Never lose your Brompton butt plug again!

OGs know that the old bromptons came with a similar style seatpost bung which was better since it would never come out. But I think I weighed it before and it was like 40g.

I finally decided to design and 3D print my own and wanted it to get close to the same weight as the new standard one. It’s just .6g heavier but I could probably optimize it a bit more haha

It uses a titanium bolt to pull the spreader cone thing to expand the prongs so it won’t just come off like the current one which is only (loosely) friction fit.

I still need to take it out on a ride but it feels way more secure, can’t pull it off even if I tried. So I would be way more confident keeping some tools or supplies like pump/tubes/zip ties in there than just the normal bung.

Also another pro is that this allows third party posts without a flared base to get that functionality back; mainly the preset height sleeve.