MingYi.officeGas Cylinder Heavy Duty for Herman Miller Classic Aeron Chair as Replacement

It's been almost a year and my very expensive chair is still working as good as new. I work from home so every single day I'm at my desk for 8-12 hours. This has stood the test of time. I watched videos as to how to remove the older parts (that was hard part), and this installed perfectly. My desk is higher than normal and I got a model that extends further and I am so happy I did. This is definitely worth every penny, especially since I don't have to spend $800-1200 for a new chair!

Wonderful replacement, no noise, works like it should. Pretty easy to install, the hard part is getting the old one out though lol

This China aftermarket gas cylinder for Aeron was EASY to install, fit perfectly and worked immediately upon installation. I DID have an extremely difficult time removing the original HM cylinder from the chair. It had been there for decades. The online videos made the removal look way easier than it was. It took a number of overnight WD-40 soaking, the biggest heaviest pipe wrench I could get and a LOT of aggression in numerous sessions to incrementally move that old cylinder a few millimeters at a time. When it finally came out, the new one slipped in like a charm, what a surprise, it was a good quality purchase. The chair being an original HM Aeron would cost close to $1K to replace...and was a Great Incentive to put up with the hassle.

The cylinder doesn't drop down into the base as far as the original, so it does sit a little high. I would say it's still usable for 5'10" and above.Also agree that the original is difficult to remove, so consider using some WD-40 and letting it sit for a bit before attempting the pipe wrench, which you absolutely will need. There are no threads, so you can turn the cylinder either direction.After you drop this product into the chair's base you will want to be sure you have taken off the black plastic cap, which should reveal the green tip that goes into the bottom of the seat. Once together, if the chair goes up and down without moving the lever, you will need to loosen the set screw which will require an allen key. For this you need to remove the plastic cover under the seat. One half turn was enough for me.

NO JOKE you need a 24 inch pipe wrench to get the old one off!!!!...i tried many things before breaking down and buying the 12 dollar pipe wrench at harbor freight......channel locks...NO....vise grips....NO....die grinding flat spots and trying the biggest wrench i have with a pipe on it....NO IT WILL NOT WORK......YOU NEED THE PIPE WRENCH!!! or a slot on press(like the one, other cylinder makers included with the new cylinder) ....note you should NEVER bang on the bottom of the chair mount (where the chair meets the shaft, ONLY bang on the base that has wheels to separate that part and only bang on that AFTER you have the chair part off the top of the shaft).....WD40 is your friend....flip the chair over and spray right where the shaft meets the chair base before trying to remove it.after you get the new cylinder in......the instructions tell you to loosen the screws where the adjustment handle is.....do NOT do this....look up what type of chair you have and adjust it the right way....for mine i have the center pin set up.....all i had to do was pop the top off the chair mount and unscrew a Allen key to make the chair stay at a set height and work when the adjustment handle was pulled....i tried loosing the screws like the instructions said and it did NOTHING.....it does so little that i had forgotten to tighten them up before adjusting the screw on the base and after i remembered, screwing them back in i did not have to readjust the center screw at all.....this cylinder is HIGHER then the stock one....me being 6'8 this is the frist time my herman miller is as high as i need!!!! LOVE IT!!! but it drops to the same low spot as the old one so you will be able to get the height you had out of it....your biggest problem will be getting the old off.....putting the new one on is a joke....UPDATE.....well its been 2 years and i have spent the last year trying to get a replacement....it will not hold very long and drops like the one i tried to replace....all i get is Emails telling me to loosen the lever under the chair to stop the cylinder from dropping at random times.....i took the lever OFF the chair and it still drops....seller will not replace unit....

25 year old Herman Miller Aeron chair that's done right be me all this time finally gave up the ghost a few days ago, the cylinder extended to its full height in its dying gasp and wouldn't go down and when I sat down on it I wobbled around disconcertingly. Being uneducated about the cylinder replacement I tried to force it down until it ended up all the way down and wouldn't go back up, laugh. I watched the replacement videos and thrilled to the prospect of using my large pipe wrench for the second time. New one arrived and boy the reviews and testimonials about removing old crusted cylinders was really spot on in my case. It took WD-40 and multiple angle attempts, I think I finally did it by pulling the wrench towards me like I was rowing! Once that was done, and knocking out the old cylinder from the legs with a hammer it was an easy peasy replacement. Note, remember to take off the protective tip on the new cylinder so you expose the green part. I had to adjust the set screw as others have w/ a 5/32 hex wrench, I didn't have to take off the seat I just popped the shroud off and wrenched it from the back. Now I'm back in business with my old war-horse. Will it be another 25 years? We'll see. Recommended. (j4.)

Stopped working after 3 months, I weight about 200 lb. Horrible product, wouldn't recommend.

The new cylinder works fine. The old cylinder was stuck to the bottom of the chair, not the base. Pipe wrench wouldn't work. Had to remove the height adjustment assembly, then I beat on the top of the old cylinder with a hammer and chisel.