Office Chair Bottom Drop

The most common cause of an office chair 'bottom drop' (sinking automatically while sitting) is the aging or poor sealing of the gas lift rod, leading to the leakage of high-pressure nitrogen gas inside or the wear of the oil seal, which in turn fails to maintain the locking pressure.

Cause Analysis

The gas lift rod is the core component of an office chair's lifting system. It is a sealed cylinder filled with high-pressure nitrogen gas and a small amount of lubricating oil, enabling lifting and height locking through changes in gas pressure. When the sealing ring ages or wears out, the gas lift rod cannot effectively maintain the locking pressure, resulting in slow sinking, weak rebound, or stuttering under the weight of the human body. Additionally, the failure of the gas lift rod's seal, the leakage of internal inert gas, or metal structure fatigue may also cause the overall height of the seat to decline. If the gas lift rod is damaged, there may also be gas leakage, inability to lock the seat height, slow sinking, or sudden collapse. In extreme cases, inferior products may even pose a risk of explosion.

Self-Inspection Methods

1. Determine the Problem Type: If only the seat cushion is sunken and soft, it may be due to the aging and collapse of the filling material (such as foam); if the entire seat height drops slowly or suddenly, it indicates a fault in the gas lift rod.
2. Check the Status of the Gas Lift Rod:
   • Locking Function: Adjust the height and then release the handle to observe whether the seat sinks on its own or cannot be fixed.
   • Stability: Sit on it and feel if it is tilted (like a seesaw), and if adjusting the armrests or tightening the screws does not help.
   • Appearance and Feel: Observe whether the metal rod body is rusted and whether there is stuttering, stiffness, or weak rebound during lifting.
   • Gas Leakage Sound: If a 'hissing' sound is heard while sitting quietly or operating the lift, it indicates nitrogen gas leakage.

Handling Solutions

1. Filling Material Collapse: Replace the internal foam or springs, with an estimated cost of around 200-500 yuan.
2. Gas Lift Rod Fault:
   • Contact the official after-sales service (free repair or replacement may be available during the warranty period).
   • Replace it with a qualified new gas lift rod on your own (ensure the specifications match and prioritize products with SGS, TUV certifications, or that comply with the GB/T 2280-2016 standard).

Safety Tips

It is strictly prohibited to disassemble, drill holes in, or repair a faulty gas lift rod on your own, as it is under high pressure inside and improper operation may pose an explosion risk. If the gas lift rod shows signs of oil leakage, abnormal noise, or obvious looseness, stop using it immediately and replace it.