I bought a 2nd hand bike a few years ago that came with a Rockshox dropper. My own fault I’ve never removed it when servicing the bike, but the dropper started to sag recently, so decided it was time for a service.
Couldn’t budge it. Tried all the ideas and suggestions on here and YouTube, still couldn’t move it. Finally resorted to a cold chisel and 2lb mash hammer- still no joy.
By this point the setpost is knackered anyway, so I put the frame in the vice and drilled through the post, pushed a 12mm bolt though the hole and battered it with the mash hammer. Finally, it slowly came up and out, but there was no surface rust or pitting on the post, it was clean and I was trying to understand why it had become stuck solid. It’s at this point I have my WTF moment. The seatpost was 31.6mm dia, but my frame has a 30.9mm dia seatpost.
Why would someone do that?