[Closed] Brand-X dropper post- can't remove the cartridge- any ideas?

Have tou got a pick of the top of the post where the seat cradle sits? Did you have a 10mm nut or an allen headed bolt there?

Thanks. Its an allen-headed bolt:

You need to undo that bolt at the top. It's what holds the cartridge in. The cartridge will just pull out easily by hand after that.

Thanks peteza, but unfortunately that doesn't work- the cartridge rotates at the same time as the bolt/screw. Something needs to grip the cartridge.

Mine did that. Did you manage to get it to loosen just the slightest?

I got frustrated and just put everything together again. Rode it for a while and then when I tried again it managed to have enough grip to come out.

I remember thinking when I fitted the new cartridge they seemed to have updated the design so it wouldn't happen again but can't remember what the update was

Thanks tabletop. No, I've only got as far as the posts above. When you tried again, had the cartridge descended a bit more to allow you to grip it, or was it just as far in as before?

No hadn't descended any further.

Sorry no real help to be honest. For some reason when I tried again the bolt just unscrewed in the threads instead of spinning the cartridge. Maybe by using it it had more 'bite' I don't lnow

No probs, thanks. I think I may try just lightly jamming the cartridge against the sides, with something like lolly sticks or similar. Cheers for the input.

Try pushing something against the bottom of the cartridge to stop it spinning while you undo the bolt. You'll need to get the foam ring out of the way first. Something like a thin plastic tyre lever should work, although if the cartridge is knackered I guess you could use whatever you like as it doesn't matter if you damage it.

There's probably a tool, or a 'correct' way to do this, but I don't know what it is and this generally always works.

Maybe if you re-assemble it that may be enough to stop it turning while you undo the bolt. Could try in compressed and extended position.

Do you have an impact driver (for screws)?
Or can you borrow one?

Using that on the hex bolt may work where constant turning just spins the cartridge.

If you're near Chapel / Whaley Bridge I've got one you can try?

try putting it back in the bike , the seatpost clamp might squeeze it enough to hold it a bit to allow you to undo the bolt

Thanks all.

In the end, the application of an electric drill and stud remover sorted it.

Had this exact problem yesterday. In the end I cut a plastic wine bottle cork in half - reduced it down in size and shoved both halves up the underneath the cartridge. Stopped it spinning just enough to get the bolt out.

Thanks Guandax! Bearing this in mind for the future.