Office Chair Middle Sinking

Office chair middle sinking usually refers to the middle part of the chair seat sinking or the support structure failing, resulting in an uneven seat surface. This can be caused by gas lift rod failure, base damage, seat material aging, or improper installation.

Gas Lift Rod Failure

The gas lift rod is the core component for adjusting the height of an office chair. If the internal seals age or the gas pressure is insufficient, it can lead to uneven force on the seat surface, causing the middle part to sink. Common causes of gas lift rod failure include seal wear from long-term use, internal gas leakage, or hydraulic oil deterioration. At this point, check if the gas lift rod is leaking gas (this can be judged by pressing the lift button and observing the rebound speed). If there is a fault, replace it with a gas lift rod of the same specification and avoid self-repair to prevent safety hazards.

Base Damage

The base connects the gas lift rod to the seat. If the welding points come off, the springs break, or the structure deforms, it will reduce the support force of the seat. Base damage is often caused by long-term overloading or external impacts, such as frequent jumping or heavy object pressure. When inspecting, observe whether the base has cracks, deformation, or looseness. If there is structural damage, contact a professional repair technician to replace the base components.

Seat Material Aging

Seat materials such as sponge and mesh fabric may collapse or lose elasticity after long-term use, especially in the middle area that is frequently under pressure. Material aging is manifested as seat depression, slow rebound, or surface damage. For such problems, handle them according to the material type: for sponge seats, add a cushion for temporary repair, but for long-term use, it is recommended to replace the seat; for mesh fabric seats, if they are broken, replace them as a whole to avoid uneven force due to local repair.

Improper Installation

If the screws are not tightened, the components are not aligned, or the gas lift rod is not fully inserted into the base during the assembly of the office chair, it may cause the seat to tilt or the middle part to sink. Installation problems are common in new chairs or when reassembling after moving. Check whether all connection points are firm, especially the fixing screws of the gas lift rod and the base, and the seat and the base. When reinstalling, follow the steps in the instruction manual to ensure that each component is in the correct position.

Handling Suggestions: First, locate the cause of the fault through observation and simple tests (such as pressing the seat to judge the material elasticity and checking the lift function of the gas lift rod), and then choose to replace components, reinforce the structure, or adjust the installation method according to the specific problem. If it involves the repair of core components such as the gas lift rod and the base, it is recommended to contact the brand's after-sales service or a professional repair technician to avoid safety risks caused by improper operation.