Office Chair Missing Wheels

When an office chair is missing wheels, you can follow these steps to replace them and pay attention to relevant considerations:

I. Confirm Wheel Type and Size

1. Type Identification: Invert the chair and observe the wheel-axle connection method. Snap-ring wheels have a circular groove at the top of the axle and emit a 'click' sound when pressed; threaded wheels have visible external threads.
2. Size Matching: Common wheel diameters are 5cm (for light chairs), 6cm (for medium chairs), and 7.5cm (for heavy chairs). The international standard for axle diameter is Φ11mm, with an allowable diameter error of ±0.5cm. An axle error exceeding 0.2mm can lead to unstable installation.

II. Prepare Tools

• Snap-ring wheels: No tools required; a screwdriver can be used to assist in prying the snap ring.
• Threaded wheels: A 6-inch adjustable wrench is needed; if severely rusted, WD-40 lubricant can be sprayed.
• Special cases: If base screws need to be removed, a screwdriver or wrench is required.

III. Remove Old Wheels

1. Snap-ring wheels: Insert a screwdriver into the gap between the axle and the chair leg, pry the snap ring until a 'click' sound is heard, then pull it out vertically.
2. Threaded wheels: Use a wrench to grip the base of the axle and rotate it counterclockwise at a 45-degree angle; if rusted, spray lubricant first.
3. Base screws: Use the appropriate tool to remove them, taking care to protect components such as the gas cylinder.

IV. Install New Wheels

1. Snap-ring wheels: Press vertically until a 'click' sound is heard.
2. Threaded wheels: Rotate clockwise until fully tightened.
3. Gap treatment: If there is a gap between the wheel and the axle, it can be filled with adhesive.

V. Test and Adjust

1. Function test: Push the chair to check for noise (should be below 45 decibels on tiled floors) and rolling smoothness (no stuttering for 10 consecutive meters).
2. Stability check: Ensure the bottom of the gas cylinder is at least 2cm above the ground, with a diameter error not exceeding 1cm.
3. Height adjustment: Adjust the chair height according to needs.

Precautions

• Material selection: For hard floors (wood/tile), choose PU wheels; for carpets, choose nylon wheels; families with children can choose wheels with brakes, and gaming chairs can choose double ball-bearing wheels.
• Safe operation: Keep the chair balanced to avoid tipping over; protect other components when removing the base.
• Emergency handling: If the interface does not match, sand the metal axle or wrap with Teflon tape to temporarily increase the diameter.

Purchase Recommendations

• Cost-effectiveness: Ordinary nylon wheels cost about 3 yuan each and have a lifespan of 6-12 months; a set of high-quality PU wheels (5 pieces) costs about 15 yuan and has a lifespan of over 3 years.
• Certification standards: Prioritize products that have passed SGS certification, with heavy metal content meeting the EU EN71-3 standard.
• Replacement recommendation: Replace all wheels at once to ensure consistent performance.