Hi everyone,

I have several height-adjustable bar stools like the ones shown in the attached photos, and they have developed the same problem.

The stools use a lever underneath the seat to adjust the height. When I pull the lever without sitting on the stool, the seat rises normally and can be adjusted to its maximum height. However, once I sit on it, the mechanism does not seem able to hold the pressure/height anymore.

Under my weight, the seat gradually sinks until it reaches the lowest possible position. If I stand up and operate the lever again, it rises normally, but the same thing happens as soon as I sit down.

The stools are otherwise in good condition, so I would prefer to repair them rather than replace them.

From what I understand, these stools probably use a gas-lift/pneumatic cylinder similar to an office chair, but I have never disassembled this type of mechanism.

I would appreciate some advice on:

  • Is this symptom usually caused by a worn or failed gas-lift cylinder?
  • Could the adjustment lever or valve mechanism be keeping the cylinder slightly open instead?
  • Is there any practical way to repair/recondition the existing cylinder, or is replacement normally the only solution?
  • Are these cylinders generally standardized, or would I need to measure the existing one before ordering a replacement?
  • What measurements/specifications should I check to find a compatible replacement?
  • How difficult is it to remove the old cylinder from the base and seat mechanism without damaging the stool?

I have several identical stools, so if the cylinders are the problem, I would ideally like to repair all of them rather than replace the entire set.

Photos attached showing the stools, adjustment lever, base and central column.

Any advice on diagnosing the problem before I start taking them apart would be very helpful.

  • Lupus108@sh.itjust.works
    6·
    6 hours ago

    It’s a little weird it’s all of them not just one or two, so maybe someone has a better idea, but the symptoms sound like it’s a gas cylinder problem. Afaik they sometimes get a little dust and dirt in the seals and don’t seal off proper any more. But since it’s all of them the gas cylinders might just be cheap or not suited for the task.

    I don’t know if you can repair the cylinders themselves, I’d be a little a lotta careful, since those are built to handle some weight they can be under a fair amount of pressure. So disassembling one of the cylinders might will be dangerous, if you don’t know what you’re doing

    There are several different sizes of those cylinders, so you’d need to measure one of them before ordering. I’d just look up what measurements are listed for those cylinders online and then disassemble one stool and take the same measurements. Other than that they should be replaceable fairly easy.

    That’s the knowledge I accuired online when my beloved office chair started to develop the same issue, but since it still functions most of the time I never got around to actually disassemble it, so take everything I said with a grain of salt and maybe get a second opinion. Good luck!

    edit: after looking at the other comment I emphasized the dangers those cylinders can inherit, I still think that replacing them will be fairly easy since the replacement parts are offered online alongside instructions how to

    • Gladaed@feddit.org
      6·
      6 hours ago

      Disassembly is quite dangerous and can be lethal.

      Cue video of the guy getting a surprise vaginoplasty from an office chair.

    • Cursed_Fig@lemmy.world
      4·
      6 hours ago

      So disassembling one of the cylinders might be dangerous.

      This. If I were you I’d set one to the height I wanted and then shim it. With that “upside down” style it’d hold tight, but you’d lose the air cushion.