Does the Office Chair Sink When Sitting Down?

The office chair may sink when sitting down. Here are the specific reasons for analysis:

Aging or poor sealing of the gas spring is the core reason
The lifting function of an office chair relies on a gas spring (also known as a gas lift or hydraulic rod). It is filled with high-pressure nitrogen gas and maintains stable pressure through a sealing structure. When the gas spring ages due to long-term use, the internal oil seal may wear out, causing slow leakage of high-pressure nitrogen gas, or the sealing structure may fail, preventing the gas pressure from being maintained at its original level. At this point, the seat surface will gradually sink under the weight of the human body, and the sinking speed is related to the degree of wear and tear of the gas spring. This sinking is a normal wear-and-tear phenomenon during use and usually cannot be restored through simple repairs; the gas spring needs to be replaced to solve the problem.

Loose screws at the connection points may cause instability but not regular sinking
If the screws at the connection points between the gas spring and the five-star base (the base) or the seat chassis are loose, it will lead to instability in the overall structure of the chair, manifested as wobbling or a slight sinking feeling when sitting. However, such problems usually do not cause regular automatic sinking but rather local looseness or abnormal noises. If a user finds that the chair sinks regularly (for example, slowly sinking to a fixed height every time they sit down), it is more likely to be caused by a gas spring failure rather than a connection point problem.

Other potential factors (less common)
In extremely rare cases, if the filler inside the gas spring is not high-pressure nitrogen gas (for example, some low-quality products may be filled with ordinary air), or if there are design defects in the gas spring (such as an unreasonable sealing structure), it may also accelerate gas leakage or cause abnormal pressure. In addition, extreme usage environments (such as high temperatures or high humidity) may accelerate the aging of the gas spring, but such situations need to be judged in combination with the specific product material and usage conditions.

Summary
The main reason for the sinking of an office chair after sitting down is the aging or sealing failure of the gas spring, which is a normal wear-and-tear phenomenon. If the chair only wobbles slightly without regular sinking, it is advisable to first check whether the screws at the connection points are loose. If the sinking is obvious and persistent, it is recommended to contact after-sales service to replace the gas spring. During daily use, avoiding frequent height adjustments or overloading can extend the lifespan of the gas spring.