1. Introduction
This manual provides detailed instructions for the assembly, operation, and maintenance of your SIHOO Ergonomic Office Chair, Model M90C-102. Please read this manual thoroughly before assembly and use to ensure proper function and longevity of your chair.
Figure 1: SIHOO Ergonomic Office Chair M90C-102
2. Product Components
Verify that all components are present and undamaged before beginning assembly. If any parts are missing or damaged, please contact customer support.
- Backrest Assembly
- Seat Cushion Assembly
- Headrest
- Armrests (Left and Right)
- Gas Lift Cylinder
- Star Base
- Casters (Wheels)
- Mechanism Plate
- Screws and Tools (Allen Wrench)
Figure 2: Chair Components
Figure 3: Safety Spare Parts Overview
3. Setup and Assembly
Assembly typically involves eight steps. Follow the included graphical instructions carefully. Ensure all screws are tightened securely, but do not overtighten.
- Insert casters into the star base.
- Place the gas lift cylinder into the center hole of the star base.
- Attach the mechanism plate to the underside of the seat cushion using the provided screws.
- Mount the armrests to the seat cushion. Pay attention to left and right orientation.
- Attach the backrest to the seat cushion assembly.
- Insert the assembled seat and backrest onto the gas lift cylinder.
- Attach the headrest to the top of the backrest.
- Test all adjustments to ensure proper function.
4. Operating Instructions (Adjustments)
The SIHOO M90C-102 chair offers multiple adjustment options to customize your seating experience.
4.1. Seat Height Adjustment
To adjust the seat height, pull the lever located under the right side of the seat upwards. While holding the lever, raise or lower the seat to your desired height. Release the lever to lock the height. The seat height can be adjusted by approximately 4 inches (10 cm).
4.2. Backrest Recline and Tilt Lock
The backrest can recline between 90° and 123°. To recline, pull the lever on the left side of the seat upwards and lean back. Release the lever at your desired angle to lock the recline position. To return to an upright position, pull the lever again and lean forward.
Figure 4: Reclining Adjustment
4.3. Backrest Height Adjustment
The backrest height can be adjusted to accommodate users of different heights. Lift the backrest upwards in increments to find the optimal position for your lumbar support. It features a three-gear height adjustment mechanism.
Figure 5: Backrest Height Adjustment
4.4. Dynamic Lumbar Support
The chair features adaptive elastic lumbar support that automatically adjusts its support strength based on body weight and contact angle. This provides continuous support to the lower back.
Figure 6: Dynamic Lumbar Support
4.5. 3D Armrest Adjustment
The armrests are adjustable in three dimensions: height, forward/backward, and swivel. Use the buttons or levers on the armrests to make these adjustments, allowing for optimal arm and elbow support.
Figure 7: 3D Armrest Adjustment
4.6. Headrest Adjustment
The headrest can be adjusted for height and angle to provide support for your neck and head. Position it to comfortably support the curve of your neck.
Figure 8: Headrest Adjustment
5. Maintenance
Regular maintenance helps preserve the appearance and functionality of your chair.
- Cleaning: Wipe clean with a damp cloth. Avoid harsh chemicals or abrasive cleaners. For mesh areas, a soft brush can be used to remove dust.
- Inspection: Periodically check all screws and bolts to ensure they are tight. Retighten if necessary.
- Moving Parts: Ensure the casters roll smoothly and the gas lift operates without obstruction.
Figure 9: Breathable Mesh Material
6. Troubleshooting
If you encounter issues with your SIHOO M90C-102 chair, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Chair does not adjust height | Gas lift cylinder malfunction or lever not engaged. | Ensure the height adjustment lever is fully pulled. If the issue persists, the gas lift may need replacement. |
| Backrest does not recline or lock | Recline mechanism jammed or lever not engaged. | Check the recline lever for obstructions. Ensure the mechanism is free to move. |
| Chair feels unstable or wobbly | Loose screws or uneven assembly. | Inspect all connection points and tighten any loose screws. Ensure the chair is assembled correctly on a flat surface. |
| Casters do not roll smoothly | Debris in casters or damaged casters. | Clean any hair or debris from the caster wheels. If damaged, casters may need replacement. |
For issues not listed here or if solutions do not resolve the problem, please contact SIHOO customer support.
7. Specifications
| Feature | Detail |
|---|---|
| Brand | SIHOO |
| Model Name | M90C-102 |
| Color | Grey |
| Product Dimensions (D x W x H) | 25.98" x 25.59" x 47.24" |
| Maximum Weight Recommendation | 300 Pounds |
| Back Style | Solid Back with Mesh |
| Special Features | Adjustable Headrest, 3D Armrests, Dynamic Lumbar Support, Reclining Backrest |
| Material | Breathable Mesh, Sponge (Fill Material) |
| Furniture Base Movement | Swivel |
| Recommended Uses | Office, Home Office |
| Product Care Instructions | Wipe Clean |
| Item Weight | 49.9 pounds |
8. Warranty and Support
The SIHOO Ergonomic Office Chair M90C-102 comes with a 3-year warranty. This warranty covers manufacturing defects and component failures under normal use.
For warranty claims, technical support, or any questions regarding your product, please contact SIHOO customer service through their official website or the retailer where the product was purchased. Please have your model number (M90C-102) and proof of purchase available when contacting support.
