1. Introduction
Thank you for choosing the True Fit 502D Foldable Treadmill. This manual provides essential information for the safe assembly, operation, and maintenance of your new fitness equipment. Please read this manual thoroughly before using the treadmill and keep it for future reference.
2. Safety Instructions
To ensure your safety and prolong the life of your treadmill, please observe the following precautions:
- Always consult with a physician before starting any new exercise program.
- Place the treadmill on a flat, stable surface with adequate clearance around it.
- Keep children and pets away from the treadmill during operation.
- Wear appropriate athletic footwear and clothing.
- Use the safety key at all times. Attach it to your clothing before starting your workout.
- Do not operate the treadmill if it is damaged or malfunctioning.
- Unplug the treadmill from the power source when not in use or before cleaning/maintenance.
- The maximum user weight capacity for this treadmill is 130 kg. Do not exceed this limit.
3. Package Contents
Verify that all components are present and undamaged before proceeding with assembly:
- True Fit 502D Treadmill Main Unit
- User Manual (this document)
- Power Cord
- Tool Kit (for assembly)
- Safety Key
- Massage Belt (if applicable to your model variant)
- Sitting Exercise Seat (if applicable to your model variant)
4. Assembly Instructions
Assembly is required for this treadmill. Please follow these steps carefully. It is recommended to have two people for assembly.
- Unpack Components: Carefully remove all parts from the packaging and lay them out on a clean, flat surface. Ensure all components listed in Section 3 are present.
- Attach Upright Posts: Secure the upright posts to the base frame using the provided bolts and tools from the tool kit. Do not overtighten.
- Install Console: Mount the console onto the top of the upright posts. Connect any necessary cables from the console to the main unit.
- Secure Handrails: Attach the handrails to the console and upright posts, ensuring they are firm and stable.
- Connect Power: Once fully assembled, connect the power cord to the treadmill and then to a grounded electrical outlet.
- Initial Check: Before first use, ensure all bolts are tightened, and the running belt is centered and tensioned correctly.

Image: The True Fit 502D Treadmill in an unfolded state, highlighting its compact design for home use. The console displays digital readouts, and the running deck is visible. Key features like 1.75 HP (3 HP Peak) motor, 100 kg max user weight, 1-12 km/hr speed, and 44x16 inch running area are noted on the right side of the image.
5. Operating Instructions
5.1. Basic Operation
- Power On: Plug in the treadmill and flip the main power switch (usually located at the front base). The console will light up.
- Attach Safety Key: Clip the safety key to your clothing and place the magnetic end onto the designated area on the console. The treadmill will not start without the safety key in place.
- Start Workout: Press the "START" button on the console. The belt will begin to move at a low speed.
- Adjust Speed: Use the "+" and "-" buttons to increase or decrease the speed. The speed range is 1-12 km/hr.
- Stop Workout: Press the "STOP" button to gradually slow down and stop the belt. Alternatively, pull the safety key to immediately stop the treadmill in an emergency.
5.2. Folding and Storage
The True Fit 502D is designed for easy folding and storage, making it suitable for small spaces.
- Power Off: Ensure the treadmill is completely stopped and unplugged.
- Lift Deck: Carefully lift the running deck from the rear until it locks into an upright position.
- Secure: Ensure the locking mechanism is engaged to prevent accidental unfolding.
- Move: Use the transport wheels (if available) to move the folded treadmill to your desired storage location.
5.3. Using the Massage Belt and Sitting Exercise Seat
(Note: These features may vary by model variant.)
- Massage Belt: Attach the massage belt to the designated points on the treadmill frame. Stand in front of the belt and activate the massage function via the console (if available).
- Sitting Exercise Seat: Position the seat securely on the treadmill frame. Use it for seated exercises as instructed by a fitness professional.
6. Maintenance
Regular maintenance ensures optimal performance and longevity of your treadmill.
- Cleaning: Wipe down the treadmill surfaces with a damp cloth after each use. Avoid abrasive cleaners.
- Belt Lubrication: Lubricate the running belt every 3-6 months, or after 100-200 hours of use, using silicone lubricant. Refer to the specific instructions for your model.
- Belt Tension and Alignment: Periodically check the running belt for proper tension and alignment. Adjust as needed using the provided tools and following the instructions in the full manual.
- Motor Cover: Keep the motor cover free from dust and debris to ensure proper ventilation.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Treadmill does not power on. | Power cord not plugged in; main power switch off; safety key not in place. | Ensure power cord is securely plugged in. Turn on the main power switch. Place the safety key on the console. |
| Running belt slips or hesitates. | Belt tension too loose; belt requires lubrication. | Adjust belt tension according to the full manual. Lubricate the running belt. |
| Unusual noise during operation. | Loose components; motor issue; belt friction. | Check and tighten all bolts. Lubricate the belt. If noise persists, contact customer support. |
8. Specifications
| Brand | True Fit |
| Model Name | 502D (STH-1200 from image) |
| Motor Power | 2.25 HP (Continuous) / 3 HP (Peak) |
| Maximum Speed | 12 km/hr |
| Speed Range | 1 - 12 km/hr |
| Maximum User Weight | 130 kg |
| Running Area | 44 x 16 inches |
| Product Dimensions (Unfolded) | 140 cm (Depth) x 60 cm (Width) x 120 cm (Height) |
| Item Weight | 43 kg |
| Material | Alloy Steel |
| Display Type | LED |
| Connectivity | Bluetooth, Power Cord |
| Special Features | Foldable, Heavy Duty, Massage Belt, Sitting Exercise Seat |
| Assembly Required | Yes |
| Country of Origin | China |
9. Warranty and Support
The True Fit 502D Treadmill comes with a 5-year warranty from the date of purchase. This warranty covers manufacturing defects under normal use conditions.
For warranty claims, technical support, or replacement parts, please contact True Fit customer service. Keep your proof of purchase for warranty validation.
Contact information for True Fit customer service can typically be found on the product packaging or the official True Fit website.