintain it according to the recommended levels (refer to tire sidewall for specifics).
- Brake Inspection: Regularly inspect brake pads and rotors for wear. Ensure hydraulic brake fluid levels are adequate and brakes respond effectively.
- Chain Tension: Check and adjust chain tension periodically to prevent slippage and excessive wear.
- General Cleaning: Clean the bike with a damp cloth after riding, avoiding direct high-pressure water on electrical components.
- Suspension Check: Inspect the 43mm inverted forks and dual rear shocks for any damage or leaks.

Key components like brakes, suspension, and the display require regular inspection.
Troubleshooting
This section addresses common issues you might encounter with your G300 Pro. For unresolved problems, please contact our support team.
| Problem | Possible Cause | Solution |
|---|---|---|
| Bike does not power on | Low battery, loose battery connection, power button issue | Charge battery, ensure battery is securely seated, check power button functionality. |
| Motor not engaging | Throttle issue, motor cable disconnected, sensor malfunction | Check throttle connection, inspect motor cables, contact support if issue persists. |
| Brakes feel weak | Worn brake pads, low hydraulic fluid, air in brake lines | Inspect/replace brake pads, check fluid levels, consider professional brake service. |
| Unusual noises during operation | Loose components, chain issues, motor problem | Inspect all fasteners, check chain tension and lubrication, contact support for motor concerns. |
If you encounter issues not listed here or require further assistance, our online support team is available to provide clear instructions within 1 business day.
Specifications
Detailed technical specifications for the HAPPYRUN G300 Pro Electric Dirt Bike:
| Feature | Specification |
|---|---|
| Model Name | G300PRO |
| Motor | 6500W Peak Brushless Motor |
| Battery | 72V 30Ah (2160Wh) Removable Lithium Battery |
| Top Speed | Up to 50 MPH |
| Max Range | 70+ Miles (Mixed Riding Mode) |
| Charging Time | Approx. 2 hours to 80% |
| Load Capacity | 350 lbs |
| Brakes | Dual Hydraulic Disc Brakes |
| Suspension | 43mm Inverted Forks (Front), Dual Rear Shocks |
| Frame Material | Stainless Steel |
| Bike Type | Electric Bike |
| Age Range | Adult |
| Number of Speeds | 5 |
| Intended Riding Terrain | Mountain Terrain |

Key dimensions and weight specifications for the G300 Pro.
Warranty and Support
HAPPYRUN stands behind the G300 Pro with comprehensive support and warranty:
- Returns: 30-day no-hassle returns.
- Warranty: 365-day warranty on the motor and battery.
- Online Resources: Access to a detailed online manual and video library for common adjustments and maintenance.
- Customer Support: For unresolved issues, email our support team. Responses are typically provided within 1-2 business days. Customer support is provided for the lifetime of the product.
For further assistance, please visit the official HAPPYRUN store or contact customer service directly.



