If a chair that used to hold its height now slowly drops while you're sitting in it, the cause is almost always the same part: the gas lift cylinder. It's one of the most common issues in office chairs — and one of the most misunderstood, since it's often assumed the whole chair needs replacing when it's actually a single, repairable component.

What's actually happening

The gas lift is a pressurised cylinder that allows a chair to adjust height and absorb the initial weight of sitting down. Over years of daily use, the internal seal can wear, causing it to slowly lose pressure — the chair still moves up when the lever is released, but gradually settles lower under weight instead of holding position.

This is a mechanical wear issue, not a design flaw on its own — every gas lift will eventually wear out. What varies significantly is how long that takes, and that comes down to the quality of the component and how much daily load it's rated for.

Why it happens faster on cheaper chairs

A gas lift rated for light, occasional use will wear out considerably faster under genuine 8-hour daily commercial use than one designed and tested for that load. This is part of what AFRDI Level 6 testing actually verifies — not just how the chair looks or feels initially, but how components like the gas lift, castors and mechanism perform under sustained, repeated commercial use over time.

A chair that sinks within the first year or two of daily office use is usually a sign the gas lift (and often the broader mechanism) wasn't specified for the load it's actually seeing.

Can it be fixed?

In most cases, yes — a worn gas lift is a replaceable part, not a reason to replace the whole chair. Whether that's straightforward depends on:

  • Whether the chair uses a standard-fit gas lift or a proprietary one that's harder to source
  • Whether the supplier stocks spare parts for the specific chair model
  • The age and general condition of the rest of the chair — if the gas lift has failed and the frame or mechanism is also worn, a full replacement may be more practical

This is one of the practical reasons spare-parts availability is worth asking about before buying a chair fleet, not after something fails — a chair that can be kept in service with a $50–100 part replacement is a much better long-term outcome (and lower environmental impact) than one that has to be replaced entirely.

What to check before buying replacement chairs

If sinking chairs are prompting a fleet review, it's worth checking on any replacement seating:

  • What AFRDI level is the chair rated to, and does that match your actual daily use pattern?
  • Does the supplier stock spare parts (gas lifts, castors) for the model you're buying?
  • What does the warranty cover if a mechanism fails within the warranty period?

Corporate Chair Systems chairs are backed by a lifetime warranty and built for genuine daily commercial use. Get in touch if you're dealing with a fleet of ageing or failing chairs and want to talk through replacement options.